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4. Amendment to City Code Chapters 1, 7, 13, 18, 19 & 20 as a Result of Adoption of the 2nd Generation Surface Water Mgmt Plan CITY OF CHANHASSEN 7700 Market Bou levard PO Box 147 Chanhassen, MN 55317 Administration Phone: 952.227.1100 Fax: 952.227.1110 Building Inspections Phone: 952.227.1180 Fax: 952.227.1190 Engineering Phone: 952.227.1160 Fax: 952.227.1170 Finance Phone: 952.227.1140 Fax: 952.227.1110 Park & Recreation Phone: 952.227.1120 Fax: 952.227.1110 Recreation Center 2310 Coulter Boulevard Phone: 952.227.1400 Fax: 952.227.1404 Planning & Natural Resources Phone: 952.227.1130 Fax: 952.227.1110 Public Works 1591 Park Road Phone: 952.227.1300 Fax: 952.227.1310 Senior Center Phone: 952.227.1125 Fax: 952.227.1110 Web Site www.ci.chanhassen.mn.us 4 - A'1ID MEMORANDUM To: Todd Gerhardt, City Manager ~ I:} Lori Haak, Water Resources Coordinator From: Date: January 8, 2007 Re: Code Revisions Resulting from Adoption of Second Generation Surface Water Management Plan (SWMP) REQUESTED ACTION Staff recommends the City Council adopt a motion adopting ordinances amending Chapters 1,7, 13, 18,19 and 20 of the City Code to bring the code into compliance with the City's Second Generation Surface Water Management Plan. Staff also recommends the City Council adopt a motion approving summary ordinances for Chapters 1, 18, 19 and 20 for publication purposes. A simple majority vote of City Council members present is required to adopt the amendments; however, a 4/5ths vote is requiredforapproval of the summary ordinances forpublicationpurposes. Over the past two years, the City of Chanhassen has been wor update its 1994 Surface Water Management Plan. The Second Generation Surface Water Management Plan (SWMP) was recommended for approval by the Planning Commission on August 15, 2006 and was adopted by the City Council on August 28, 2006. The SWMP is available on the City's website at www.ci.chanhassen.mn.us. The SWMP update process involved a comprehensive review of the goals, policies and standards that were implemented as part of the 1994 Plan. The Second Generati SWMP recommended a number of changes to the standards that are current! mployed by the City in the areas of erosion and sediment control, stormwater management and wetland protection. The recommended revisions to the City Code.will help the City to implement its Second Generation SWMP and achieve the goals set forth therein. PLANNING COMMISSION SUMMARY The Planning Commission held a public hearing on December 5,2006 to review the draft code revisions and ordinancesandtoteceive public comment. No one was present to make comments during the public hearing. At that meeting, the Planning Commission voted 7 toO to recommend adoption of ordinances amending Chapters 1, 7, 13, 18, 19 and 20 of the City Code to bring the code into compliance with the City's Second Generation Surface Water Management Plan. The City 01 Chanhassen · A growing community with clean lakes, quality schools, a charming downtown, thriving businesses, winding trails, and beautiful parks. A great place to live, work, and play. Code Revisions Resulting from Second Generation SWMP January 8, 2007 Page 2 of3 DEVELOPMENT COMMUNITY COMMENTS On December 11, 2006, staff sent the proposed ordinance revisions to representati ves from Lennar Corporation, K. Hovnanian Homes and Plowshares Development, LLC. The representatives were asked to provide comments by December 29,2006 so they could be incorporated in the City Council packet. Comments were received from Mr. Matt Goldstein of Lennar Corporation (Attachment 2). The salient items that arose from the comments are: 1. Impervious surface definition: The revised definition of "impervious surface" is overly restrictive in that it does not provide credit against lot coverage percentages for the use of pervious pavers, porous pavement and other similar materials. This concern has been raised by residents and developers alike. The proposed definition does not represent a change in City policy; however, it does articulate the manner in which "impervious surface" has been interpreted historically by staff. Staff has discussed the City's interpretation at length internally and with other communities. Communities that have given credit against lot coverage have struggled with several issues including: improper installation that results in no or limited infiltration; replacement of porous systems with traditional impervious surfaces; and determination of appropriate credit amounts. Because water quality is directly influenced by the amount of imperviousness in the watershed, staff supports the proposed definition of "impervious surface" and encourages developers to increase lot sizes in proposed developments to accommodate the needs of prospecti ve buyers. It should be noted that pervious pavers, porous asphalt and other similar surfaces are allowed and encouraged within the City, even if a credit towards lot coverage is not given. 2. New wetland classification system: The proposed wetland classifications are unique to the City of Chanhassen and vague. The classifications were developed as a result of the Minnesota Board of Water and Soil Resources (BWSR) refining the Minnesota Routine Assessment Method (MnRAM). The proposed classifications are linked directly to the outcomes of MnRAM, which is a peer- reviewed and state-accepted method of wetland assessment. The existing classifications (Pristine, Natural, Ag/Urban) were established in the early 1990s by the consultants working on the original Surface Water Management Plan and are therefore more subjective. 3. Revised wetland buffer requirements: The proposed wetland buffer requirements are overly restrictive and may be considered a taking in certain development proposals. There is little evidence to support increased buffer widths. Setbacks should be reduced if buffer strip widths increase. Buffer width averaging would provide a more flexible alternative to the current proposal. The proposed buffer requirements are less than or equal to the minimum recommended widths set forth in the Wetland Management Classification System that was designed to accompany MnRAM. Scientific literature maintains that 50 feet is the absolute minimum buffer width for wildlife habitat. Additionally, a literature review has indicated that "buffer widths of 50 feet generally will provide adequate protection from suspended solids for maintaining high water quality." Around the City's most sensitive water resources, it is reasonable to expect that this level of protection be required. No changes are proposed to the Code Revisions Resulting from Second Generation SWMP January 8, 2007 Page 3 of 3 required setbacks. The intent of the setbacks is to provide a useable area for property owners adjacent to wetlands. This minimizes the potential for future encroachment into buffer areas. A verage buffer widths have been eliminated because they are difficult to administer as permits are issued for individual lots. Additionally, it is confusing for property owners if the standard is not consistent around the entire basin. 4. Retaining walls near wetlands: Retaining walls and limited land alteration should be allowed within the buffer strip, especially where buffer strips are being created rather than preserved. Current City code does not allow placement of retaining walls within wetland setbacks. Staff recognizes that this is unrealistic based on the topography of Chanhassen, so language permitting retaining walls within wetland setbacks is proposed. With prior approval, alterations would be allowed within buffer strips where the buffer strip is deemed to be unacceptable in its current condition. The City's letter in response to Mr. Goldstein's comments is included in this report as Attachment 3. RECOMMENDA TION Staff recommends that the City Council adopt the following motions: "The City Council adopts ordinances amending Chapters 1,7,13,18,19 and 20 of the City Code to bring the code into compliance with the City's Second Generation Surface Water Management Plan." and "The City Council approves the summary ordinances for Chapters 1, 18, 19 and 20 for publication purposes." ATTACHMENTS 1. Strikethrough/Bold versions of proposed revisions to chapters 1, 7, 13, 18, 19 and 20 of Chanhassen City Code. 2. Letter from M. Goldstein to L. Haak, dated December 28, 2006 3. Letter from L. Haak to M. Goldstein, dated December 29,2006 4. Summary Ordinances for chapters 1, 18, 19 and 20. 5. Ordinances amending chapters 1,7, 13, 18, 19 and 20. G:\ENG\Lori\Surface Water\2006 SWMP Update\Code Updates\010807 CC Exec Summary.doc CHAPTER 1, GENERAL PROVISIONS. Sec. 1-2. Rules of construction and definitions. Administrative Wetland Permit means authorization to perform an activity that is classified as a Wetland Management Activity. Securing an Administrative Wetland Permit does not exempt the permittee from obtaining any and all other necessary permits (e.g., United States Army Corps of Engineers, Minnesota Pollution Control Agency). (20) iAg/Urearl ','v'ctlarlds see HT-etlarlds, ag/blrea71.. Boardwalk means a linear structure extending across wetlands or lakes that is not supported by posts or poles, but floats or rests upon floats without causing detrimental impacts to the wetland or lake. (20) City Wetland Inventory means the official City Wetland Inventory Map depicting the approximate location and extent of wetlands within Chanhassen. A copy of this map shall be maintained on the City's GIS database, with both hard and electronic copies being made available for public review upon request. (20) Erosion control means best management practices employed to prevent erosion including, but not limited to: soil stabilization practices, limited grading, mulch, temporary or permanent cover, and construction phasing as defined in the MPCA General Construction Permit. (7, 19) GIS means Geographic Information System, such as ArcView. (20) Hardcover see Impervious surface. Impervious surface means any material that substantially rcduces or prcvents the infiltration of storm v:ater. It shall include, but not be limited to, gravel driveways, parking area, buildings and structures. any material that reduces or eliminates water infiltration when compared to local native soil surface and structure. Impervious surfaces include, but are not limited to: bituminous and concrete driveways, pavers of all material, compacted aggregate, non-porous landscape underlayment, retaining walls, buildings, rooftops, patios, landscape stepping stones or flagstones, driveways, pool decking and any other structures. Exemptions include decks when installed without impervious surface below, landscape rock or mulch with pervious underlayment. Manage 1 wetlands means high-quality wetlands that should be protected from development and other pressures of increased use, including indirect effects of development. Maintaining natural buffers will help to retain the significant function these wetlands provide. In the event that impacts to these wetlands cannot Page 1 of 3 be avoided, replacement ratios for mitigation should exceed the state-required minimums. (20) Manage 2 wetlands means wetlands that provide medium functional levels and the wetland extent should be maintained. These wetlands often provide optimal restoration opportunity. (20) Manage 3 wetlands means wetlands that have been substantially disturbed and have the lowest functions and values. (20) Minnesota Routine Assessment Method (or MnRAM) means Minnesota Routine Assessment Method for Evaluating Wetland Functions (MnRAM Version 3.0), or future versions. (20) MPCA means the Minnesota Pollution Control Agency. "VaturGll wetlands see Wetlands, naturGll. NPDES permit means the Minnesota Pollution Control Agency's (MPCA's) National Pollutant Discharge Elimination System (NPDES) Phase II Municipal Separate Storm Sewer System (MS4) permit. Preserve wetlands means exceptional and highest-functioning wetlands, or those sensitive wetlands receiving conveyed stormwater runoff that have yet retained a medium level of vegetative diversity/integrity. These wetlands are those that should be preserved in (or improved to) their most pristine or highest functional capacity with wide, natural buffers, in perpetuity. (20) Pristine l'.'etlands see Wetlands, pristine. Sediment control means best management practices employed to prevent sediment from leaving site including, but not limited to: silt fence, sediment traps, earth dikes, check dams, subsurface drains, pipe slope drains, storm drain inlet protection and temporary or permanent sediment basins as defined in the MPCA General Construction Permit. (7, 19) Storm Water Pollution Prevention Plan (SWPPP) means a plan for stormwater discharge that includes erosion prevention measures and sediment controls that, when implemented, will decrease soil erosion on a parcel of land and decrease off- site nonpoint pollution, as defined in the MPCA General Construction Permit. Surface Water Management Plan (SWMP) means the most recently adopted version of the Chanhassen Surface Water Management Plan. Utilized water body see Water body, utilized. Page 2 of 3 Water body, utilized. Utilized '.yater bodies created for the specific purpose of surface '.'/ater runoff retention and/or ',','ater quality improvements. These '.vater bodies are not to be classified as wetlands even if they take on wetland characteristics. 'AT etland alteration permits shall not be required to undertake work on these '.vater bodies. (20) WCA agent means the city staff member responsible for the administration of the Minnesota Wetland Conservation Act. (20) Wetland Conservation Act (or WCA) means the Wetland Conservation Act of 1991, as amended (M.s. ~ 103F.612 et seq.), and the accompanying rules of the Minnesota Board of Water and Soil Resources (Minnesota Rules Chapter 8420, as amended). (20) Wetland alteration means draining, grading, excavating, filling, removing healthy native vegetation, or otherwise altering or destroying a wetland. (20) Wetland management activity means planting seed or live plant material, burning, chemically treating, removing topsoil or utilizing other means for the sole purpose of managing native plant communities and/or eradicating invasive, nonnative vegetation. (20) WetlaNds, ag/urbaN. Wetlands that have been influenced by agricultural or urban (residential, commercial, or industrial) land usage are called ag/urban. Influences include: ovemutrification, soil erosion and sedimentation, and water quality degradation. .\s a result of these influences there is a loss of plant species diversity, overcrowding and domination by invasive species such as reed canary grass, and reduction in wildlife habitat. (20) WetlaNds, Natural. Natural wetlands are still in their natural state and typically shov,' little sign of impact from surrounding land usage. The ','egetati','e community of these wetlands is characterized by a diversity of plant species with mixed dominance of species. Other key factors include: presence of natural indicator species, good \','ildlife habitat, and being aesthetically pleasing. (20) V/etlan.ds, pristiNe. \Vetlands that exist in a natural state and have special and unusual qualities worth protecting at a high level are called pristine. These qualities include: outstanding vegetation community, natiye species population, rare or unusual species present, and habitat for rare 'wildlife species. (20) Page 3 of 3 CHAPTER 7, BUILDINGS AND BUILDING REGULATIONS Sec. 7-19. Plans and specifications. The building official may require that plans and specifications, required by the Minnesota State Building Code, include a survey of the lot upon which the proposed building or construction is to be done, prepared and attested by a registered surveyor. An original signature is required on the certificate of survey. The survey shall provide the following information unless otherwise approved by the administrative authority: (1) Scale of drawing and north arrow; (2) Legal description of property; (3) Dimensions and bearing of front, rear, and side property lines; (4) Front, rear, and side yard setback dimensions of all proposed structures; (5) Location of all existing structures on the property, boulevards, streets and right- of-way, including but not limited to sanitary and storm manholes, hydrants, catch basins, power poles, phone boxes, fences, and any encroachments; (6) Outside dimensions of proposed structure(s) including decks, porches, retaining walls (include elevations at bottom of footing and top of wall), stoops, stairs, cantilevers, fireplaces, bay and bow windows, egress window wells; (7) Location of a benchmark stake established by the surveyor at the front setback line within 20 feet of the proposed structure. Maintenance of the benchmark stake once established by the surveyor shall be the responsibility of the permit applicant; (8) Location of stakes established by the surveyor on side property lines at: a. Front setback line. b. Front building line. c. Rear building line. The maintenance of these stakes once established by the surveyor shall be the responsibility of the permit applicant; (9) Location of first floor elevation of buildings on adjacent lots. Vacant adjacent lots shall be labeled as such; (10) Location of all easements of record including but not limited to tree preservation, wetland conservation, cross-access, etc.; (11) Existing and proposed elevations at the following locations; a. Each lot corner. b. Top of curb or centerline of roadway at each lot line extension. c. Center of proposed driveway at curb. d. Grade at corners of proposed structure. e. Lowest floor level, top of block, garage slab. (12) Indication of direction of surface water drainage by arrows and impervious surface calculations for the lotor parcel; (13) Tree removal, tree preservation and grading plan if required by the development contract; (14) Wetland boundaries with ordinary high water level and one hundred-year flood elevation if applicable; (15) Driveway grade (minimum--0.50 percent, maximum--ten percent); Page 1 of 5 (16) All trees in excess of six inches in diameter (diameter measured at four feet above grade); (17) All custom-graded lots and lots deviating from the approved grading plan shall require an as-built survey submitted to the city prior to issuing a certificate of occupancy; (18) Wetland buffer areas and wetland or lake setback dimensions; (19) Other information as required by the city. (20) Location and type of erosion and sediment control measures to be installed by permit holder. (Ord. No. 23-B, S 6.01, 2-23-81; Ord. No. 167, S 5,4-27-92; Ord. No. 317, S 3,4-23-01; Ord. No. 324, S 2, 7-9-01; Ord. No. 351, S 4, 11-24-03) Sec. 7-22. Grading, erosion and sediment control. (a) A satisfactory erosion and sediment control plan and grading plan consistent with the city's Best Management Practices Handbook Surface Water Management Plan must be approved by the city engineer or designee before a building permit is issued for construction, if the construction will result in disturbing the soil. The erosion and sediment control plan shall be illustrated and summarized, by the applicant at the time of application. Guidance documents shall be listed in the Surface Water Management Plan and on the city website. To guarantee compliance with the plan a $500.00 cash escrow or letter of credit, satisfactory to the city, shall be furnished to the city before a building permit is issued. The escrow amount may be greater than $500.00 if, after review of the site, the city deems it necessary to require a greater amount to guarantee compliance. The maximum escrow allowable per parcel is $5,000.00 per acre. The city may use the escrow or draw upon the letter of credit to reimburse the city for any labor or material costs it incurs in securing compliance with the plan or in implementing the plan. If the city draws on the escrowed funds, no additional building permits shall be issued until the pre-draw escrow balance has been restored. The city shall endeavor to give notice to the owner or developer before proceeding, but such notice shall not be required in an emergency as determined by the city. (b) The grading and erosion control plan must be consistent with the approved grading plan for the plat in which the property is located, if any. ,\reas where the finished slope 'Nill be steeper than five units horizontal to one ','ertical shall be specifically noted. '^Also, location of erosion control devices shall be clearly labeled. lA maintenance plan is required for all erosion and sediment control measures. Erosion and sediment control measures IllUSt be maintained to meet designed performance. (c) Every effort shall be made to minimize disturbance of existing ground cover. No grading or filling shall be permitted within 40 feet of the ordinary high water mark of a water body unless specifically approved by the city. ,^JI disturbed areas shall be replaced with a minimum of four inches of topsoil or black dirt. To minimize the erosion potential Page 2 of 5 of exposed areas, restoration of ground cover shall be provided within five days after completion of the grading operation: (d) Every effort shall be made during the building permit application process to determine the full extent of erosion control required. However, the city engineer may require additional controls to correct specific site related problems as normal inspections are performed. (e) All erosion control noted on the approved plan shall be installed prior to the initiation of any site grading. Noncompliance with the grading and erosion control plan shall constitute grounds for an order from the city engineer to halt all construction. All failing erosion and sediment control measures shall be remedied \vithin 21 hours of notification on construction sites. Temporary erosion and sediment control measures shall be removed within 30 days of stabilization. (f) All construction activity that results in disturbance of the ground shall comply with the city's Construction Site Erosions and Sediment Control Best Mal1agement Practices Handbook, as amended Surface Water Management Plan. (g) If the erosion and sediment control measures have not been installed or maintained properly, the city reserves the right to stop further work. Peak discharge rates may 110t increase from the existing two , ten and one hundred year storm e','ents and the one hundred year, ten day snowmelt. (h) Compacted soils shall be broken up to a depth greater than six il1ches prior to final site stabilization. (i h) Seed and mulch shall be applied no later than September 15 of each year. Sod shall be installed 110 later than October 15 of each yoar. Temporary or permanent erosion control shall be installed on all exposed soils not actively being graded consistent with conditions of NPDES construction permit or as detailed in the 2005 MN DOT construction specification handbook, specification 2575. U) Landlocked stormviUter basins shall be designed to hold back to back one hundred year storms. (k) Proposed projects shall not result in an increase in the bounce or duration of inundation downstream. (1) Runoff rates shall be maintainod to the predevelopment rates for the one hundred yoar storm. (Ord. No. 176, S 1, 10-12-92; Ord. No. 351, S 5,11-24-03) Sec. 7-34. Exempt earth work. Page 3 of 5 Earth work that is exempt from obtaining a permit pursuant to section 7-33 shall: (1) Comply with the city's erosioh control standards. (2) Maintain natural or existing drainage patterns. (3) Comply with the city's other ordinance requirements including tree preservation and wetland protection. (4) Obtain all applicable permits as required and work within the requirements of the permits. (Ord. No. 128, S 1,5-14-90) Sec. 7-35. Applications for earth work permits. (a) An application for an earth work permit shall be processed in accordance with the same procedures specified in the City Code relating to interim use permits except that earth work of more than 50 cubic yards of material but less than 1,000 cubic yards of material in a 12-month period may be approved administratively. (b) An application for a permit shall contain: (1) The name and address of the operator and owner of the land, together with proof of ownership. If the operator and owner are different, both must sign the application. (2) The correct legal description of the property where the activity is proposed to occur. (3) A certified abstract listing the names of all landowners owning property within 500 feet of the boundary of the property described above. (4) Specifications of the following, using appropriate maps, photographs and surveys: a. Proposed grading plan. b. Proposed stockpile sites. c. The physical relationship of the proposed designated site to the community and existing development. d. Site topography and natural features including location of watercourses and water bodies. e. The description and quantity of material to be excavated. f. The depth of water tables throughout the area. g. The location and depth of wells and buried garbage, water, and fill. (5) The purpose of the operation. (6) The estimated time required to complete the operation. (7) Hours and months of operation. (8) A tree survey indicating the location and type of all trees over six inches in caliper. In a heavily wooded area only the boundaries of the tree areas must be indicated on the survey. (9) An end use landscape plan and interim screening plan for the operation period. (10) The plan of operation, including processing, nature of the processing and equipment, location of the plant source of water, disposal of water and reuse of water. (11) Travel routes to and from the site and the number and type of trucks that will be used. Page 4 of 5 (12) Plans for drainage, erosion and sediment control, sedimentation and dust control. (13) A restoration plan providing for the orderly and continuing restoration of all disturbed land to a condition equal to or better than that which existed prior to the earth work. Such plan shall illustrate, using photographs, maps and surveys where appropriate, the following: a. The contour of the land prior to excavation and proposed contours after completion of excavation and after completion of restoration. b. Those areas of the site to be used for storage of topsoil and overburden. c. A schedule setting forth the timetable for excavation of land lying within the extraction facility. d. The grade of all slopes after restoration, based upon proposed land uses, and description of the type and quantity of plantings where revegetation is to be conducted. e. The criteria and standards to be used to achieve final restoration as well as intermittent stabilization. (14) A statement identifying the applicant's program to insure compliance with the permit conditions, method of response to complaints and resolving conflicts that may arise as a result of complaints. (15) Unless exempt under Minnesota Rules, an environmental assessment worksheet, if required by the city. (16) A wetland alteration permit, if required by the City Code, which shall be processed concurrently with the excavation permit application. (17) Other information required by the city. (c) Applicants for earth work permits involving less than 1,000 cubic yards of material must only furnish the information specified in subsections (b)(1), (2), (4a), (5), (6), (7), (8), (12), (13), (16) and (17). (Ord. No. 128, ~ 1,5-14-90) Page 5 of 5 CHAPTER 13, NUISANCES Sec. 13-2. Illustrative enumeration. (a) The following are nuisances affecting health, safety, comfort or repose: (1) Accumulations of manure, animal feces, refuse, garbage, tin cans, bottles, junk, debris or other waste which are kept so as to result in offensive odors or unsightly conditions to the discomfort and annoyance of adjacent property owners or the public; (2) Garbage cans and privy vaults which are not fly-tight; (3) Dumping the contents of any cesspool, septic tank, privy vault or garbage can except at places authorized by law; (4) All noxious weeds, tall grasses, and other rank growths; (5) The throwing, dumping or depositing of any dead animals, manure, garbage, waste, decaying matter, ground, sand, stones, ashes, rubbish, tin cans, paper, or other material of any kind on private or public property; (6) Dense smoke, noxious or offensive fumes or odors, gas, soot, or cinders in unreasonable quantities; (7) Offensive trade and business as defined by statute or ordinance not licensed as provided by law; (8) All public exposure of persons having a contagious disease; (9) The distribution of samples of medicines or drugs unless such samples are placed in the hands of an adult person; (10) All decayed, unwholesome, or contaminated food offered for sale to the public; (11) Carcasses of animals not buried or destroyed within 24 hours after death; (12) The keeping of horses, cattle, swine, sheep, goats, rabbits, dogs, or other animals or fowl so as to result in offense odors or disagreeable noises to the discomfort of adjacent property owners, and allowing any animal or fowl to run at large; "at large" means off the premises of the owner and not under restraint, and "owner" means any person who shall own, harbor, keep or have custody of an animal, or the parents or guardians of a person under 18 years of age who shall own, harbor, keep or have custody of an animal. Cross references: Other animal nuisances, S 5-20. (13) Placing paper, litter or debris on public or private property, or throwing paper, litter or debris from motor vehicles; (14) Causing or permitting any unnecessary noises or annoying vibrations. (15) The pollution of any public well, stream, river, lake, wetland, storm sewer or body of water by chemical, organic, industrial, agricultural, commercial, residential, sewage, yard, construction and animal creamery, or industrial wastes. (16) Breeding sites of the Aedes Triseriatus (tree hole mosquito) including but not limited to: the basal holes of hardwood trees, unused tires (not mounted on wheels), pots, pans, cans, pails, bottles and other containers left outdoors in which water or debris may accumulate; (17) All other acts, omissions, occupations and uses of property which are a menace to the health of the inhabitants of the city or a considerable number thereof. (b) The following are nuisances affecting public morals and decency: (1) Any vehicle used for the illegal transportation of intoxicating liquor; Page 1 of 4 (c) The following are nuisances affecting public peace and safety; (1) Reserved; (2) All buildings, walls and other structures which have been damaged by fire, decay or otherwise to an extent exceeding one-half of their original value, or which are in such a hazardous condition or so situated as to endanger the safety of the public; (3) All explosives, inflammable liquids and other dangerous substances or materials stored or accumulated in any manner or in any amount other than that provided by law or ordinance; (4) All use, possession or display of fireworks except as provided by law or ordinance; (5) All buildings and structures, and all alterations thereof made, erected or altered in violation of ordinances concerning the manner of construction and the materials used therein; (6) Obstructions and excavations affecting the use of public streets, alleys, sidewalks or public grounds, except under such conditions as are provided by ordinance; and any other excavation left unprotected, uncovered or allowed to exist in such manner as to attract children or to constitute a hazard to the public; (7) The piling, storing or keeping of old machinery, wrecked or junked vehicles, or other junk or debris upon open spaces; "junked vehicle" means a vehicle that is not registered and which does not possess a current state automobile license, but the license is not to be the sole factor determining the status of the vehicle; (8) Obstructing traffic and the free use of public streets or sidewalks; (9) All hanging signs, awnings and other similar structures over public streets or sidewalks, or so situated as to endanger public safety, not constructed and maintained as provided by law or ordinance, or without proper permit; (10) Permitting rain, water, ice or snow to fall from any building on any public street or sidewalk or to flow across any public sidewalk; (11) All dangerous unguarded machinery, equipment or other property in any public place, or so situated or operated on private property as to attract minor children; (12) Placing entrance culverts, or doing any act which may alter or affect the drainage of public streets or alleys or the surface or grade of public streets, alleys or sidewalks without proper permit; (13) Making repairs to motor vehicles, or tires in public streets or alleys, excepting only emergency repairs which will not unduly impede or interfere with traffic; (14) Throwing, placing, depositing, or burning leaves, trash, lawn clippings, weeds, grass, or other material in the streets, alleys or gutters; (15) Erecting, painting or placing of unauthorized traffic signs or advertising signs in streets, or alleys or on sidewalks; (16) All trees, hedges, billboards or other obstructions which prevent a clear view of traffic approaching an intersection in sufficient time to bring a motor vehicle driven at a reasonable speed to a stop before the intersection is reached; (17) Any dog which shall kill, wound or harass any other domestic animal; (18) Any dog which habitually barks in such manner as to disturb the peace; (19) Any dog which harasses, chases or molests horses, motor vehicles or persons; (20) To leave any unused ice box, refrigerator, cooler or other box with a door thereon which will exclude air when shut; Page 2 of 4 (21) All other conditions, acts, or things which are liable to cause injury to the person or property. (22) Reserved. (23) Reserved. (24) Nuisance light on residential properties. a. Definitions. In this section: (i) Direct glare means an excessive brightness contrast producing a sensation of visual discomfort resulting from insufficiently shielded light source in the field of view. (ii) Intermittent light means any artificial light which flashes, revolves or fluctuates in such a manner that the variance is easily distinguished by personal observation. (iii) Light source means a device (such as a lamp) which provides visible energy. (iv) Light trespass means light emitted that is visible beyond the boundaries of the property on which the light source is located. (v) Person means an individual, firm, partnership, trustee, agent, association, corporation, company, governmental agency, club or organization of any kind. b. Direct glare and light trespass declared a nuisance. Glare, light trespass and intermittent artificial light impacting on residential properties between the hours of 11 :00 p.m. and 7:00 a.m., which cause loss of enjoyment, comfort or repose, and use of such properties as determined under subsection 13-2(24)c. of this section is declared a nuisance. c. Nuisance determined. (i) Light trespass shall be considered a nuisance when light produces two- tenths horizontal foot candles or more at approximately four feet from the ground or floor surface on other residential property at the property line. (ii) Direct glare shall be considered a nuisance when an artificial light source has not been properly located, shielded, directed or controlled, and as a result there is a direct line of sight between the light source or its reflection and a point five feet above the ground or higher at the property line of other residential property if such intensity causes discomfort or annoyance. (iii) Intermittent light shall be considered a nuisance when it impacts upon a habitable area of other residential property with such intensity and variance as to cause discomfort or annoyance. d. Production of light nuisance prohibited. No artificial light source shall be installed, allowed to be installed or permitted on any property which light sources is an intermittent light source, or due to its intensity or physical characteristics, causes direct glare or trespasses onto a residential property in such a manner as to cause a nuisance during the hours of 11 :00 p.m. through 7:00 a.m. e. Responsibility. It shall be the responsibility of every installer of artificial lights and every owner or occupant of property on which artificial lights are installed to comply with subsection 13-2(24)d. of this section. f. Exemptions. The provisions of subsections 13-2(24)d. and e. of this section shall not apply where: Page 3 of 4 (i) Such lights are caused to be installed by the federal, state or local government or agency, to light publiC ways Or areas for public benefit; or (ii) Such lights are required by law for safety reasons and there is no practical way to control them to eliminate the nuisance. (Ord. No. 22, ~~ 2--5,2-5-68; Ord. No. 22A, ~ 1, 10-8-79; Ord. No. 22B, ~S 1,2,4-15- 85; Ord. No. 159, S 1,2, 11-18-91; Ord. No. 298, S 2,2-14-00; Ord. No. 308, S 1, 7-24- 00; Ord. No. 324, ~ 7, 7-9-01; Ord. No. 373, SS 1--4,4-12-04) Page 4 of 4 CHAPTER 18, SUBDIVISIONS Sec. 18-62. Erosion and sediment control. (a) The development shall conform to the topography and soils to create the least potential for soil erosion. Four inches of topsoil shall be roplaced on all disturbed areas. (b) The smallest practical increment of land shall be exposed at anyone time during development. (c) Detailed requirements for each plat shall be set forth in the development agreement. (d) Subdivision development shall conform to the city's Construction Site Erosion and Sediment Control Best Management Practices Handbook, as amended Surface Water Management Plan. Sec. 18-63. Surface water management. (a) All subdivisions shall comply with the city's surface water management plan dated February 1991 August 2006, which is incorporated herein by this reference. (b) In accordance with the city's surface water management plan as a condition of subdivision approval, subdividers shall pay a water quality and water quantity connection charge. The charge shall be based upon the gross area of the subdivision less the area to be dedicated to the city for ponding, parks and wetland, and right-of-way for state highways, county roads, and local arterial roadways. The connection charges per acre for water quality and water quantity are outlined in subpart (c) 3 of Section 4-30. The subdivision will be given a credit for on-site stormwater quality improvements that are designed to treat runoff from the subdivision to NURP standards. The credit will be calculated.using the following formula: The per acre water quality connection charge will be multiplied by the on-site drainage area for water quality treatment facilities. This value will then be multiplied by 50 percent. The subdivision will also be given a credit for on- site storm water quality improvements that are oversized to treat runoff from property outside the subdivision to NURP standards. The credit will be calculated using the following formula: The per acre water quality connection charge will be multiplied by the off-site drainage area for water quality treatment facilities. This value will then be multiplied by 50 percent. Credit will not be granted if the stormwater from contributing off-site areas is already treated to NURP standards. The water quality connection charges that correspond to the land uses that contribute to the stormwater ponds will be used to calculate credits. The charge for lots oversized due to individual on-site sewage disposal and water systems will be reduced to the charge that would be imposed on a one-half-acre lot. An additional charge will then be imposed if the lot is further subdivided less a credit for the charge previously paid. The charge shall be paid in cash before the subdivision is approved by Page 1 of 2 the city unless the city and subdivider agree that the charge may be assessed against the property. Property being subdivided shall be exempt from the water quality and water quantity connection charges imposed by this section if the charges were paid or assessed in conjunction with a previous subdivision of the property and if the property is not being zoned to a classification with a higher charge. (c) Within the Bluff Creek Overlay (BCO) District, meet the additional purpose, intent and standards of the BCO District. Page 2 of 2 CHAPTER 19, WATER, SEWERS AND SEWAGE DISPOSAL ARTICLE V. STORM SEWERS Sec. 19-101. Unlawful discharge. As provided in this Article and the city's NPDES permit, it shall be unlawful to discharge to any storm sewer any pollutant waters. Sec. 19-102. Regulations for use of storm sewer. (a) No person shall throw, deposit, place, leave, maintain or keep or permit to be thrown, placed, left, maintained or kept, any refuse, rubbish, garbage or any other discarded or abandoned objects, articles, or accumulations, in or upon any street, alley, sidewalk, storm drain, inlet, catch basin, drainage structure, business place, or upon any public or private plot of land so that the same might be or become a pollutant, except in containers, recycling bags, or other lawfully established waste disposal facility. (b) No person shall intentionally dispose of grass, leaves, dirt, or other landscape debris into a lake, wetland, storm water pond, wetland buffer strip, street, road, alley, catch basin, culvert, curb, gutter, inlet, ditch, natural watercourse, ravine, flood control channel, canal, storm drain or any fabricated natural conveyance. (c) No person shall leave, deposit, discharge, dump, or otherwise expose any chemical or septic waste in an area where discharge to streets or the storm sewer system may occur. (d) No person shall use any storm sewer connection to intentionally convey non-storm water to the storm water system. (e) Objects, such as motor vehicle parts, containing grease, oil or other hazardous substances, and unsealed receptacles containing hazardous materials, shall not be stored outdoors. (f) Fuel and chemical residue or other types of potentially harmful material, such as animal waste, garbage or batteries, which is located outdoors shall be removed as soon as possible and disposed of properly. Household hazardous waste shall not be placed in a trash container. (g) No person shall maliciously, willfully or negligently break, damage, destroy, uncover, deface or tamper with any structure, appurtenance or equipment which is a part of the city storm sewer system. (h) The following activities shall be determined exempt from the provisions listed in this article: (1) City staff or city contractors during the course of conducting maintenance activities; and Page 1 of 10 (2) Metropolitan Mosquito Control District during the course of conducting mosquito control activities. Repeal Sections 19-140 through 19-148. ARTICLE VII. SURFACE WATER MANAGEMENT. Sec. 19-140. Purpose. The purpose of this ordinance is to implement standards to achieve the goals and policies set forth in the city's Surface Water Management Plan in order to preserve, protect and improve the city's surface water resources. Sec. 19-141. Development standards. These development standards shall be reflected in plans prepared by developers and/or project proposers in the design and layout of site plans, subdivisions and water management features. Sec. 19-142. Plans required. All plans shall be reviewed and stamped "Approved by the City Engineer" and all applicable permits must be obtained prior to commencing construction. For all newly constructed storm water facilities (ponds, retention areas, infiltration basins, storm sewer, etc.) or existing facilities that are modified, as-built plans shall be prepared by the developer. As-built plans shall be signed and certified by a licensed professional engineer in the State of Minnesota and record drawings shall be provided to the city. Standard details for many typical storm structures (e.g., storm sewer, outlet structures, catch basins, sump manholes, etc.) are available on the city's website. Sec. 19-143. General elements. (a) Hydrologic Analysis 1. Storm distributions and storm volumes for hydrologic analysis shall be based upon Hershfield, D.M., 1961, Rainfall Frequency Atlas of the United States for Durations of 30 Minutes to 24 Hours and Return Periods from 1 to 100 Years, Technical Publication No. 40 (TP-40). 2. Design of major facilities (e.g., ponds, detention areas, retention areas) shall be based on the U.S.D.A. NRCS methods, 100-year return period, 24-hour duration, type II distribution with average soil moisture conditions (AMC-2). The analysis of flood levels, storage volumes and discharge rates for detention basins shall utilize the design storm/freeboard evaluation storm concept. 3. Minor drainage systems (storm sewer) shall be analyzed and designed to protect for the 10 year frequency rainfall, and shall be evaluated for the 100-year frequency Page 2 of 10 rainfall. Full pipe flow analysis shall be used unless special conditions can be demonstrated to consider pressure flow. 4. The Rational Method is the accepted design method for the design of minor systems (storm sewer). The preferred method of design would be a method utilizing a hydrograph approach with factors for land use and soil moisture conditions. NRCS methodology is not acceptable for minor system design unless approved by the City Engineer. S.Landlocked storm water basins shall be designed to hold back-to-back 100-year storms. For landlocked areas, available freeboard and infiltration capacity of in- place soils should be analyzed (if analyzed for unfrozen soil conditions). (b) Peak Discharge Rates 1. Peak storm water discharge rates and storage volumes from any drainage area, watershed, subwatershed, detention basin, wetland or conveyor shall be consistent with the values shown in this plan for the 100-year storm event. 2. No increase in peak discharge rate may result from the proposed project for the 1 or 2-year storm, the 10-year storm and the tOO-year storm event. Variances may be allowed if computations can be provided which demonstrate no adverse downstream effects will result from the proposed system. Cumulative storm depths for the required events are: a) 2- Year = 2.8 inches b) 10- Year = 4.2 inches c) 100-Year = 6.0 inches (c) General Facility Planning 1. Developments shall maximize preservation and use of natural detention areas and regional detention areas shall be used to the greatest practical extent. Multiple purpose detention areas are encouraged to maximize maintenance efficiency within proposed developments while providing the proper flood control and water quality features. 2. The construction of detention basins will involve the direct participation of individual developers. Where regional basins serve multiple properties and may lie outside of the ownership of the specific development, the City and watershed districts will take an active role on implementing policy. Because the basis for the hydrology is based on the developer's grading plan, the developer is required to obtain and submit the certification of a licensed engineer that the detention areas are constructed to the specifications of the approved design. Sec. 19-144. Major facility design elements. (a) .Facility Design Criteria Page 3 of 10 (1) For design or modification Of storm water facilities, the following criteria shall be followed: a. All hydrologic data and computations shall be based on NRCS (formerly SCS) methodology. Computer modeling may be completed using HydroCAD, TR20/TR55, SWMM or comparable City-approved modeling software. b. Hydraulic computations shall be completed using the rational method for storm sewer design, or in commonly used software packages including FHW A HY -8, Geopack, Eagle Point or SWMM compatible software. c. Water quality modeling shall be completed using Pondnet, P8 Urban Catchment Model, SLAMM or comparable software. d. Outlet structure designs shall provide rate controls that limit post-project rates to not exceed existing rates for 1 or 2-year, 10-year, 100-year events and 100- year/lO-day snowmelt. e. An emergency overflow spillway shall be identified and designed to convey storm flows from events greater than the 100-year event. Extreme events (on the order of a 10.0 inch event) shall be analyzed to ensure the emergency overflow spillway will function as designed. An emergency overflow shall be set an elevation at least 1.5 feet below the lowest adjacent low building elevation. f. Maximum 3:1 (H:V) side slopes (see diagram that follows). g. 10:1 (H:V) safety bench from normal water level (see diagram that follows). h. For basins intended to have permanent water levels, a minimum of' four feet of standing water (dead storage depth) and a maximum of ten feet shall be provided. i. Proper allowance shall be made for future access and maintenance. Easements shall be greater than or equal to 20 feet wide. j. Separation between the inlet(s) and outlet shall be maximized to prevent short- circuiting. ,. ," (2) The facility design shall provide adequate live storage to provide protection from the design storm, consistent with lowest building elevation standards. Lowest building floor elevation is defined as the lowest slab elevation for a home or building, including basements and crawl spaces. The lowest building floor elevation for Page 4 of 10 structures adjacent to wetlands arid water bodies shall be an elevation three feet above the 100-year high water level. (3) Newly constructed or modified detention basins shall provide storage volume below the outlet (dead storage) to allow for water quality treatment in accordance with the following, whichever is most restrictive: a. Water quality features meeting the MPCA NPDES construction permit for Permanent Storm Water Management Systems; b. Water quality treatment consistent with NURP criteria (90% removal of TSS and 60% removal of TP for a standard NURP particle size distribution); and/or c. For proposed projects in a watershed that directly discharges to a 'Preserve' water feature (Table 20 of SWMP), NURP plus enhanced treatment is required as listed below: 1. Storm water ponds are required to include a sediment forebay at the inlet. The volume of the sediment forebay should be 5 - 15 % of the permanent pool surface area. The sediment forebay shall be a minimum of 3 feet plus the depth for sediment storage. 2. Projects in watersheds that discharge directly to Assumption Creek must incorporate BMPs as outlined in Appendix A C.l, C.2, C.3 and C.5 of the MPCA NPDES Construction General Permit, and as listed below: 1. During construction. a. All exposed soil areas with a slope of 3:1 or steeper, that have a continuous positive slope to a special water must have temporary erosion protection or permanent cover within 3 days after the area is no longer actively being worked. All other slopes that have a continuous positive slope to a special water must have temporary erosion protection or permanent cover within 7 days after the area is no longer actively being worked. b. Temporary sediment basin requirements described in Part III.B.1-5 of the NPDES Construction General Permit must be used for common drainage locations that serve an area with five (5) or more acres disturbed at one time. 2. Post construction. The water quality volume that must be treated by the project's permanent storm water management system described in Part III.C of the NPDES Construction General Permit shall be one (1) inch of runoff from the new impervious surfaces created by the project. 3. Buffer zone. An undisturbed buffer zone of not less than 100 linear feet from the special water (not including tributaries) shall be maintained at all times. Exceptions from this requirement for areas, such as water crossings or limited water access, are allowed if the Permittee fully documents in the SWPPP the circumstances and reasons that the buffer encroachment is necessary. All potential water quality, scenic and other environmental impacts of these exceptions must be minimized and documented in the SWPPP for the project. 4. Temperature Controls. The permanent storm water management system must be designed such that the discharge from the project will Page 5 of 10 minimize any increase in the temperature of trout stream receiving waters resulting from the 1, and 2-year 24-hour precipitation events. This includes all tributaries of designated trout streams within the section that the trout stream is located. Projects that discharge to trout streams must minimize the impact using one or more of the following measures, in order of preference: a. Minimize new impervious surfaces. b. Minimize the discharge from connected impervious surfaces by discharging to vegetated areas, or grass swales, and through the use of other non-structural controls. c. Infiltration or evapotranspiration of runoff in excess of pre-project conditions (up to the 2-year 24-hour precipitation event). d. If ponding is used, the design must include an appropriate combination of measures such as shading, filtered bottom withdrawal, vegetated swale discharges or constructed wetland treatment cells that will limit temperature increases. The pond should be designed to draw down in 24 hours or less. e. Other methods that will minimize any increase in the temperature of the trout stream. d. For proposed projects in a watershed that directly discharges to an 'Improve l' (Table 20 of SWMP) water feature NURP plus enhanced treatment is required as listed below: 1. Storm water ponds are required to include a sediment forebay at the inlet. The volume of the sediment forebay should be 5 - 15 % of the permanent pool surface area. The sediment forebay shall be a minimum of 3 feet plus the depth for sediment storage. 2. Projects in watersheds that discharge directly to Riley or Bluff Creeks must analyze the downstream system to ensure there is no increase in runoff rates. One way to determine the downstream effects is to extend the analysis downstream to a point where the proposed development represents less than ten percent of the total watershed draining to that point. (b) Skimmers and Outlets 1. Skimming devices should be designed to remove oils and floatable materials up to a one-year frequency event. The skimmer should be set 12 inches below the normal surface water elevation and should control the discharge velocity to 0.5 fps. 2. Outlets shall be evaluated for the need to dissipate energy so as to reduce velocities to permissible levels as allowed by the soil and vegetation. At a minimum, flared end sections should be provided with riprap consistent with Mn/DOT standards. For areas with high flows or where excessive erosion occurs or is anticipated, energy dissipation per Federal Highway Administration standards shall be followed. 3. Riprap shall be provided below the channel grade and above the outfall or channel bottom to insure that riprap will not be undermined by scour or rendered ineffective Page 6 of 10 by displacement. Riprap consisting Of natural angular stone suitably graded by weight shall be designed for anticipated velocities. Riprap shall be placed over a suitable filter material or filter fabric to insure that soil particles do not move through the riprap and reduce its stability. 4. For outlets through berms or roadway embankments and all culverts under public traveled streets, anti-seepage collars shall be used (see diagram in this section). The collars shall be installed so as to increase the creep distance or seepage line along conduit by 15 percent. The locations for the use of collars include: a. All water and pond structures with a pool depth of two feet and two-day duration. b. 250 acre watershed or more. c. Design head of 10 feet or more. Sec. 19-145. Erosion and sediment control. (a) Erosion and Sediment Control Plans 1. An erosion and sediment control plan shall be created for any land disturbing activity. Erosion and sediment control elements shall be implemented before any grading can begin. A schedule of significant grading work will be required as part of the erosion and sediment control plan. 2. The MPCA's most recent version of the NPDES Construction Storm Water Permit shall be used to develop sediment and erosion control plans. Where the NPDES permit conflicts with City standards, the more stringent standard will apply. 3. Site access roads (entrances to construction sites) shall be graded or otherwise protected with silt fences, diversion channels or dikes and pipes to prevent sediment from exiting the site via the access road. Primary site access roads shall be surfaced with crushed rock or wood chips. The rock entrance shall extend for a minimum distance of 75 feet (150 for wood chips) beginning at existing paved surface; additional length may be required as directed by the City. All construction traffic shall utilize the entire length of the rock entrance. 4. Soil tracked from the site by motor vehicles shall be cleaned from paved roadway surfaces at least daily or as needed throughout the duration of construction. Roadway cleaning shall be the responsibility of the party or parties having a permit with the City. 5. Streambank stabilization and stream bed control structures shall be designed based on the unique site conditions present including soil conditions, flow rate, slope, and flow velocity. 6. Where inadequate natural vegetation exists or where it becomes necessary to remove existing natural vegetation, both temporary vegetative and permanent Page 7 of 10 vegetative cover shall be addressed in the plans and specifications and be consistent with the provisions of the NPDES Construction permit. (b) Sediment Basins 1. Detention basins may be used as temporary sediment retention during the construction phase. The design should include providing permanent storage volume for construction and restoration phase sediment accumulation or the removal of the sediment to restore the required permanent pool volume in the detention area. 2. Detention areas intended to permanently trap sediments shall provide excess dead storage beyond the required water quality volume, to allow for sediment accumulation. Sediment basins shall be capable of removing coarse suspended sediment from storm water for all runoff events and the greatest practical grain size (#40 typically). Sediment storage volume should be estimated by the universal soil loss equation and 0.5 tons per watershed acre per year. Volume below the outlet can be estimated by using the runoff volume resulting from a 2.5" rainfall. Sec. 19-146. Wetland elements. (a) Water level fluctuations (peak elevation and duration) for wetlands shall be limited to two feet and duration not to exceed 48 hours so as to prevent the destruction of wildlife habitat and wetland vegetation. (b) Sedimentation basins or sediment removal devices shall be provided prior to discharge into wetlands. (c) Variable bottom contours should be considered to provide deeper holes and flat shallow benches. This feature will provide habitat for diversity of plants and wetland inhabitants for wetland mitigation sites and storm water basins. Secs.19-147-19-199. Reserved. Page 8 of 10 ARTICLE VIII. SURFACE WATER MANAGEMENT Sec. 19-200. Surface water management utility established. Surface water management shall be operated as a public utility pursuant to M.S. S 444.075. Sec. 19-201. Definitions. The following words, terms, and phrases, when used in this article, shall have the meaning ascribed to them in this section, except where the context clearly indicates a different meanmg: Suiface water management budget is the annual budget approved by the city council for surface water management including planning, monitoring, capital expenditures, personnel, and equipment. Suiface water management fee means the quarterly charge for each parcel of nonexempt property in the city for the management of surface water. Utility factor means the ratio of runoff volume, in inches, for a particular land use, to the runoff volume, in inches for a one-third-acre residential lot, assuming a two-inch rainfall and soil conservation service (SCS) "type B" soil conditions. Sec. 19-202. Surface water management fees. The surface water management fees for tax parcels shall be calculated in accordance with section 4-50. Sec. 19-203. Credits. The city council may adopt policies for adjustment of the surface water management fees. Information to justify a fee adjustment must be supplied by the property owner. Adjustment of fees shall not be retroactive. Sec. 19-204. Exemptions. The following land uses are exempt from the surface water management fee: (1) Public right-of-way. (2) Lakes. Sec. 19-205. Payment of fee. Surface water management fees shall be involved quarterly. The amount due as shown on the invoice shall be payable on or before the twentieth day of the month in which the invoice is issued. A penalty of ten percent per quarter shall be added to all accounts that are not paid in full by the due date. The penalty shall be computed on the unpaid balance not paid by the due date at the time each quarterly statement is prepared. Any prepayment or overpayment of charges shall be retained by the city and applied against subsequent fees. Page 9 of 10 Sec. 19-206. Appeal of fee. If a property owner or person responsible for paying the surface water management fee believes that a particular fee is incorrect, such person may file a written appeal with the city clerk. Appeals will be heard by the city council. No adjustment will be made to the utility factor for property classifications 1,2, and 3. Sec. 19-207. Certification of delinquent fees. If a surface water management fee is not paid within three months after a billing is issued, the city council may certify the amount due, together with penalties, to the county auditor to be collected with other real estate taxes on the parcel. Sec. 19-208. Surface water management fund. A separate fund shall be maintained for surface water management fees and expenditures. Page 10 of 10 CHAPTER 20, ZONING. Repeal Sections 20-401 through 20-418. ARTICLE VI. WETLAND PROTECTION. Sec. 20-401. Findings intent; rules adopted by reference. (a). Wetlands help maintain water quality, serve to reduce flooding and erosion, act as sources of food and habitat for a variety of fish and wildlife, and are an integral part of the community's natural landscape. Wetlands provide the aesthetic benefits of open space and can be used to provide a natural separation of land uses. It is the intent of this ordinance to establish a policy of sound stewardship through coordination of regulations that conserve, protect, enhance, and result in the no net loss of these environmentally sensitive resources. In addition, it is the intent of the city to promote the restoration of degraded wetlands. (b). The intent of this ordinance is to avoid alteration and destruction of wetlands. When this is not feasible, mitigation must be provided to recreate the function and value of the lost or altered wetlands. (c). This ordinance is adopted in part to implement the Wetland Conservation Act of 1991, as amended (M.S. ~ 103F.612 et seq.), and the accompanying rules of the Minnesota Board of Water and Soil Resources (Minnesota Rules Chapter 8420, as amended). (d). This ordinance incorporates by reference the act and the rules. Terms used in this ordinance which are defined in the act or the rules have the meanings given there. Sec. 20-402. Purpose. The purpose of this ordinance is to assure the general health, safety, and welfare of the residents through preservation and conservation of wetlands and sound management of development by: (1). Conducting an inventory and classification of all wetlands within the city and maintaining a comprehensive set of official city maps depicting the approximate location and extent of wetlands. (2). Establishing wetland regulations that are coordinated with water quantity and water quality goals and policies of the Chanhassen Surface Water Management Plan. (3). Requiring sound management practices that will protect, conserve, maintain, enhance and improve the functions and values of wetlands within the community. Page 1 of 16 (4). Requiring measures designed to maintain and improve water quality in streams and lakes. (5). Protecting and enhancing the scenic value of wetlands. (6). Restricting, controlling and mitigating the harmful effects of development on wetlands. (7). Allowing only development that is planned to be compatible with wetland protection and enhancement. (8). Providing standards for the alteration of wetlands when alteration is allowed. (9). Educating and informing the public about the numerous benefits and features of wetlands and the impacts of urbanization. (10). Obtaining protective easements over or acquiring fee title to wetlands as appropriate. Sec. 20-403. No net loss. (a). To achieve no net loss of wetland, except as provided under sections 20-417 and 20-418 of this ordinance or authorized by a wetland alteration permit issued by the city, a person may not drain, grade, excavate, fill, burn, remove healthy native vegetation, or otherwise alter or destroy a wetland of any size or type. Any alteration to a wetland permitted by a wetland alteration permit must be fully mitigated so that there is no net loss of wetlands. (b ). Wetlands shall be subject to the requirements established herein, as well as restrictions and requirements established by other applicable city ordinances and regulations. The wetland protection regulations shall not be construed to allow anything otherwise prohibited in the zoning district where the wetland area is located. (c). All activities within the City shall comply with the Wetland Conservation Act of 1991, as amended (M.S. ~ 103F.612 et seq.),and the accompanying rules of the Minnesota Board of Water and Soil Resources (Minnesota Rules Chapter 8420, as amended). Where the requirements of City Code differ from those requirements, the more restrictive shall apply. Sec. 20-404. Official wetland map. (a). The City shall maintain the official City Wetland Inventory, which is hereby adopted by reference. An electronic copy of this map shall be maintained on the Page 2 of 16 City's Geographic Information System (GIS) database, with both hard and electronic copies being made available for public review upon request. (b). The City Wetland Inventory shall identify each basin as one of four management categories: Preserve, Manage 1, Manage 2, and Manage 3. These classifications will be determined using Figure 1.1 "Wetland Management Classification Process Flowchart for Basic Wetland Protection" from Minnesota Routine Assessment Method for Evaluating Wetland Functions (MnRAM Version 3.0), or future versions. (c). The presence or absence of a wetland on the City Wetland Inventory does not represent a definitive determination as to whether a jurisdictional wetland that would be covered by this ordinance is present. Wetlands identified during a site- specific delineation, but not identified by the City Wetland Inventory, are still subject to the provisions of this ordinance. (d). The City Wetland Inventory does not depict delineated wetland boundaries and shall not be used as such. (e). The City Wetland Inventory shall be amended to include any wetlands discovered during the site review process. Sec. 20-405. Wetland delineation. (a). It is the responsibility of the project applicant to determine whether a wetland exists on a subject property. It is the responsibility of the applicant to complete a wetland delineation and submit sufficient documentation of the wetland boundary to the city in a Wetland Delineation Report. Wetland delineations shall be completed by, or under the direct supervision of, a Certified Wetland Delineator. Three (3) hard copies of the Wetland Delineation Report must be submitted to the city's WCA agent. Additionally, an electronic copy of the delineated wetland boundaries must be submitted in a format compatible with the city's GIS database. Wetland delineations shall be valid for three years. Wetland delineations completed more than three (3) years prior may be confirmed and/or updated by a qualified wetland professional through a site visit and submittal of a summary of the findings, a copy of the old delineation and a map depicting both the original and revised wetland boundaries, where applicable. (b). Wetland delineations do not need to be completed for properties adjacent to a proposed development that is under separate ownership. However, sufficient information must be presented to demonstrate that any proposed activities shall not directly or indirectly impact adjacent basins. The applicant shall review readily available information including, but not limited to, the City Wetland Inventory, National Wetland Inventory maps, topographic maps, soil survey maps, and recent and historic aerial photographs in preparing this assessment. Page 3 of 16 Sec. 20-406. Wetland classification. (a). All wetlands delineated under section 20-405 of this ordinance that have not been previously classified shall be classified using the results from the Minnesota Routine Assessment Method for Evaluating Wetland Functions (MnRAM Version 3.0), or future versions. (b). A MnRAM shall be completed by the property owner or applicant for each previously unclassified wetland. An electronic version of the MnRAM evaluation must be submitted to and approved by the city to establish the classification of each wetland prior to any alteration or impact to the wetland. (c). MnRAM 3.0 assessments have been completed by the City as a component of the City Wetland Inventory. Applicants; however, may appeal the determination, and submit a request to change the classification. To do so, the applicant must submit an electronic copy of the MnRAM for each affected basin to the WCA agent. The forms must be filled out by a qualified wetland scientist. The WCA agent will consult with the technical evaluation panel to determine if a change in the classification is warranted. In all cases, the burden to demonstrate the need for a change in classification lies with the applicant. Sec. 20-407. Permit required. (a). No person shall drain, excavate in the permanent or semipermanent flooded areas of open water wetlands, or filla wetland, wholly or partially, or otherwise impact wetlands without first having a wetland replacement plan or other determination approved by the city. Draining, grading, excavating, filling, removing healthy native vegetation, or otherwise altering or destroying a wetland of any size or type not subject to an exemption under section 20-417 of this chapter requires a wetland alteration permit. Activity in a wetland requiring a wetland alteration permit includes, but is not limited to: (1). Construction of new streets and utilities. (2). Creation of ponds or dams and alterations of the natural drainageways of water courses. This shall only be allowed as part of a mitigation project, or to restore or improve the function and value of the wetland. (3). Installation of boardwalks and docks. Docks shall meet the additional requirements in Chapter 6, Article II of the Chanhassen City Code. (4). Discharge of untreated stormwater runoff into wetlands. (5). Changes in wetland hydrology that result in an increase in the ordinary high water level of a wetland by more than 12 inches. Page 4 of 16 (b). The city must be notified at least five business days prior to the use of any form of treatment of wetlands to control nuisance vegetation including chemically treating, burning, mowing or biologically treating wetlands. (1). At the time of notification, a person or company will be required to supply the following information: a. Location of wetland; b. Area of wetland to be treated; c. Name, address and telephone number of the party responsible for treatment; d. Name, address and telephone number of person or persons performing the treatment; e. Date of treatment; f. A list of the type of treatments to be used at such time; g. A statement indicating an understanding of the treatment being applied and its effect on humans, plants and wildlife; and h. A signed consent from all property owners owning property containing or abutting wetland to be treated. (c). The following activities shall be determined exempt from the provisions listed in subpart (b) above: (1) Federal, state or local government staff or contractors during the course of conducting maintenance activities; and (2) Metropolitan Mosquito Control District during the course of conducting mosquito control activities. Sec. 20-408. Exemptions from earth work permit requirements. Earth work completed in accordance with an approved wetland alteration permit is exempt from the requirement to obtain a separate earth work permit. Sec. 20-409. Permit application requirements and decisions. (a). A wetland alteration permit shall not be issued without having been first reviewed by the planning commission and approved by the city council following the review and hearing procedures set forth for conditional use permits and the additional requirement of Minnesota Rules 8420.0230. The applicant shall have the burden of proving that the proposed use or activity complies with the purposes, intent and other provisions of this ordinance. The council may establish reasonable conditions which are specifically set forth in the permit to ensure compliance with requirements contained in this ordinance. Such conditions may, among other matters, limit the size, kind or character of the proposed work; require the construction of other structures; require replacement of vegetation and wetland functions and values; establish required monitoring procedures and maintenance Page 5 of 16 activities; stage the work over time; require the alteration of the site design to ensure buffering; and/or require the provision of a performance security. (b). Any projects seeking a wetland alteration permit subject to this ordinance will be required to submit the following: (1). A wetland alteration permit application (2). A site/grading plan of the entire property (3). Existing and proposed drainage areas to wetlands (4). A wetland delineation report in accordance with section 20-405 (5). Wetland classification information in accordance with section 20-406 for each wetland on property (6). Buffer strip plan meeting the criteria of section 20-411 (c) and (d) (7). Submittals required by the Wetland Conservation Act (8). Topographic data (9). Other information as required by the city (c). Decisions made under this ordinance that fall under the authority of the Minnesota Wetland Conservation Act may be appealed to the Minnesota Board of Water and Soil Resources under Minnesota Rules 8420.0250, after administration appeal rights under the official controls have been exhausted. Staff costs to the city associated with appeals shall be borne by the applicant. (d). The city council shall appoint a person to serve on a technical evaluation panel. The person must be a technical professional with expertise in water resources management. Decisions under this ordinance must not be made until after receiving the determination of the technical evaluation panel regarding wetland public values, location, size, and/or type if the city council, the landowner, or a member of the technical evaluation panel asks for such determinations. This requirement does not apply to wetlands for which such data is included in an approved comprehensive wetland management plan per Minnesota Rules 8420.0240. The city council may seek and consider recommendations, if any, made by the technical evaluation panel in making replacement plan decisions. Unless otherwise designated, the city's representative on the technical evaluation panel shall be the WCA agent. (e). The applicant for a wetland alteration permit is responsible for obtaining all other necessary permits including but not limited to those required by watershed districts, Minnesota Department of Natural Resources, United States Army Corps of Engineers and Minnesota Pollution Control Agency prior to commencement of the permitted work. Sec.20-410. General standards. (a). The following standards apply to all lands within and abutting a wetland: (1). Septic and soil absorption system must be a setback minimum of 75 feet from the ordinary high water mark of the wetland. Page 6 of 16 (2). The lowest ground floor elevation of a principal structure is three feet above the 100-year flood elevation of the wetland. (3). Access across a wetland shall be by means of a boardwalk or elevated structure and only upon approval of a wetland alteration permit. Wetland crossings must also be in conformance with all other state regulations. (4). Docks and boardwalks shall be elevated a minimum of six inches above the ordinary high water mark. Docks and boardwalks shall only be permitted to cross wetlands in instances where a wetland is riparian to a lake. (5). The erosion and sediment control goals and policies within the city's Surface Water Management Plan shall be met. (6). Stormwater runoff shall not be discharged into wetlands without water quality pretreatment as prescribed by Chanhassen City Code. (b). When a wetland alteration permit is issued allowing wetland alteration, the following standards shall be followed: (1). The alteration will not have a net adverse effect on the ecological and hydrological characteristics of remaining wetland. (2). It shall be located as to minimize the impact on vegetation. (3). It shall not adversely change water flow. (4). The size of the altered area shall be limited to the minimum required for the proposed action. (5). The disposal of any excess material is prohibited within remaining wetland areas. (6). The disposal of any excess material shall include proper erosion control and nutrient retention measures. (7). Alterations to any wetland area are prohibited during waterfowl breeding season or fish spawning season, unless it is determined by the city that the wetland is not used for waterfowl breeding or fish spawning. (8). Alterations to wetland areas shall be mitigated in accordance with the requirements of this ordinance if the activity results in a loss of wetland area and/or function and value of the wetland. (9). Dedicated buffers in accordance with section 20-411. Sec. 20-411. Placement of structures. (a). For lots created on or after a buffer strip shall be maintained abutting all wetlands. All existing vegetation adjacent to a wetland shall be left undisturbed and applied toward the buffer strip unless otherwise approved by the WCA agent or city council. Buffer strip vegetation shall be established and maintained in accordance with the following requirements. If the buffer strip is disturbed, native plant species shall be selected from wetland and upland plants to Page 7 of 16 provide diverse habitat for various species of wildlife. Buffer strips shall be identified by permanent monumentation acceptable to the city. A minimum of one wetland buffer monument is required per lot abutting the wetland edge. The maximum spacing between monuments is 300 feet. (b). The following table provides the minimum standards required for each wetland classification. Structure Setback Permanent Buffer Percent of Buffer Wetland from Buffer Edge Strip Minimum Strip in Native Classification (feet) Width (feet) Vegetation Preserve 50 50 100% Manage 1 40 30 100% Manage 2 40 25 Over 50% Manage 3 40 20 Over 50 % MANAGE SWETLAND ILLUSTRATION BUFFER I I I S1'IEE I :n. W~/W I I I I I I I O. EAS (c). For lots of record prior to the minimum buffer strip and setback requirements shall comply with subparagraph (b) above. If buffer strips and setbacks were approved as part of the subdivision, those standards shall prevail, except that in no case shall structures be set back less than 40 feet from the wetland edge. Page 8 of 16 (d). The Planning Commission or City Council may approve variances from applicable buffer strips and setback requirements if suitable hardship can be demonstrated. In these instances, additional performance standards may be enforced to compensate for the reduced buffer strip widths or setbacks. (e). In addition to the requirements above, wetland buffer strips for wetland mitigation areas and those counted as Public Value Credit (PVC) shall also conform to the minimum standards as set forth by the Wetland Conservation Act. (0. No structures are to be placed within the wetland setback. (g). For any subdivision, the locations of buffer strips and wetland setbacks shall be surveyed and recorded on the Property Title and Certificate of Survey. A Certificate of Occupancy shall not be issued unless this task is completed and approved by City staff. (h). Retaining walls may be located within wetland setbacks, but neither the walls nor the land alteration that takes place as part of wall construction shall encroach into the required buffer strips. Sec. 20-412. Buffer strips required. (a). Before release of final plat, the applicant must submit to the WCA agent a drainage and utility easement for protection of the wetland and approved buffer strip. The easement must describe the boundaries of the wetland and the wetland buffer strips (b). Building structures, paving, mowing, introducing non-native vegetation, cutting, filling, dumping, disposing of yard waste, fertilizing, or tampering with the monuments within buffer strips is prohibited. (c). Additional wetland impacts shall not be allowed for the creation of buffer strips. (d). The use of meandering buffer strips to maintain a natural appearance is encouraged (e). Where roadways are constructed next to a wetland, a buffer strip shall be maintained. (0. Where acceptable natural vegetation exists in a wetland and adjacent buffer strip, the retention of such vegetation in an undisturbed state shall be required unless the applicant receives approval to replace such vegetation. A wetland and/or buffer strip has acceptable vegetation if it is dominated by native tree, shrub, or grass species, and has not been used for agricultural production in the last five years. Page 9 of 16 (g). The WCA agent may deny the use of existing vegetation for the use of buffer strips if: 1. It is dominated by any species on the state noxious weed list as defined by Minnesota Statutes, Section 18.76-18.88. These species include species such as leafy spurge, spotted knapweed, purple loosestrife, and common and glossy buckthorn; 2. It is present on unstable slopes, has significant bare soil, displays a history of erosion problems, is prone to gully formation, or does not function for sediment and nutrient removal; 3. Any areas were used for agricultural production in the last five years; or 4. The buffer strip is disturbed or altered. (h). If an area is deemed to be unacceptable in its current state, wetland buffer landscaping plan must be submitted to the WCA agent. This plan shall include at a minimum: 1. A plan sheet showing the proposed new buffer strip locations and any buffer strips acceptable as existing. Existing buffer strips shall be identified and marked to prevent accidental disturbances. 2. A specification as to what seed mixture will be used, or what trees and/or shrubs will be planted and their locations. 3. A verification that all seed stock and tree species are native to Minnesota and are of local ecotypes. 4. A detailed specification that identifies the project schedule, materials, installation or seeding instructions, and costs. 5. A maintenance schedule that describes the activities that will occur for at least the first two (2) years. This should include a schedule of mowing and spot spraying for weeds if an area is seeded. Plans that call for periodic burning shall have additional details and must have special permission prior to installation. 6. A detail of all Best Management Practices (BMPs) and erosion control plans. 7. A plan identifying the locations of buffer strip markers. 8. An electronic copy of plans in a format compatible with the City GIS database. (i). The city may, at their discretion, require a cash escrow or letter of credit up to 110% of the cost to reestablish the buffer strip should it not be successful, not be maintained, or otherwise require city intervention to maintain the ordinance requirements. Sec. 20-413. Wetland alteration. (a). An applicant for a wetland alteration permit must demonstrate that the activity impacting a wetland has complied or, through imposition of conditions of approval, will comply with all of the requirements of the Wetland Conservation Act. Page 10 of 16 (b). A wetland alteration permit shall not be issued unless the proposed development complies with this article. (c). When a wetland alteration permit is issued allowing wetland alteration, the alteration must be consistent with the city's Surface Water Management Plan and the Wetland Conservation Act. The alteration shall not alter the hydrological patterns in the remainder of the wetland, if a portion of the wetland remains, unless exempted under section 20-417. Sec. 20-414. Wetland management activities. Prior to commencement of a wetland management activity, an administrative wetland permit must be obtained for the activity in accordance with section 20-415. Sec. 20-415. Administrative wetland permit. (a). Applications for administrative wetland permits shall be made on a form supplied by the city. A fee shall be paid as set forth in Chanhassen City Code. The WCA agent shall review applications to ensure proposed activities are in compliance with the Wetland Conservation Act and the requirements of this ordinance and are consistent with approved and/or accepted wetland management practices. (b). Activities for which administrative wetland permits are approved shall not contribute to nuisances as defined in the Chanhassen City Code. Sec. 20-416. Mitigation. (a). Mitigation intent. Where a wetland alteration permit is approved and mitigation is required pursuant to City Code and the Wetland Conservation Act, mitigation must result in an improvement to the wetland function and value. Mitigation plans must address water quality, improvement, and maintenance of preexisting hydrological balance and wildlife habitat. The wetland function and value will include improvement of water quality, maintaining hydrological balance, and provision of wildlife habitat. Mitigation will be performed at ratios required by the Minnesota Wetland Conservation Act to achieve replacement of the wetland function and value. (b). Mitigation standards. The functions and values of mitigation wetlands shall be achieved through wetland restoration, creation and/or enhancement. The mitigation standards found in Minnesota Rules 8420.0550 shall be followed. (1). Mitigation shall be subject to wetland setback and buffer strip requirements as set forth in this ordinance. Page 11 of 16 (2). Mitigation shall at a minimum replace preexisting wetland function and values through the ratios set forth in Minnesota Rules 8420.0541. (3). Mitigation, through the buffer strip, shall provide landscaping for nesting and food for wildlife habitat. The buffer strip shall provide for wildlife cover and utilize a diversity of native flora (i.e., trees, shrubs, grasses, herbaceous plants) to encourage wildlife diversity and provide visual variety. (4). Wetland mitigation shall be undertaken on-site. If this is not feasible, then mitigation may occur locally within the subwatershed. If this is not possible, then mitigation ,au occur outside the subwatershed, elsewhere in the city. If mitigation cannot be accomplished on site, or if the city deems it necessary to perform mitigation off-site, then the applicant shall be responsible for providing off-site mitigation within the major subwatershed, as designated by the Minnesota Wetland Conservation Act, or purchasing wetland credits from the state wetland bank. (d). Construction management and long term wetland maintenance. (1). The wetland alteration permit holder shall follow best management practices to minimize direct impacts due to erosion and construction practices and to safeguard wildlife habitat. (2). The wetland alteration permit holder shall submit an annual report to the city for replacement wetlands in Chanhassen. The purpose of the annual report is to describe actual wetland management, restoration or creation activities completed during the past year as well as activities planned for the upcoming year. The annual report shall include all the information required of annual monitoring reports by Minnesota Rules 8420.0620 subpart 2. The wetland alteration permit holder shall submit annual monitoring reports as required by Minnesota Rules 8420.0610. Submission shall continue for five years or until the replacement wetland is deemed by the Technical Evaluation Panel (TEP) to be fully functional. Where feasible, the city shall require the wetland alteration permit holder to satisfy long-term management requirements. (e). Mitigation Surety. To ensure that the proposed wetland replacement occurs, the city shall hold either a cash escrow or letter of credit equal to 110% of the current value of wetland credits on the open market. An additional escrow account shall be established to ensure that the required monitoring occurs. The monitoring escrow shall be set at 110% of the current average monitoring expense as performed by an independent consultant. The monitoring and replacement escrows may be released incrementally as monitoring and replacement are successfully completed. The remaining escrow amount will be returned and the letter of credit terminated upon completion of the monitoring and approval by the Technical Evaluation Panel Page 12 of 16 (TEP). Any interest earned by holding of a cash escrow shall be the property of the city. (t'). Within the Minnehaha Creek Watershed District, 1:1 mitigation is required for excavation within wetlands. Sec. 20-417. Exemptions and no loss determinations. (a). Activities exempted by Minnesota Rules 8420.0122 or determined to result in no net loss of wetlands shall be exempted from the provisions of this ordinance. However, certificates of exemption or no loss must be obtained from the city prior to starting work. (b). A person conducting an activity in a wetland under an exemption shall ensure that: (1). Appropriate erosion and sediment control measures are taken to prevent sediment discharges from the site; (2). The activity does not block fish activity in a watercourse; and (3). The activity is conducted in compliance with all other applicable federal, state, and local requirements, including best management practices as listed in part 8420.0112, and water resource protection requirements established under M.S. Ch. 103H. Sec. 20-418. Variances. Variances from the requirements of this ordinance may be granted in accordance with the variance provisions of Article II, Division 3 of this chapter so long as the variances do not violate the Wetland Conservation Act and rules adopted under the Act. Sec. 20-419. Expiration and renewal of permit. (a). Unless otherwise specified by the city council, the permittee shall begin and complete the development authorized by the wetland alteration permit within one year after the date the council approves the permit application. (b). The permittee shall provide written notice to the city 24 hours prior to the commencement and completion of the permitted project. No project shall be deemed to have been completed until approved by the city after receipt of notice of completion. (c). If the permittee fails to commence work within the time specified in this section, the permit shall be void. The permittee may make a written application to the city council for an extension of the time to commence work, but only if the permittee submits the application prior to the date already established to commence work. The application of an extension shall state the reasons the permittee requires an Page 13 of 16 extension. If the council does not extend the permit, the holder of the void permit may apply for a new permit. Sec. 20-420. Inspection of work. The city may cause inspection of work for which a wetland alteration permit is issued, at the applicant's expense, to be made periodically during the course of such work and shall cause final inspection to be made following the completion of the work. Sec. 20-421. Enforcement procedures. (a). Violation of this article, wetland protection, or of the terms of a permit issued thereunder shall be a misdemeanor. (b). Any person who alters a wetland in violation of this article shall apply for a wetland alteration permit and shall pay a filing fee double the regular fee. The city council may require the violator to restore the wetland or take other mitigative measures. Sec. 20-1060. Purpose. (2) Protect creek corridors, wetlands, and significant stands of mature trees through the use of careful site design; protective easements; sensitive alignment and design of roadways and utilities; incorporation of natural featur<:(s; landscaping and massing of trees that enhance existing natural features and views; and the practices delineated in the City's Best Management Practices Handbook Surface Water Management Plan. Sec. 20-1061. Intent. (2) Preservation of the natural conditions found on each site to the greatest extent possible, through minimized removal of trees and other vegetation and soil, minimized site grading, and application of the practices found in the city's Best Management Practices Handbook Surface Water Management Plan. Sec. 20-1072. Landscaping. (a) Where natural or existing topographic patterns contribute to the beauty or utility of a development, they shall be preserved to the greatest extent possible. Modification to topography will be permitted where and to the extent that it contributes to good design. All topographic modifications shall adhere to the practices delineated in the city's Best Mo:nagement Practices Handbook Surface Water Management Plan. Sec. 20-1085. Purpose. Page 14 of 16 (3) Protect creek corridors, wetlands, and significant stands of mature trees through the use of careful site design; protective easements; sensitive alignment and design of roadways/access and utilities; incorporation of natural features; landscaping and massing of trees that enhance existing natural features and views; and the practices delineated in the city's Best Management Practices Handbook Surface Water Management Plan. Sec. 20-1408. Impervious surfaces. Creation of impervious surfaces within the bluff setback may contribute to bluff instability due to increased runoff and/or erosion. Impervious surfaces are prohibited within the bluff setback unless specifically authorized within this article. Sec. 20-1551. Purpose. (a) Protect the Bluff Creek Corridor, wetlands, bluffs, and significant stands of mature trees through the use of careful site design, protective covenants, sensitive alignment and design of roadways and utilities, incorporation of natural features, landscaping, techniques outlined in the city's surface water management plan, and the practices delineated in the city's Best Management Practices Handbook Surface Water Management Plan. Sec. 20-1552. Intent. (b) Preservation of the natural conditions found in the primary zone and to the greatest extent possible, preserving significant resources and minimizing impacts in the secondary zone through cluster development and other practices which minimize the removal of vegetation, minimize site grading, and application of practices found in the city's Best Management Practices Handbook Surface Water Management Plan. Sec. 20-1556. Impervious cover and slopes. To the greatest extent possible, all development shall minimize the amount of impervious surface by clustering development, using common access drives and utility corridors and minimizing building footprint size. Roads, walkways, bike trails, and parking areas must be designed parallel to natural contours with consideration to maintaining consolidated areas of natural topography and vegetation. Management of surface run-off caused by impervious cover shall be designed using practices delineated in the city's Best Management Practices Handbook Surface Water Management Plan. Within the secondary zone of the BCO District, areas with average slopes exceeding 25 percent shall be preserved in their natural state and maintained as permanent open space. Areas with average slopes less than 25 percent but greater than ten percent shall not exceed an impervious surface coverage of 25 percent. Impervious coverage for areas Page 15 of 16 where average slopes are less than ten percent shall be governed by the underlying zoning district. Sec. 20-1561. Natural habitat preservation. (b) Where possible, any disturbances of natural habitat areas within the secondary zone shall be avoided. Any alterations to the natural habitat within the secondary zone shall adhere to the practices delineated in the city's Best Management Prnctices Handbook Surface Water Management Plan. Page 16 of 16 LENNAR (JlJllhn LJJ1l1 lnlt'l:ru. December 28, 2006 City of Chanhassen Lori Haak, Water Resources Coordinator 7700 Market Boulevard Post Office Box 147 Chanhassen MN, 55317 Re: Code Revisions Resulting from Adoption of Second Generation SWMP Dear Ms. Haak: Thank you for including Lennar in this code review process and inviting comments. Clearly, a significant amount of effort has been invested in the Second Generation Surface Water Management Plan (SWMP) and the proposed code revisions to further enable this plan to be implemented. White many of the code revisions appear to be reasonable, we are particularly concerned about the proposed language in the sections outlined below. In short, our primary concerns are (1) the overly aggressive buffer strip width and buffer setback language; and (2) the overly restrictive interpretation of impervious surface. Chapter ~ Section 1-2, Impervious surface definitions: The proposed definition is overly restrictive and does not include exemptions that are commonly accepted in Chanhassen's peer cities. Pavers, stepping stones, semi-pervious block, and related materials should be included as exceptions to the impervious surface calculations. Please note that our opinion on this matter as articulated in a letter to Mr. TQdd Gerhardt dated January 6, 2006 has not changed. Section 1-2, WeUand definitions: Creating wetland definitions that are unique to the City of Chanhassen unnecessarily complicates wetland management. 00 the City's wetland definitions supercede the classifications that result from the MnRAM analysis? What is the operational relationship between the City's definitions and the established classification system? We are concerned that the classification standardS and criteria are too vague and subject to interpretation. Chapter .19 Section 19-102-(a)(6), Concrete washout areas: Temporary concrete washout areas that are in compliance with the City's engineering standards should be specifically noted as an exception. If this section is re-written as subsequently proposed on 12/28/06, does the phrase "or other lawfUlly established waste disposal facility" in Section 19-102(a} include temporary concrete washout facilities that are incompliance with the Oty'seilgineering standards? 5ection 19-143 (eX1), LID: This section implies that Low Impact Development (UD) practices such as swales and natural infiltration areas are encouraged. However, other Section 19 elements describe NURP and other ponding standards. How are proposed UD improvements acknowledged in the calculation of pOnding requirements? How are developers given aedit for including UD practices? This section implies that NURP standards must be met with or without the added functionality of UD improvements. 935 East Wayzata Boulevard, Wayzata, MN 55391 . Phone 952.473.1231 . Fax 952.473.7401 · www.lennar.com !5l-- --== i i i I I . Chapter 20 SecUon 2()-411(b), New buffer requirements: The new buffer requirements are overly restrictive and may be interpreted as .a taking when applied to specific development proposals. What evidence is there that a 50 foot buffer provides tangible improvements to wetland quality relative to a buffer of 30 feet or less? Assuming that a higher priority Is placed on the buffer strip over the structure setback, then the proposed structure setback should be significantly reduced if the buffer strip widths are adopted In their current form. We support reinstating the language permitting an average buffer width to provide more flexibility in applying this standard. Section 2()-411(d), Vatiances: Will the standard variance standards be applied when considering a variance from the proposed buffer standards, or will different standards be utilized? We anticipate that applying these standards along with the City's other standards for streets, sum.ce water management (ponds), maximum slopes and tree preservation will likely generate many variance requests, especially on smaller sites. These setbacks will also make it more difficult for development or redevelopment on some parcels to reach density requirements in the Comprehensive Plan. Section 2()-411(g), Setbacks on SUtveys: The wetland setbacks should not be required to be Included on title and Certificate of Survey since the wetland setbacks are subject to change over time. If the setbacks were tD be increased at some unknown future time and a Certificate of Survey is produced with the less restrictive setback, th~ City may be In a position to honor the outdated setback as stated on the Certificate of Survey. Moreover, this section duplicates the proposed requirements in Section 20-412(a) to place buffer strips within drainage and utility easements. Section 2()-411(h), Retaining walls: Retaining walls and limited land alteration should be permitted within the buffer strip, especially In situations where the buffer is being created rather than preserved. If the buffer strips had a narrower minimum width (such as 20 feet for the Preserve classification), we would likely not object to this proposed requirement In addition, variance langauge should be added similar to the language in Section 20-411(d). Section 20-416(d)(2), Reporting requirements: In the first paragraph, restrict the period of time that a report is requiied. For example, link the required number of reports to the growing seasons In which the wetland alteration will occur. Moreover, state that an annual report Is not required if no active management actMties are planned. The second paragraph appears to require monitoring reports for five years once the alterations or new construction are complete. Our concern is that the current proposed language might be interpreted to require submittal of annual reports beyond the five-year time limit proposed. We appreciate the opportunity to comment, and we look forward to continuing to partidpate in this process. Some of the proposed rules are overty aggressive and inconsistent with Chanhassen's peers. This approach significantly impacts priVate landowners and developers by placing additional restrictions and limitations as to how land is utilized. This inequitable burden could be lessened if a more flexible, performance-based approach were adopted to enable reasonable deviations from the proposed standards. Respectfully submitted, flt~ ~w\> Matt Goldstein, AICP Project Manager Lennar Corporation LUNDGREN \ /11'1/(/1 (O'It!lt,i'11 January 6, 2006 City of Chanhassen Todd Gerhardt City Manager P.O. Box 147 Chanhassen, MN 55317 Re: Impervious Surface Regulations Dear Mr. Gerhardt: With this letter the Lennar Family of Builders including Lundgren and Orrin Thompson endeavors to encourage discussion about the City's codes that relate to impervious surface. In short, Chanhassen's impervious surface requirements are overly restrictive and negatively impact our ability to meet our buyers' needs. These regulations may be changed to permit slightly more area on single family homesites to be covered in a manner that remains consistent with the City's guiding policy documents. Following the present course is negatively affecting the City's tax base by softening demand for higher-end single family homes in an increasingly competitive market segment. The characteristics of our best-selling, higher-end single family homes in Chanhassen are changing quickly. Chanhassen buyers are increasingly interested in larger homes that include four-stall garages, larger kitchens, and patios and decks that are functional for entertaining. After the purchase, buyers want the flexibility of being able to expand their home, improve their homesite, or add other amenities such as pools, hot tubs and athletic courts in the future. The current impervious surface regulations impede this future flexibility and limit our ability to meet our buyers' needs. First, the City Code does not currently provide credit for using some of the imperviOUS mitigation solutions that have been embraced by other Twin Cities communities and watershed districts. For example, the use of rain gardens, rain barrels, individual below-grade surface water storage systems, and pervious block are not permitted to be credited against the effective covered area of a single family homesite. Enhancing the code with the use of flexible, performance-based impervious mitigation techniques would provide more methods to address impervious concerns. Second, Chanhassen's maximum lot coverage of 25% is the lowest maximum that we've encountered in the western suburbs in the recent past. In nearby communities, 30% is quite common as the standard maximum (without a PUD). This difference caused a concern in Settlers West that was solved by taking area from a Chanhassen outlot bordering Eden Prairie and adding that area to the adjacent homesite to create enough buildable square footage so a similar home could be built immediately next to its Eden Prairie neighbor. Third, impervious surface is measured twice in the case of private streets with segments on private homesites thereby falsely decreasing the effective buildable area of homesltes that include private street segments. In Pinehurst, for example, ponds were sized based upon surface water management calculations that included runoff generated by both the public and the private streets. However, the "buildable" area of homesites that include portions of the private streets is reduced by that pavement area. This is duplicative. Fourh, regarding open space, the infiltration function of undisturbed open space is not acknowledged in the Code. In Pinehurst, there was no surface water credit given to the dedication of the 2.9-acre Outlot A, even though a portion of the surface water drains to this parcel. 5545 Indian Mound East, Wayzata, MN 55391- Telephone: 952-473-1231- Fax: 952-473~7401 - www.lundgrentc.com . Thoughtfully regulating residential development is an iterative and dynamic process. We request that the existing Impervious surface regulations and policies be updated to permit the use of proven creative on-site impervious mitigation techniques and rectify potential redundancies. This may be done in a manner that preserves the desired low-density neighborhood character, addresses site constraints such as poorly drained soils, and respects existing site amenities such as preserved trees. I appreciate the discussions I have had with staff recently regarding this issue, and I understand staffs' position on these matters. I continue to believe that this Is a significant policy Issue for the City of Chanhassen and I welcome the opportunity to raise this matter with the City Council. We strive to build the best homes in the Twin Cities and in our experience these impervious surface regulations significantly impair our ability to deliver the high-quality homes Chanhassen has become known for. Respectfully submitted, /n~ ~-- I,.- Matt Goldstein, AICP CITY OF CHANHASSEN 7700 Market Boulevard PO Box 147 Chanhassen, MN 55317 Administration Phone: 952.227.1100 Fax: 952.227.1110 Building Inspections Phone: 952.227.1180 Fax: 952.227.1190 Engineering Phone: 952.227.1160 Fax: 952.227.1170 Finance Phone: 952.227.1140 Fax: 952.227.1110 Park & Recreation Phone: 952.227.1120 Fax: 952.227.1110 Recreation Center 2310 Coulter Boulevard Phone: 952.227.1400 Fax: 952.227.1404 Planning & Natural Resources Phone: 952.227.1130 Fax: 952.227.1110 Public Works 1591 Park Road Phone: 952.227.1300 Fax: 952.227.1310 Senior Center Phone: 952.227.1125 Fax: 952.227.1110 Web Site www.ci.chanhassen.mn.us December 29, 2006 Matt Goldstein Project Manager Lennar Corporation 935 East Wayzata Boulevard Wayzata, MN 55391 Re: Comments Regarding Proposed Code Revisions Dear Matt: Thank you for your thoughtful and thorough comments regarding the proposed changes to the Chanhassen City Code. It is my pleasure to provide responses on behalf of the City to your comments. Your comments and these responses will be included in their entirety in the staff report that will appear before the Chanhassen City Council on January 8, CHAPTER 1 Comment: Sit definition is 0 commonly ac semi-pervious to the impervi matter as artic~ has not changed: Response: 'I' The propoie~ however, it dde~); been interpretedH' interpretation a.! Communitie~t '. with sev. impervf' "impervio proposed de ........ It should be ri01:~c> ." .... .. surfaces are allowedar1a)~~~~;.. towards lot coverage is not'" The City of Chanhassen - A growing community with clean lakes, quality schools, a charming downtown, thriving businesses, winding trails, and beautiful parks. A great place to live, work, and play. December 29, 2006 Page 2 of 5 Comment: Section 1-2, Wetland definitions: Creating wetland definitions that are unique to the City of Chanhassen unnecessarily complicates wetland management. Do the City's wetland definitions supersede the classifications that result from the MnRAM analysis? What is the operational relationship between the City's definitions and the established classification system? We are concerned that the classification standards and criteria are too vague and subject to interpretation. Response: The classifications were developed as a result of the Minnesota Board of Water and Soil Resources (BWSR) refining the Minnesota Routine Assessment Method (MnRAM). The proposed classifications are linked directly to the outcomes of MnRAM, which is a peer-reviewed and state-accepted method of wetland assessment. The existing classifications (Pristine, Natural, Ag/Urban) were established in the early 1990s by the consultants working on the original Surface Water Management Plan and are therefore more subjective. CHAPTER 19 Comment: Section 19-102-(a)(6), Concrete washout areas: Temporary concrete washout areas that are in compliance with the City's engineering standards should be specifically noted as an exception. If this section is re-written as subsequently proposed on 12/28/06, does the phrase "or other lawfully established waste disposal facility" in Section 19-1 02( a) include temporary cpncrete washout facilities that are in compliance with' the City's engineering standards? Response: (The first citation refers to a draft version of the proposed rules that has since been revised.) Any waste disposal Best Management Practice (BMP) that is established and operated in compliance with the City's standards and/or NPDES Phase II Construction Site Permit requirements would constitute a "lawfully established waste disposal facility." This would include properly constructed and utilized concrete washout facilities. Comment: Section 19-143 (C)( 1), LID: This section implies that Low Impact Development (LID) practices such as swales and natural infiltration areas are encouraged. However, other Section 19 elements describe NURP and other ponding standards. How are proposed LID improvements acknowledged in the calculation of ponding requirements? How are developers given credit for including LID practices? This section implies that NURP standards must be met with or without the added functionality of LID improvements. Response: The City encourages LID practices, but does not mandate them. Many LID BMPs result in a reduction in impervious surface or an increased time of concentration over traditional development. This can be reflected in weighted curve numbers or through accepted modeling methods. Due to the tight soils within Chanhassen, implementing infiltration can be difficult. In modeling infiltration, if the developer's engineer submits HydroCAD calculations, the runoff to a pond could be reduced through the exfiltration function; however, the soil type used for modeling must match the soil type listed December 29, 2006 Page 3 of 5 in the Carver County Soil Survey. The exception to this would be if the developer's engineer submits soil borings that indicate that the soils differ from the soils shown in the soil survey. CHAPTER 20 Comment: Section 20-41l(b), New buffer requirements: The new buffer requirements are overly restrictive and may be interpreted as a taking when applied to specific development proposals. What evidence is there that a 50 foot buffer provides tangible improvements to wetland quality relative to a buffer of 30 feet or less? Assuming that a higher priority is placed on the buffer strip over the structure setback, then the proposed structure setback should be significantly reduced if the buffer strip widths are adopted in theircurrentform. We support reinstating the language permitting an average buffer width to provide more flexibility in applying this standard. Response: The proposed buffer requirements are less than or equal to the minimum recommended widths set forth in the Wetland Management Classification System that was designed to accompany MnRAM. Scientific literature maintains that 50 feet is the absolute minimum buffer width for wildlife habitat. Additionally, a literature review has indicated that "buffer widths of 50 feet generally will provide adequate protection from suspended solids for maintaining high water quality." Around the City's most sensitive water resources, it is reasonable to expect that this level of protection be required. No changes are proposed to the required setbacks. The intent of the setbacks is to provide a useable area for property owners adjacent to wetlands. This minimizes the potential for future encroachment into buffer areas. Average buffer widths have been eliminated because they are difficult to administer as permits are issued for individual lots. Additionally, it is confusing for property owners if the standard is not consistent around the entire basin. Buffer and setback requirements for existing lots would not change. The proposed changes would only apply to lots created after the date of codification. Comment: Section 20-41l(d), Variances: Will the standard variance standards be applied when considering a variance from the proposed buffer standards, or will different standards be utilized? We anticipate that applying these standards along with the City's other standards for streets, surface water management (ponds), maximum slopes and tree preservation will likely generate many variance requests, especially on smaller sites. These setbacks will also make it more difficult for development or redevelopment on some parcels to reach density requirements in the Comprehensive Plan. Response: The part of the code addressing variances (Section 20-56 through 20- 60) would apply to these variances. It is difficult to predict any increase in the number or magnitude of variance requests that may occur. However, City staff encourages developers to communicate with the City early in the land December 29, 2006 Page 4 of 5 acquisition/preliminary site design process so that a reasonable assessment of the capabilities of properties can be made. Comment: Section 20-411(g), Setbacks on surveys: The wetland setbacks should not be required to be included on title and Certificate of Survey since the wetland setbacks are subject to change over time. If the setbacks were to be increased at some unknown future time and a Certificate of Survey is produced with the less restrictive setback, the City may be in a position to honor the outdated setback as stated on the Certificate of Survey. Moreover, this section duplicates the proposed requirements in Section 20-412(a) to place buffer strips within drainage and utility easements. Response: Wetland setbacks on existing lots are not subject to change over time, unless additional subdivision takes place. This requirement is not duplicative because it is more precise than the drainage and utility easement requirement. Including the buffer and setback on the title and Certificate of Survey discloses that a buffer and setback are required on the lot and demonstrates the extent of any wetland-related restrictions. This will help property owners to be more informed about encumbrances on their lots. Comment: Section 20-411 (h), Retaining walls: Retaining walls and limited land alteration should be permitted within the buffer strip, especially in situations where the buffer is being created rather than preserved. If the buffer strips had a narrower minimum width (such as 20 feet for the Preserve classification), we would likely not object to this proposed requirement. In addition, variance language should be added similar to the language in Section 20-411 (d). Response: Current City Code does not allow placement of retaining walls within wetland setbacks. Staff recognizes that this is unrealistic based on the topography of Chanhassen, so language permitting retaining walls within wetland setbacks is proposed. Buffer strips should be maintained at the base of retaining walls to ensure that the runoff from the walls is buffered before entering the wetland. The variance language in 20-411 (d) applies throughout this part. Comment: Section 20-416(d)(2), Reporting requirements: In the first paragraph, restrict the period of time that a report is required. For example, link the required number of reports to the growing seasons in which the wetland alteration will occur. Moreover, state that an annual report is not required if no active management activities are planned. The second paragraph appears to require monitoring reports for five years once the alterations or new construction are complete. Our concern is that the current proposed language might be interpreted to require submittal of annual reports beyond the five-year time limit proposed. Response: The reporting requirements proposed here are consistent with the requirements of the Wetland Conservation Act, which does require additional monitoring beyond five years if the Technical Evaluation Panel (TEP) has not accepted the mitigation area. The proposed language, while potentially extending the five-year monitoring term, could also shorten the monitoring term if the TEP accepts the mitigation area before the five-year monitoring term is complete~ December 29, 2006 Page 5 of 5 Once again, thank you for your comments. I encourage you to remain informed and involved as the City begins nondegradation assessment and planning, as required by its NPDES Phase II MS4 Permit. Additional code revisions may occur as a result of that process, since the City will be required to achieve or move toward 1988 levels of total phosphorus, total suspended solids and volume. Feel free to contact me at 952.227.1135 or lhaak@ci.chanhassen.mn.us if you have additional questions regarding the proposed code revisions or future surface water issues. Regards, ,~~.,- Lori Haak Water Resources Coordinator CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA SUMMARY OF ORDINANCE NO._, AN ORDINANCE AMENDING CHAPTER 1 OF THE CHANHASSEN CITY CODE GENERAL PROVISIONS. The purpose of this code amendment is to revise and update Section 1-2 of the City of Chanhassen including: . Adding definitions that appear in the Second Generation Surface Water Management Plan, including: Administrative Wetland Permit; Boardwalk; City Wetland Inventory; Erosion Control; GIS; Hardcover; Manage 1 Wetland; Manage 2 Wetland; Manage 3 Wetland; Minnesota Routine Assessment Method; MPCA; NPDES permit; Preserve Wetlands; Sediment Control; Storm Water Pollution Prevention Plan; Surface Water Management Plan; WCA agent; Wetland Conservation Act; Wetland alteration; and Wetland management activity. . Removing terms that are no longer used or referenced in the Second Generation Surface Water Management Plan, including: Ag/Urban wetlands; Natural wetlands; Pristine wetlands; Utilized water body; Water body, utilized; Wetlands, ag/urban; Wetlands, natural; and Wetlands, pristine. . Amending the definition for impervious surface to clarify materials and surfaces considered . . ImpervIOUS. A printed copy of Ordinance No. _ is available for inspection by any person during regular office hours at the office of the City Manager/Clerk. PASSED, ADOPTED, AND APPROVED FOR PUBLICATION this _ day of 2007, by the City Council of the City of Chanhassen. CITY OF CHANHASSEN BY: Thomas A. Furlong, Mayor AND: Todd Gerhardt, City Manager/Clerk (Published in the Chanhassen Villager on ). CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA SUMMARY OF ORDINANCE NO._, AN ORDINANCE AMENDING CHAPTER 18 OF THE CHANHASSEN CITY CODE SUBDIVISIONS. The purpose of this code amendment is to revise and update the zoning code of the City of Chanhassen including: . Removing the requirement for replacement of four inches of topsoil in disturbed areas . Replacing the phrase "Best Management Practices Handbook" with "Surface Water Management Plan" . Updating the reference from the February 1994 Surface Water Management Plan to the August 2006 Surface Water Management Plan . Including a reference to subpart (c) 3 of Section 4-30 where the water quality and water quantity connection charges are set A printed copy of Ordinance No. _ is available for inspection by any person during regular office hours at the office of the City Manager/Clerk. PASSED, ADOPTED, AND APPROVED FOR PUBLICATION this _ day of 2007, by the City Council of the City of Chanhassen. CITY OF CHANHASSEN BY: Thomas A. Furlong, Mayor AND: Todd Gerhardt, City Manager/Clerk (Published in the Chanhassen Villager on ). cITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA SUMMARY OF ORDINANCE NO._, AN ORDINANCE AMENDING CHAPTER 19 OF THE CHANHASSEN CITY CODE WATER, SEWERS AND SEWAGE DISPOSAL The purpose of this code amendment is to revise and update the water, sewers and sewage disposal code of the City of Chanhassen including: . Prohibiting unlawful discharges to storm sewers . Restructuring the surface water management article . Incorporating the city's development standards into the surface water management article . Requiring landlocked storm water basins to hold back-to-back 100-year rain events . Requiring additional storm water management techniques within the Assumption Creek subwatershed to mitigate impacts of development to that resource A printed copy of Ordinance No. _ is available for inspection by any person during regular office hours at the office of the City Manager/Clerk. PASSED, ADOPTED, AND APPROVED FOR PUBLICATION this _ day of 2007, by the City Council of the City of Chanhassen. CITY OF CHANHASSEN BY: Thomas A. Furlong, Mayor AND: Todd Gerhardt, City Manager/Clerk (Published in the Chanhassen Villager on ). CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA SUMMARY OF ORDINANCE NO._, AN ORDINANCE AMENDING CHAPTER 20 OF THE CHANHASSEN CITY CODE ZONING. The purpose of this code amendment is to revise and update the zoning code of the City of Chanhassen including: . Restructuring the wetland protection article . Establishing a City Wetland Inventory . Establishing four management categories for wetlands . Implementing requirements for wetland delineations and their submittals . Defining the procedures for conducting function and value assessments for unclassified wetlands . Requiring notification of the City prior to treatment of wetlands to control nuisance vegetation . Outlining information that must be submitted with a wetland alteration permit application . Setting forth standards for issuance of a wetland alteration permit . Revising the required wetland buffer strips and setbacks for lots created after the codification of this ordinance . Requiring wetland buffer strips and setbacks to be shown on lot surveys . Outlining requirements for wetland buffer strips . Establishing an administrative wetland permit for wetland management activities . Replacing the phrase "Best Management Practices Handbook" with "Surface Water Management Plan" . Prohibiting impervious surfaces within the bluff setback unless otherwise authorized A printed copy of Ordinance No. _ is available for inspection by any person during regular office hours at the office of the City Manager/Clerk. PASSED, ADOPTED, AND APPROVED FOR PUBLICATION this _ day of 2007, by the City Council of the City of Chanhassen. CITY OF CHANHASSEN BY: Thomas A. Furlong, Mayor AND: Todd Gerhardt, City Manager/Clerk (Published in the Chanhassen Villager on ) CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA ORDINANCE NO. AN ORDINANCE AMENDING CHAPTER 1 CHANHASSEN CITY CODE, GENERAL PROVISIONS THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS: Section 1. The following terms within Section 1-2 of the City Code, City of Chanhassen, Minnesota and their definitions, are hereby repealed: Ag/Urban wetlands. Natural wetlands. Pristine wetlands. Utilized water body. Water body, utilized. Wetlands, ag/urban. Wetlands, natural. Wetlands, pristine. Section 2. The definition of "Impervious surface" within Section 1-2 of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: Impervious surface means any material that reduces or eliminates water infiltration when compared to local native soil surface and structure. Impervious surfaces include, but are not limited to: bituminous and concrete driveways, pavers of all material, compacted aggregate, non- porous landscape underlayment, retaining walls, buildings, rooftops, patios, landscape stepping stones or flagstones, driveways, pool decking and any other structures. Exemptions include decks when installed without impervious surface below, landscape rock or mulch with pervious underlayment. Section 3. Section 1-2 of the City Code, City of Chanhassen, Minnesota, is hereby amended to include the following terms and their definitions: Administrative Wetland Permit means authorization to perform an activity that is classified as a Wetland Management Activity. Securing an Administrative Wetland Permit does not exempt the 1 permittee from obtaining any and all other necessary permits (e.g., United States Army Corps of Engineers, Minnesota Pollution Controi Agency). (20) Boardwalk means a linear structure extending across wetlands or lakes that is not supported by posts or poles, but floats or rests upon floats without causing detrimental impacts to the wetland or lake. (20) City Wetland Inventory means the official City Wetland Inventory Map depicting the approximate location and extent of wetlands within Chanhassen. A copy of this map shall be maintained on the City's GIS database, with both hard and electronic copies being made available for public review upon request. (20) Erosion control means best management practices employed to prevent erosion including, but not limited to: soil stabilization practices, limited grading, mulch, temporary or permanent cover, and construction phasing as defined in the MPCA General Construction Permit. (7, 19) GIS means Geographic Information System, such as Arc View. (20) Hardcover see Impervious surface. Manage 1 wetlands means high-quality wetlands that should be protected from development and other pressures of increased use, including indirect effects of development. Maintaining natural buffers will help to retain the significant function these wetlands provide. In the event that impacts to these wetlands cannot be avoided, replacement ratios for mitigation should exceed the state-required minimums. (20) Manage 2 wetlands means wetlands that provide medium functional levels and the wetland extent should be maintained. These wetlands often provide optimal restoration opportunity. (20) Manage 3 wetlands means wetlands that have been substantially disturbed and have the lowest functions and values. (20) Minnesota Routine Assessment Method (or MnRAM) means Minnesota Routine Assessment Method for Evaluating Wetland Functions (MnRAM Version 3.0), or future versions. (20) MPCA means the Minnesota Pollution Control Agency. NPDES permit means the Minnesota Pollution Control Agency's (MPCA's) National Pollutant Discharge Elimination System (NPDES) Phase II Municipal Separate Storm Sewer System (MS4) permit. Preserve wetlands means exceptional and highest-functioning wetlands, or those sensitive wetlands receiving conveyed stormwater runoff that have yet retained a medium level of vegetative diversity/integrity. These wetlands are those that should be preserved in (or improved to) their most pristine or highest functional capacity with wide, natural buffers, in perpetuity. (20) 2 L-___ Sediment control means best management practices employed to prevent sediment from leaving site including, but not limited to: silt fence, sediment traps, earth dikes, check dams, subsurface drains, pipe slope drains, storm drain inlet protection and temporary or permanent sediment basins as defined in the MPCA General Construction Permit. (7, 19) Storm Water Pollution Prevention Plan (SWPPP) means a plan for stormwater discharge that includes erosion prevention measures and sediment controls that, when implemented, will decrease soil erosion on a parcel of land and decrease off-site nonpoint pollution, as defined in the MPCA General Construction Permit. Surface Water Management Plan (SWMP) means the most recently adopted version of the Chanhassen Surface Water Management Plan. WCA agent means the city staff member responsible for the administration of the Minnesota Wetland Conservation Act. (20) Wetland Conservation-'A.ct (or WCA) means the Wetland Conservation Act of 1991, as amended (M.S. ~ 103F.612 et seq.), and the accompanying rules of the Minnesota Board of Water and Soil Resources (Minnesota Rules Chapter 8420, as amended). (20) Wetland alteration means draining, grading, excavating, filling, removing healthy native vegetation, or otherwise altering or destroying a wetland. (20) Wetland management activity means planting seed or live plant material, burning, chemically treating, removing topsoil or utilizing other means for the sole purpose of managing native plant communities and/or eradicating invasive, nonnative vegetation. (20) Section 4. This ordinance shall be effective immediately upon its passage and publication. PASSED AND ADOPTED this _ day of _, 200_, by the City Council of the City of Chanhassen, Minnesota Todd Gerhardt, City Manager Thomas A. Furlong, Mayor (Published in the Chanhassen Villager on ) 3 CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA ORDINANCE NO. AN ORDINANCE AMENDING CHAPTER 7 CHANHASSEN CITY CODE, BUILDINGS AND BUILDING REGULATIONS THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS: Section 1. The City Code, City of Chanhassen, Minnesota, is hereby amended by adding a section to be numbered Section 7-19 (20) which shall read as follows: Location and type of erosion and sediment control measures to be installed by permit holder. Section. Section 7-22 of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: (a) A satisfactory erosion and sediment control plan and grading plan consistent with the city's Surface Water Management Plan must be approved by the city engineer or designee before a building permit is issued for construction, if the construction will result in disturbing the soil. The erosion and sediment control plan shall be illustrated and summarized, by the applicant at the time of application. Guidance documents shall be listed in the Surface Water Management Plan and on the city website. To guarantee compliance with the plan a $500.00 cash escrow or letter of credit, satisfactory to the city, shall be furnished to the city before a building permit is issued. The escrow amount may be greater than $500.00 if, after review of the site, the city deems it necessary to require a greater amount to guarantee compliance. The maximum escrow allowable per parcel is $5,000.00 per acre. The city may use the escrow or draw upon the letter of credit to reimburse the city for any labor or material costs it incurs in securing compliance with the plan or in implementing the plan. If the city draws on the escrowed funds, no additional building permits shall be issued until the pre-draw escrow balance has been restored. The city shall endeavor to give notice to the owner or developer before proceeding, but such notice shall not be required in an emergency as determined by the city. (b) The grading and erosion control plan must be consistent with the approved grading plan for the plat in which the property is located, if any. (c) Every effort shall be made to minimize disturbance of existing ground cover. No grading or filling shall be permitted within 40 feet of the ordinary high water mark of a water body unless specifically approved by the city. 1 (d) Every effort shall be made during the building permit application process to determine the full extent of erosion control required. HoWever, the city engineer may require additional controls to correct specific site related problems as normal inspections are performed. (e) All erosion control noted on the approved plan shall be installed prior to the initiation of any site grading. Noncompliance with the grading and erosion control plan shall constitute grounds for an order from the city engineer to halt all construction. (f) All construction activity that results in disturbance of the ground shall comply with the city's Surface Water Management Plan. (g) If the erosion and sediment control measures have not been installed or maintained properly, the city reserves the right to stop further work. (h) Temporary or permanent erosion control shall be installed on all exposed soils not actively being graded consistent with conditions of NPDES construction permit or as detailed in the 2005 MN DOT construction specification handbook, specification 2575. Section 3. The City Code, City of Chanhassen, Minnesota, is hereby amended by adding a section to be numbered 7-34 (4), which shall read as follows: Obtain all applicable permits as required and work within the requirements of the permits. Section 4. Section 7-35 (b) (12) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: Plans for drainage, erosion and sediment control and dust control. Section 5. This ordinance shall be effective immediately upon its passage and publication. PASSED AND ADOPTED this _ day of _,200_, by the City Council of the City of Chanhassen, Minnesota Todd Gerhardt, City Manager Thomas A. Furlong, Mayor (Published in the Chanhassen Villager on. ) 2 CITY OF CHANHASSEN CARVER AND HltNN:E:PIN COUNTIES, MINNESOTA ORDINANCE NO. AN ORDINANCE AlVIENDING CHAPTER 13 CHANHASSEN CITY CODE, NUISANCES THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS: Section 1. Section 13-2 (a) (15) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: The pollution of any public well, stream, river, lake, wetland, storm sewer or body of water by chemical, organic, industrial, agricultural, commercial, residential, sewage, yard, construction and animal wastes. Section 2. This ordinance shall be effective immediately upon its passage and publication. PASSED AND ADOPTED this _ day of _, 200_, by the City Council of the City of Chanhassen, Minnesota Todd Gerhardt, City Manager Thomas A. Furlong, Mayor (Published in the Chanhassen Villager on ) CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA ORDINANCE NO. AN ORDINANCE AMENDING CHAPTER 18 CHANHASSEN CITY CODE, SUBDIVISIONS THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS: Section 1. Section 18-62 (a) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: The development shall conform to the topography and soils to create the least potential for soil erosIOn. Section 2. Section 18-62 (d) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: Subdivision development shall conform to the city's Surface Water Management Plan. Section 3. Section 18-63 (a) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: All subdivisions shall comply with the city's surface water management plan dated August 2006, which is incorporated herein by this reference. Section 4. Section 18-63 (b) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: In accordance with the city's surface water management plan as a condition of subdivision approval, subdividers shall pay a water quality and water quantity connection charge. The charge shall be based upon the gross area of the subdivision less the area to be dedicated to the city for ponding, parks and wetland, and right-of-way for state highways, county roads, and local arterial roadways. The connection charges per acre for water quality and water quantity are outlined in subpart (c) 3 of Section 4-30. The subdivision will be given a credit for on-site stormwater quality improvements that are designed to treat runoff from the subdivision to NURP standards. The credit will be calculated using the following formula: The per acre water quality connection charge will be multiplied by the on-site drainage area for water quality treatment facilities. This value will then be multiplied by 50 percent. The subdivision will also be given a credit for on-site storm water quality improvements that are oversized to treat runoff from property outside the subdivision to NURP 1 standards. The credit will be calculated using the following formula: The per acre water quality connection charge will be multiplied by the off-site drainage area for water quality treatment facilities. This value will then be multiplied by 50 percent. Credit will not be granted if the stormwater from contributing off-site areas is already treated to NURP standards. The water quality connection charges that correspond to the land uses that contribute to the stormwater ponds will be used to calculate credits. The charge for lots oversized due to individual on-site sewage disposal and water systems will be reduced to the charge that would be imposed on a one-half-acre lot. An additional charge will then be imposed if the lot is further subdivided less a credit for the charge previously paid. The charge shall be paid in cash before the subdivision is approved by the city unless the city and subdivider agree that the charge may be assessed against the property. Property being subdivided shall be exempt from the water quality and water quantity connection charges imposed by this section if the charges were paid or assessed in conjunction with a previous subdivision of the property and if the property is not being zoned to a classification with a higher charge. Section 5. This ordinance shall be effective immediately upon its passage and publication. PASSED AND ADOPTED this _ day of _,200_, by the City Council of the City of Chanhassen, Minnesota Todd Gerhardt, City Manager Thomas A. Furlong, Mayor (Published in the Chanhassen Villager on ) 2 CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA ORDINANCE NO. AN ORDINANCE AMENDING CHAPTER 19 CHANHASSEN CITY CODE, WATER, SEWERS AND SEW AGE DISPOSAL THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS: Section 1. The City Code, City of Chanhassen, Minnesota, is hereby amended by adding sections to be numbered 19-101 through 19-102, which shall read as follows: Sec. 19-101. Unlawful discharge. As provided in this Article and the city's NPDES permit, it shall be unlawful to discharge to any storm sewer any pollutant waters. Sec. 19-102. Regulations for use of storm sewer. (a) No person shall throw, deposit, place, leave, maintain or keep or permit to be thrown, placed, left, maintained or kept, any refuse, rubbish, garbage or any other discarded or abandoned objects, articles, or accumulations, in or upon any street, alley, sidewalk, storm drain, inlet, catch basin, drainage structure, business place, or upon any public or private plot of land so that the same might be or become a pollutant, except in containers, recycling bags, or other lawfully established waste disposal facility. (b) No person shall intentionally dispose of grass, leaves, dirt, or other landscape debris into a lake, wetland, storm water pond, wetland buffer strip, street, road, alley, catch basin, culvert, curb, gutter, inlet, ditch, natural watercourse, ravine, flood control channel, canal, storm drain or any fabricated natural conveyance. (c) No person shall leave, deposit, discharge, dump, or otherwise expose any chemical or septic waste in an area where discharge to streets or the storm sewer system may occur. (d) No person shall use any storm sewer connection to intentionally convey non-storm water to the storm water system. (e) Objects, such as motor vehicle parts, containing grease, oil or other hazardous substances, and unsealed receptacles containing hazardous materials, shall not be stored outdoors. (f) Fuel and chemical residue or other types of potentially harmful material, such as animal waste, garbage or batteries, which is located outdoors shall be removed as soon as possible and disposed of properly. Household hazardous waste shall not be placed in a trash container. 1 (g) No person shall maliciously, willfully of negligently break, damage, destroy, uncover, deface or tamper with any structure, appurtenance or equipment which is a part of the city storm sewer system. (h) The following activities shall be determined exempt from the provisions listed in this article: (1) City staff or city contractors during the course of conducting maintenance activities; and (2) Metropolitan Mosquito Control District during the course of conducting mosquito control activities. Section 2. Sections 19-140 through 19-148 of the City Code, City of Chanhassen, Minnesota, are hereby repealed. Section 3. The City Code, City of Chanhassen, Minnesota, is hereby amended by adding sections to be numbered 19-140 through 19-146, which shall read as follows: ARTICLE VII. SURFACE WATER MANAGEMENT. Sec. 19-140. Purpose. The purpose of this ordinance is to implement standards to achieve the goals and policies set fOlth in the city's Surface Water Management Plan in order to preserve, protect and improve the city's surface water resources. Sec. 19-141. Development standards. These development standards shall be reflected in plans prepared by developers and/or project proposers in the design and layout of site plans, subdivisions and water management features. Sec. 19-142. Plans required. All plans shall be reviewed and stamped "Approved by the City Engineer" and all applicable permits must be obtained prior to commencing construction. For all newly constructed storm water facilities (ponds, retention areas, infiltration basins, storm sewer, etc.) or existing facilities that are modified, as-built plans shall be prepared by the developer. As-built plans shall be signed and certified by a licensed professional engineer in the State of Minnesota and record drawings shall be provided to the city. Standard details for many typical storm structures (e.g., storm sewer, outlet structures, catch basins, sump manholes, etc.) are available on the city's website. Sec. 19-143. General elements. (a) Hydrologic Analysis 1. Storm distributions and storm volumes for hydrologic analysis shall be based upon Hershfield, D.M., 1961, Rainfall Frequency Atlas of the United States for Durations of 30 2 Minutes to 24 Hours and Return Periods from 1 to 100 Years, Technical Publication No. 40 (TP-40). 2. Design of major facilities (e.g., ponds, detention areas, retention areas) shall be based on the U.S.D.A. NRCS methods, 100-year return period, 24-hour duration, type II distribution with average soil moisture conditions (AMC-2). The analysis of flood levels, storage volumes and discharge rates for detention basins shall utilize the design storm/freeboard evaluation storm concept. 3. Minor drainage systems (storm sewer) shall be analyzed and designed to protect for the 10 year frequency rainfall, and shall be evaluated for the 100-year frequency rainfall. Full pipe flow analysis shall be used unless special conditions can be demonstrated to consider pressure flow. 4. The Rational Method is the accepted design method for the design of minor systems (storm sewer). The preferred method of design would be a method utilizing a hydro graph approach with factors for land use and soil moisture conditions. NRCS methodology is not acceptable for minor system design unless approved by the City Engineer. 5. Landlocked storm water basins shall be designed to hold back-to-back 100-year storms. For landlocked areas, available freeboard and infiltration capacity of in-place soils should be analyzed (if analyzed for unfrozen soil conditions). (b) Peak Discharge Rates 1. Peak storm water discharge rates and storage volumes from any drainage area, watershed, subwatershed, detention basin, wetland or conveyor shall be consistent with the values shown in this plan for the 100-year storm event. 2. No increase in peak discharge rate may result from the proposed project for the 1 or 2-year stonTI, the lO-year storm and the 100-year storm event. Variances may be allowed if computations can be provided which demonstrate no adverse downstream effects will result from the proposed system. Cumulative storm depths for the required events are: a) 2-Year = 2.8 inches b) 10-Year = 4.2 inches c) 100- Year = 6.0 inches (c) General Facility Planning 1. Developments shall maximize preservation and use of natural detention areas and regional detention areas shall be used to the greatest practical extent. Multiple purpose detention areas are encouraged to maximize maintenance efficiency within proposed developments while providing the proper flood control and water quality features. 2. The construction of detention basins will involve the direct participation of individual developers. Where regional basins serve multiple properties and may lie outside of the ownership of the specific development, the City and WDs will take an active role on 3 implementing policy. Because the basis for the hydrology is based on the developer's grading plan, the developer is required to obtain and submit the certification of a licensed engineer that the detention areas are constructed to the specifications of the approved design. Sec. 19-144. Major facility design elements. (a) Facility Design Cliteria (1) For design or modification of storm water facilities, the following criteria shall be followed: a. All hydrologic data and computations shall be based on NRCS (formerly SCS) methodology. Computer modeling may be completed using HydroCAD, TR20/TR55, SWMM or comparable City-approved modeling software. b. Hydraulic computations shall be completed using the rational method for storm sewer design, or in commonly used software packages including FHW A HY-8, Geopack, Eagle Point or SWMM compatible software. c. Water quality modeling shall be completed using Pondnet, P8 Urban Catchment Model, SLAMM or comparable software. d. Outlet structure designs shall provide rate controls that limit post-project rates to not exceed existing rates for 1 or 2-year, 1O-year, 100-year events and 100-year/1O-day snowmelt. e. An emergency overflow spillway shall be identified and designed to convey storm flows from events greater than the 100-year event. Extreme events (on the order of a 10.0 inch event) shall be analyzed to ensure the emergency overflow spillway will function as designed. An emergency overflow shall be set an elevation at least 1.5 feet below the lowest adjacent low building elevation. f. Maximum 3:1 (H:V) side slopes (see diagram that follows). g. 10:1 (H:V) safety bench from normal water level (see diagram that follows). h. For basins intended to have permanent water levels, a minimum of four feet of standing water (dead storage depth) and a maximum of ten feet shall be provided. i. Proper allowance shall be made for future access and maintenance. Easements shall be greater than or equal to 20 feet wide. j. Separation between the inlet(s) and outlet shall be maximized to prevent short- circuiting. 4 (2) The facility design shall provide adequate live storage to provide protection from the design storm, consistent with lowest building elevation standards. Lowest building floor elevation is defined as the lowest slab elevation for a home or building, including basements and crawl spaces. The lowest building floor elevation for structures adjacent to wetlands and water bodies shall be an elevation three feet above the 100-year high water level. (3) Newly constructed or modified detention basins shall provide storage volume below the outlet (dead storage) to allow for water quality treatment in accordance with the following, whichever is most restrictive: a. Water quality features meeting the MPCA NPDES construction permit for Permanent Storm Water Management Systems; b. Water quality treatment consistent with NURP criteria (90% removal of TSS and 60% removal of TP for a standard NURP particle size distribution); and/or c. For proposed projects in a watershed that directly discharges to a 'Preserve' water feature (Table 20 of SWMP), NURP plus enhanced treatment is required as listed below: 1. Storm water ponds are required to include a sediment forebay at the inlet. The volume of the sediment forebay should be 5 - 15% of the permanent pool surface area. The sediment forebay shall be a minimum of 3 feet plus the depth for sediment storage. 2. Projects in watersheds that discharge directly to Assumption Creek must incorporate BMPs as outlined in Appendix A C.l, Co2, C.3 and C.5 of the MPCA NPDES Construction General Permit, and as listed below: 1. During construction. a. All exposed soil areas with a slope of 3:1 or steeper, that have a continuous positive slope to a special water must have temporary erosion protection or permanent cover within 3 days after the area is no longer actively being worked. All other slopes that have a continuous positive slope to a special water must have temporary erosion protection or permanent cover within 7 days after the area is no longer actively being worked. 5 b. Temporary sediment basin requirements described in Part IILB.1-5 of the NPDES Construction Genetal Permit must be used for common drainage locations that serve an area with five (5) or more acres disturbed at one time. 2. Post construction. The water quality volume that must be treated by the project's pelmanent storm water management system described in Part IILC of the NPDES Construction General Permit shall be one (1) inch of runoff from the new impervious surfaces created by the project. 3. Buffer zone. An undisturbed buffer zone of not less than 100 linear feet from the special water (not including tributaries) shall be maintained at all times. Exceptions from this requirement for areas, such as water crossings or limited water access, are allowed if the Pelmittee fully documents in the SWPPP the circumstances and reasons that the buffer encroachment is necessary. All potential water quality, scenic and other environmental impacts of these exceptions must be minimized and documented in the SWPPP for the project. 4. Temperature Controls. The permanent storm water management system must be designed such that the discharge from the project will minimize any increase in the temperature of trout stream receiving waters resulting from the 1, and 2-year 24-hour precipitation events. This includes all tributaries of designated trout streams within the section that the trout stream is located. Projects that discharge to trout streams must minimize the impact using one or more of the following measures, in order of preference: a. Minimize new impervious surfaces. b. Minimize the discharge from connected impervious sUlfaces by discharging to vegetated areas, or grass swales, and through the use of other non-structural controls. c. Infiltration or evapotranspiration of runoff in excess of pre-project conditions (up to the 2-year 24-hour precipitation event). d. If ponding is used, the design must include an appropriate combination of measures such as shading, filtered bottom withdrawal, vegetated swale discharges or constructed wetland treatment cells that will limit temperature increases. The pond should be designed to draw down in 24 hours or less. e. Other methods that will minimize any increase in the temperature of the trout stream. d. For proposed projects in a watershed that directly discharges to an 'Improve l' (Table 20 of SWMP) water feature NURP plus enhanced treatment is required as listed below: 1. Storm water ponds are required to include a sediment forebay at the inlet. The volume of the sediment forebay should be 5 - 15% of the permanent pool surface area. The sediment forebay shall be a minimum of 3 feet plus the depth for sediment storage. 2. Projects in watersheds that discharge directly to Riley or Bluff Creeks must analyze the downstream system to ensure there is no increase in runoff rates. One way to determine the downstream effects is to extend the analysis downstream to a point where the proposed development represents less than ten percent of the total watershed draining to that point. 6 (b) Skimmers and Outlets 1. Skimming devices should be designed to remove oils and floatable materials up to a one- year frequency event. The skimmer should be set 12 inches below the normal surface water elevation and should control the discharge velocity to 0.5 fps. 2. Outlets shall be evaluated for the need to dissipate energy so as to reduce velocities to permissible levels as allowed by the soil and vegetation. At a minimum, flared end sections should be provided with riprap consistent with Mn/DOT standards. For areas with high flows or where excessive erosion occurs or is anticipated, energy dissipation per Federal Highway Administration standards shall be followed. 3. Riprap shall be provided below the channel grade and above the outfall or channel bottom to insure that riprap will not be undelmined by scour or rendered ineffective by displacement. Riprap consisting of natural angular stone suitably graded by weight shall be designed for anticipated velocities. Riprap shall be placed over a suitable filter material or filter fabric to insure that soil particles do not move through the riprap and reduce its stability. 4. For outlets through berms or roadway embankments and all culverts under public traveled streets, anti-seepage collars shall be used (see diagram in this section). The collars shall be installed so as to increase the creep distance or seepage line along conduit by 15 percent. The locations for the use of collars include: a. All water and pond structures with a pool depth of two feet and two-day duration. b. 250 acre watershed or more. c. Design head of 10 feet or more. Sec. 19-145. Erosion and sediment control. (a) Erosion and Sediment Control Plans 1. An erosion and sediment control plan shall be created for any land disturbing activity. Erosion and sediment control elements shall be implemented before any grading can begin. A schedule of significant grading work will be required as part of the erosion and sediment control plan. 2. The MPCA's most recent version of the NPDES Construction Storm Water Permit shall be used to develop sediment and erosion control plans. Where the NPDES permit conflicts with City standards, the more stringent standard will apply. 3. Site access roads (entrances to construction sites) shall be graded or otherwise protected with silt fences, diversion channels or dikes and pipes to prevent sediment from exiting the site via the access road. Primary site access roads shall be surfaced with crushed rock or wood chips. The rock entrance shall extend for a minimum distance of 75 feet (150 for wood chips) beginning at existing paved surface; additional length may be required as directed by the City. All construction traffic shall utilize the entire length of the rock entrance. 7 4. Soil tracked from thc site by motor vehicles shall be cleaned from paved roadway surfaces at least daily or as needed throughout the duration of construction. Roadway cleaning shall be the responsibility of the party or patties having a pcrmit with the City. 5. Streambank stabilization and stream bed control structures shall be designed based on the unique site conditions present including soil conditions, flow rate, slope, and flow velocity. 6. Where inadequate natural vegetation exists or where it becomes necessary to remove existing natural vegetation, both temporary vegetative and permanent vcgetative cover shall be addressed in the plans and specifications and be consistent with the provisions of the NPDES Construction permit. (b) Sediment Basins 1. Detention basins may be used as temporary sediment retention during the construction phase. The design should include providing pcnnanent storage volume for construction and restoration phase sediment accumulation or the removal of the sediment to restore the required permanent pool volume in the detention area. 2. Detention areas intended to permanently trap sediments shall provide excess dead storage beyond the required water quality volume, to allow for sediment accumulation. Sediment basins shall be capable of removing coarse suspended sediment from storm water for all runoff events and the greatest practical grain size (#40 typically). Sediment storage volume should be estimated by the universal soil loss equation and 0.5 tons per watershed acre per year. Volume below the outlet can be estimated by using the runoff volume resulting from a 2.5" rainfall. Sec. 19-146. Wetland elements. (a) Water level fluctuations (peak elevation and duration) for wetlands shall be limited to two feet and duration not to exceed 48 hours so as to prevent the destruction of wildlife habitat and wetland vegetation. (b) Sedimentation basins or sediment removal devices shall be provided prior to discharge into wetlands. (c) Variable bottom contours should be considered to provide deeper holes and flat shallow benches. This feature will provide habitat for diversity of plants and wetland inhabitants for wetland mitigation sites and storm water basins. Section 4. The City Code, City of Chanhassen, Minnesota, is hereby amended by adding sections to be numbered 19-200 through 19-208, which shall read as follows: ARTICLE VII. SURFACE WATER MANAGEMENT Sec. 19-200. Surface water management utility established. 8 Surface water management shall be operated as a public utility pursuant to M.S. S 444.075. Sec. 19-201. Definitions. The following words, terms, and phrases, when used in this article, shall have the meaning ascribed to them in this section, except where the context clearly indicates a different meaning: Surface water management budget is the annual budget approved by the city council for surface water management including planning, monitoring, capital expenditures, personnel, and equipment. Surface water management fee means the quarterly charge for each parcel of nonexempt property in the city for the management of surface water. Utility factor means the ratio of runoff volume, in inches, for a particular land use, to the runoff volume, in inches for a one-third-acre residential lot, assuming a two-inch rainfall and soil conservation service (SCS) "type B" soil conditions. Sec. 19-202. Surface water management fees. The surface water management fees for tax parcels shall be calculated in accordance with section 4-50. Sec. 19-203. Credits. The city council may adopt policies for adjustment of the surface water management fees. Information to justify a fee adjustment must be supplied by the property owner. Adjustment of fees shall not be retroactive. Sec. 19-204. Exemptions. The following land uses are exempt from the surface water management fee: (1) Public right-of-way. (2) Lakes. Sec. 19-205. Payment of fee. Surface water management fees shall be involved quarterly. The amount due as shown on the invoice shall be payable on or before the twentieth day of the month in which the invoice is issued. A penalty of ten percent per quarter shall be added to all accounts that are not paid in full by the due date. The penalty shall be computed on the unpaid balance not paid by the due date at the time each quarterly statement is prepared. Any prepayment or overpayment of charges shall be retained by the city and applied against subsequent fees. Sec. 19-206. Appeal of fee. If a property owner or person responsible for paying the surface water management fee believes that a particular fee is incorrect, such person may file a written appeal with the city clerk. 9 Appeals will be heard by the city council. No adjustment will be made to the utility factor for property classifications 1,2, and 3. Sec. 19-207. Certification of delinquent fees. If a surface water management fee is not paid within three months after a billing is issued, the city council may certify the amount due, together with penalties, to the county auditor to be collected with other real estate taxes on the parcel. Sec. 19-208. Surface water management fund. A separate fund shall be maintained for surface water management fees and expenditures. Section 5. This ordinance shall be effective immediately upon its passage and publication. PASSED AND ADOPTED this _ day of _,200_, by the City Council of the City of Chanhassen, Minnesota Todd Gerhardt, City Manager Thomas A. Furlong, Mayor (Published in the Chanhassen Villager on ) 10 CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA ORDINANCE NO. AN ORDINANCE AMENDING CHAPTER 20 CHANHASSEN CITY CODE, ZONING THE CITY COUNCIL OF THE CITY OF CHANHASSEN, MINNESOTA ORDAINS: Section 1. Sections 20-401 through 20-418 of the City Code, City ofChanhassen, Minnesota, are hereby repealed. Section 2. The City Code, City of Chanhassen, Minnesota, is hereby amended by adding sections to be numbered 20-401 through 20-421, which shall read as follows: ARTICLE VI. WETLAND PROTECTION. Sec.20-401. Findings intent; rules adopted by reference. (a). Wetlands help maintain water quality, serve to reduce flooding and erosion, act as sources of food and habitat for a variety of fish and wildlife, and are an integral part of the community's natural landscape. Wet!ands provide the aesthetic benefits of open space and can be used to provide a natural separation of land uses. It is the intent of this ordinance to establish a policy of sound stewardship through coordination of regulations that conserve, protect, enhance, and result in the no net loss of these environmentally sensitive resources. In addition, it is the intent of the city to promote the restoration of degraded wetlands. (b). The intent of this ordinance is to avoid alteration and destruction of wetlands. When this is not feasible, mitigation must be provided to recreate the function and value of the lost or altered wetlands. (c). This ordinance is adopted in part to implement the Wetland Conservation Act of 1991, as amended (M.S. ~ 103F.612 et seq.), and the accompanying rules of the Minnesota Board of Water and Soil Resources (Minnesota Rules Chapter 8420, as amended). (d). This ordinance incorporates by reference the act and the rules. Terms used in this ordinance which are defined in the act or the rules have the meanings given there. Sec. 20-402. Purpose. The purpose of this ordinance is to assure the general health, safety, and welfare of the residents through preservation and conservation of wetlands and sound management of development by: I (1). Conducting an inventory and classification of all wetlands within the city and maintaining a comprehensive set of official city maps depicting the approximate location and extent of wetlands. (2). Establishing wetland regulations that are coordinated with water quantity and water quality goals and policies of the Chanhassen Surface Water Management Plan. (3). Requiring sound management practices that will protect, conserve, maintain, enhance and improve the functions and values of wet!ands within the community. (4). Requiring measures designed to maintain and improve water quality in streams and lakes. (5). Protecting and enhancing the scenic value of wetlands. (6). Restricting, controlling and mitigating the harmful effects of development on wetlands. (7). Allowing only development that is planned to be compatible with wetland protection and enhancement. (8). Providing standards for the alteration of wetlands when alteration is allowed. (9). Educating and informing the public about the numerous benefits and features of wetlands and the impacts of urbanization. (10). Obtaining protective easements over or acquiring fee tit!e to wetlands as appropriate. Sec. 20-403. No net loss. (a). To achieve no net loss of wetland, except as provided under sections 20-417 and 20-418 of this ordinance or authorized by a wetland alteration permit issued by the city, a person may not drain, grade, excavate, fill, bum, remove healthy native vegetation, or otherwise alter or destroy a wetland of any size or type. Any alteration to a wetland permitted by a wetland alteration permit must be fully mitigated so that there is no net loss of wetlands. (b). Wetlands shall be subject to the requirements established herein, as well as restrictions and requirements established by other applicable city ordinances and regulations. The wet!and protection regulations shall not be construed to allow anything otherwise prohibited in the zoning district where the wetland area is located. (c). All activities within the City shall comply with the Wetland Conservation Act of 1991, as amended (M.S. ~ 103F.612 et seq.), and the accompanying rules of the Minnesota Board of Water and Soil Resources (Minnesota Rules Chapter 8420, as amended). Where the requirements of City Code differ from those requirements, the more restrictive shall apply. Sec. 20-404. Official wetland map. (a). The City shall maintain the official City Wetland Inventory, which is hereby adopted by reference. An electronic copy of this map shall be maintained on the City's Geographic 2 Information System (GIS) database, with both hard and electronic copies being made available for public review upon request. (b). The City Wetland Inventory shall identify each basin as one of four management categories: Preserve, Manage 1, Manage 2, and Manage 3. These classifications will be determined using Figure 1.1 "Wetland Management Classification Process Flowchart for Basic Wetland Protection" from Minnesota Routine Assessment Method for Evaluating Wetland Functions (MnRAM Version 3.0), or future versions. ( c). The presence or absence of a wetland on the City Wetland Inventory does not represent a definitive determination as to whether a jurisdictional wetland that would be covered by this ordinance is present. Wetlands identified during a site-specific delineation, but not identified by the City Wet!and Inventory, are still subject to the provisions of this ordinance. (d). The City Wet!and Inventory does not depict delineated wetland boundaries and shall not be used as such. ( e). The City Wetland Inventory shall be amended to include any wetlands discovered during the site review process. Sec. 20-405. Wetland delineation. (a). It is the responsibility ofthe project applicant to determine whether a wet!and exists on a subject property. It is the responsibility of the applicant to complete a wetland delineation and submit sufficient documentation of the wetland boundary to the city in a Wetland Delineation Report. Wet!and delineations shall be completed by, or under the direct supervision of, a Certified Wetland Delineator. Three (3) hard copies of the Wet!and Delineation Report must be submitted to the city's WCA agent. Additionally, an electronic copy of the delineated wetland boundaries must be submitted in a format compatible with the city's GIS database. Wetland delineations shall be valid for three years. Wetland delineations completed more than three (3) years prior may be confirmed and/or updated by a qualified wetland professional through a site visit and submittal of a summary of the findings, a copy of the old delineation and a map depicting both the original and revised wet!and boundaries, where applicable. (b). Wetland delineations do not need to be completed for properties adjacent to a proposed development that is under separate ownership. However, sufficient information must be presented to demonstrate that any proposed activities shall not directly or indirectly impact adjacent basins. The applicant shall review readily available information including, but not limited to, the City Wetland Inventory, National Wetland Inventory maps, topographic maps, soil survey maps, and recent and historic aerial photographs in preparing this assessment. Sec. 20-406. Wetland classification. (a). All wetlands delineated under section 20-405 of this ordinance that have not been previously classified shall be classified using the results from the Minnesota Routine Assessment Method for Evaluating Wetland Functions (MnRAM Version 3.0), or future versions. 3 (b). A MnRAM shall be completed by the property owner or applicant for each previously unclassified wetland. An electronic version of the MnRAM evaluation must be submitted to and approved by the city to establish the classification of each wet!and prior to any alteration or impact to the wetland. (c). MnRAM 3.0 assessments have been completed by the City as a component ofthe City Wetland Inventory. Applicants; however, may appeal the determination, and submit a request to change the classification. To do so, the applicant must submit an electronic copy of the MnRAM for each affected basin to the WCA agent. The forms must be filled out by a qualified wetland scientist. The WCA agent will consult with the technical evaluation panel to determine if a change in the classification is warranted. In all cases, the burden to demonstrate the need for a change in classification lies with the applicant. Sec.20-407. Permit required. (a). No person shall drain, excavate in the permanent or semipermanent flooded areas of open water wetlands, or fill a wetland, wholly or partially, or otherwise impact wetlands without first having a wetland replacement plan or other determination approved by the city. Draining, grading, excavating, filling, removing healthy native vegetation, or otherwise altering or destroying a wet!and of any size or type not subject to an exemption under section 20-417 of this chapter requires a wet!and alteration permit Activity in a wetland requiring a wetland alteration permit includes, but is not limited to: (1). Construction of new streets and utilities. (2). Creation of ponds or dams and alterations of the natural drainageways of water courses. This shall only be allowed as part of a mitigation project, or to restore or improve the function and value of the wetland. (3). Installation of boardwalks and docks. Docks shall meet the additional requirements in Chapter 6, Article II of the Chanhassen City Code. (4). Discharge of untreated stormwater runoff into wetlands. (5). Changes in wet!and hydrology that result in an increase in the ordinary high water level of a wetland by more than 12 inches. (b). The city must be notified at least five business days prior to the use of any form of treatment of wetlands to control nuisance vegetation including chemically treating, burning, mowing or biologically treating wetlands. (1). At the time of notification, a person or company will be required to supply the following information: a. Location of wetland; b. Area of wetland to be treated; c. N arne, address and telephone number of the party responsible for treatment; d. Name, address and telephone number of person or persons performing the treatment; 4 e. Date of treatment; f. A list of the type of treatments to be used at such time; g. A statement indicating an understanding of the treatment being applied and its effect on humans, plants and wildlife; and h. A signed consent from all property owners owning property containing or abutting wetland to be treated. ( c). The following activities shall be determined exempt from the provisions listed in subpart (b) above: (1) Federal, state or local government staff or contractors during the course of conducting maintenance activities; and (2) Metropolitan Mosquito Control District during the course of conducting mosquito control activities. Sec. 20~408. Exemptions from earth work permit requirements. Earth work completed in accordance with an approved wetland alteration permit is exempt from the requirement to obtain a separate earth work permit. Sec. 20-409. Permit application requirements and decisions. (a). A wetland alteration permit shall not be issued without having been first reviewed by the planning commission and approved by the city council following the review and hearing procedures set forth for conditional use permits and the additional requirement of Minnesota Rules 8420.0230. The applicant shall have the burden of proving that the proposed use or activity complies with the purposes, intent and other provisions of this ordinance. The council may establish reasonable conditions which are specifically set forth in the permit to ensure compliance with requirements contained in this ordinance. Such conditions may, among other matters, limit the size, kind or character of the proposed work; require the construction of other structures; require replacement of vegetation and wet!and functions and values; establish required monitoring procedures and maintenance activities; stage the work over time; require the alteration of the site design to ensure buffering; and/or require the provision of a performance security. (b). Any projects seeking a wet!and alteration permit subject to this ordinance will be required to submit the following: (1). A wetland alteration permit application (2). A site/grading plan of the entire property (3). Existing and proposed drainage areas to wetlands (4). A wetland delineation report in accordance with section 20-405 (5). Wetland classification information in accordance with section 20-406 for each wetland on property (6). Buffer strip plan meeting the criteria of section 20-411 (c) and (d) (7). Submittals required by the Wetland Conservation Act (8). Topographic data (9). Other information as required by the city 5 (c). Decisions made under this ordinance that fall under the authority ofthe Minnesota Wetland Conservation Act may be appealed to the Minnesota Board of Water and Soil Resources under Minnesota Rules 8420.0250, after administration appeal rights under the official controls have been exhausted. Staff costs to the city associated with appeals shall be borne by the applicant. (d). The city council shall appoint a person to serve on a technical evaluation panel. The person must be a technical professional with expertise in water resources management. Decisions under this ordinance must not be made until after receiving the determination of the technical evaluation panel regarding wetland public values, location, size, and/or type if the city council, the landowner, or a member of the technical evaluation panel asks for such determinations. This requirement does not apply to wetlands for which such data is included in an approved comprehensive wetland management plan per Minnesota Rules 8420.0240. The city council may seek and consider recommendations, if any, made by the technical evaluation panel in making replacement plan decisions. Unless otherwise designated, the city's representative on the technical evaluation panel shall be the WCA agent. ( e). The applicant for a wetland alteration permit is responsible for obtaining all other necessary permits including but not limited to those required by watershed districts, Minnesota Department of Natural Resources, United States Army Corps of Engineers and Minnesota Pollution Control Agency prior to commencement of the permitted work. Sec.20-410. General standards. (a). The following standards apply to all lands within and abutting a wetland: (1). Septic and soil absorption system must be a setback minimum of75 feet from the ordinary high water mark of the wet!and. (2). The lowest ground floor elevation of a principal structure is three feet above the 100- year flood elevation of the wetland. (3). Access across a wet!and shall be by means of a boardwalk or elevated structure and only upon approval of a wetland alteration permit. Wet!and crossings must also be in conformance with all other state regulations. (4). Docks and boardwalks shall be elevated a minimum of six inches above the ordinary high water mark. Docks and boardwalks shall only be permitted to cross wetlands in instances where a wetland is riparian to a lake. (5). The erosion and sediment control goals and policies within the city's Surface Water Management Plan shall be met. (6). Stormwater runoff shall not be discharged into wetlands without water quality pretreatment as prescribed by Chanhassen City Code. (b). When a wetland alteration permit is issued allowing wetland alteration, the following standards shall be followed: (1). The alteration will not have a net adverse effect on the ecological and hydrological characteristics of remaining wetland. 6 (2). It shall be located as to minimize the impact on vegetation. (3). It shall not adversely change water flow. (4). The size of the altered area shall be limited to the minimum required for the proposed action. (5). The disposal of any excess material is prohibited within remaining wetland areas. (6). The disposal of any excess material shall include proper erosion control and nutrient retention measures. (7). Alterations to any wet!and area are prohibited during waterfowl breeding season or fish spawning season, unless it is determined by the city that the wetland is not used for waterfowl breeding or fish spawning. (8). Alterations to wetland areas shall be mitigated in accordance with the requirements of this ordinance ifthe activity results in a loss of wetland area and/or function and value ofthe wetland. (9). Dedicated buffers in accordance with section 20-411. Sec. 20-411. Placement of structures. (a). For lots created on or after (date of codification), a buffer strip shall be maintained abutting all wetlands. All existing vegetation adjacent to a wetland shall be left undisturbed and applied toward the buffer strip unless otherwise approved by the WCA agent or city council. Buffer strip vegetation shall be established and maintained in accordance with the following requirements. If the buffer strip is disturbed, native plant species shall be selected from wetland and upland plants to provide diverse habitat for various species of wildlife. Buffer strips shall be identified by permanent monumentation acceptable to the city. A minimum of one wetland buffer monument is required per lot abutting the wetland edge. The maximum spacing between monuments is 300 feet. (b). The following table provides the minimum standards required for each wet!and classification. Structure Setback Permanent Buffer Percent of Buffer Wetland from Buffer Edge Strip Minimum Strip in Native Classification (feet) Width (feet) Vee:etation Preserve 50 50 100% Manage 1 40 30 100% Manage 2 40 25 Over 50% Manage 3 40 20 Over 50% 7 I I I 61na:.. 31- MANAGE 3 WETLAND ILLUSTRATION BUFFER I I HOllE FRONr YARD s 30--1 I I I I 0' I , FRC)II1mIACK BUFFER 40' wlvw I I I I I I I (c). For lots of record prior to (date of codification), the minimum buffer strip and setback requirements shall comply with subparagraph (b) above. Ifbuffer strips and setbacks were approved as part of the subdivision, those standards shall prevail, except that in no case shall structures be set back less than 40 feet from the wetland edge. (d). The Planning Commission or City Council may approve variances from applicable buffer strips and setback requirements if suitable hardship can be demonstrated. In these instances, additional performance standards may be enforced to compensate for the reduced buffer strip widths or setbacks. (e). In addition to the requirements above, wetland buffer strips for wet!and mitigation areas and those counted as Public Value Credit (PVC) shall also conform to the minimum standards as set forth by the Wetland Conservation Act. (t). No structures are to be placed within the wetland setback. (g). For any subdivision, the locations of buffer strips and wetland setbacks shall be surveyed and recorded on the Property Title and Certificate of Survey. A Certificate of Occupancy shall not be issued unless this task is completed and approved by City staff. (h). Retaining walls may be located within wetland setbacks, but neither the walls nor the land alteration that takes place as part of wall construction shall encroach into the required buffer strips. 8 Sec. 20-412. Buffer strips required. (a). Before release of final plat, the applicant must submit to the WCA agent a drainage and utility easement for protection of the wet!and and approved buffer strip. The easement must describe the boundaries of the wet!and and the wetland buffer strips (b). Building structures, paving, mowing, introducing non-native vegetation, cutting, filling, dumping, disposing of yard waste, fertilizing, or tampering with the monuments within buffer strips is prohibited. (c). Additional wetland impacts shall not be allowed for the creation of buffer strips. (d). The use of meandering buffer strips to maintain a natural appearance is encouraged (e). Where roadways are constructed next to a wetland, a buffer strip shall be maintained. (t). Where acceptable natural vegetation exists in a wetland and adjacent buffer strip, the retention of such vegetation in an undisturbed state shall be required unless the applicant receives approval to replace such vegetation. A wetland and/or buffer strip has acceptable vegetation if it is dominated by native tree, shrub, or grass species, and has not been used for agricultural production in the last five years. (g). The WCA agent may deny the use of existing vegetation for the use of buffer strips if: 1. It is dominated by any species on the state noxious weed list as defined by Minnesota Statutes, Section 18.76-18.88. These species include species such as leafy spurge, spotted knapweed, purple loosestrife, and common and glossy buckthorn; 2. It is present on unstable slopes, has significant bare soil, displays a history of erosion problems, is prone to gully formation, or does not function for sediment and nutrient removal; 3. Any areas were used for agricultural production in the last five years; or 4. The buffer strip is disturbed or altered. (h). If an area is deemed to be unacceptable in its current state, wet!and buffer landscaping plan must be submitted to the WCA agent. This plan shall include at a minimum: 1. A plan sheet showing the proposed new buffer strip locations and any buffer strips acceptable as existing. Existing buffer strips shall be identified and marked to prevent accidental disturbances. 2. A specification as to what seed mixture will be used, or what trees and/or shrubs will be planted and their locations. 3. A verification that all seed stock and tree species are native to Minnesota and are of local ecotypes. 4. A detailed specification that identifies the project schedule, materials, installation or seeding instructions, and costs. 5. A maintenance schedule that describes the activities that will occur for at least the first two (2) years. This should include a schedule of mowing and spot spraying for weeds if 9 an area is seeded. Plans that call for periodic burning shall have additional details and must have special permission prior to installation. 6. A detail of all Best Management Practices (BMPs) and erosion control plans. 7. A plan identifying the locations of buffer strip markers. 8. An electronic copy of plans in a format compatible with the City GIS database. (i). The city may, at their discretion, require a cash escrow or letter of credit up to 110% of the cost to reestablish the buffer strip should it not be successful, not be maintained, or otherwise require city intervention to maintain the ordinance requirements. Sec. 20-413. Wetland alteration. (a). An applicant for a wetland alteration permit must demonstrate that the activity impacting a wetland has complied or, through imposition of conditions of approval, will comply with all of the requirements of the Wetland Conservation Act. (b). A wetland alteration permit shall not be issued unless the proposed development complies with this article. (c). When a wetland alteration permit is issued allowing wetland alteration, the alteration must be consistent with the city's Surface Water Management Plan and the Wetland Conservation Act. The alteration shall not alter the hydrological patterns in the remainder of the wetland, if a portion of the wetland remains, unless exempted under section 20-417. Sec. 20-414. Wetland management activities. Prior to commencement of a wetland management activity, an administrative wetland permit must be obtained for the activity in accordance with section 20-415. Sec. 20-415. Administrative wetland permit. (a). Applications for administrative wetland permits shall be made on a form supplied by the city. A fee shall be paid as set forth in Chanhassen City Code. The WCA agent shall review applications to ensure proposed activities are in compliance with the Wetland Conservation Act and the requirements of this ordinance and are consistent with approved and/or accepted wetland management practices. (b). Activities for which administrative wetland permits are approved shall not contribute to nuisances as defined in the Chanhassen City Code. Sec. 20-416. Mitigation. (a). Mitigation intent. Where a wetland alteration permit is approved and mitigation is required pursuant to City Code and the Wetland Conservation Act, mitigation must result in an improvement to the wetland function and value. Mitigation plans must address water quality, improvement, and maintenance of preexisting hydrological balance and wildlife habitat. The wetland function and value will include improvement of water quality, maintaining hydrological 10 balance, and provision of wildlife habitat. Mitigation will be performed at ratios required by the Minnesota Wetland Conservation Act to achieve replacement of the wetland function and value. (b). Mitigation standards. The functions and values of mitigation wetlands shall be achieved through wetland restoration, creation and/or enhancement. The mitigation standards found in Minnesota Rules 8420.0550 shall be followed. (1). Mitigation shall be subject to wetland setback and buffer strip requirements as set forth in this ordinance. (2). Mitigation shall at a minimum replace preexisting wetland function and values through the ratios set forth in Minnesota Rules 8420.0541. (3). Mitigation, through the buffer strip, shall provide landscaping for nesting and food for wildlife habitat. The buffer strip shall provide for wildlife cover and utilize a diversity of native flora (i.e., trees, shrubs, grasses, herbaceous plants) to encourage wildlife diversity and provide visual variety. (4). Wetland mitigation shall be undertaken on-site. Ifthis is not feasible, then mitigation may occur locally within the subwatershed. If this is not possible, then mitigation may occur outside the subwatershed, elsewhere in the city. If mitigation cannot be accomplished on site, or if the city deems it necessary to perform mitigation off-site, then the applicant shall be responsible for providing off-site mitigation within the major sub watershed, as designated by the Minnesota Wetland Conservation Act, or purchasing wetland credits from the state wetland banle (d). Construction management and long term wetland maintenance. (1). The wetland alteration permit holder shall follow best management practices to minimize direct impacts due to erosion and construction practices and to safeguard wildlife habitat. (2). The wetland alteration permit holder shall submit an annual report to the city for replacement wetlands in Chanhassen. The purpose of the annual report is to describe actual wetland management, restoration or creation activities completed during the past year as well as activities planned for the upcoming year. The annual report shall include all the information required of annual monitoring reports by Minnesota Rules 8420.0620 subpart 2. The wetland alteration permit holder shall submit annual monitoring reports as required by Minnesota Rules 8420.0610. Submission shall continue for at least five years or until the replacement wetland is deemed by the Technical Evaluation Panel (TEP) to be fully functional. Where feasible, the city shall require the wetland alteration permit holder to satisfy long-term management requirements. (e). Mitigation Surety. To ensure that the proposed wetland replacement occurs, the city shall hold either a cash escrow or letter of credit equal to 110% of the current value of wetland credits on the open market. An additional escrow account shall be established to ensure that the 11 required monitoring occurs. The monitoring escrow shall be set at 110% of the current average monitoring expense as performed by an independent consultant. The monitoring and replacement escrows may be released incrementally as monitoring and replacement are successfully completed. The remaining escrow amount will be returned and the letter of credit terminated upon completion of the monitoring and approval by the Technical Evaluation Panel (TEP). Any interest earned by holding of a cash escrow shall be the property of the city. (t). Within the Minnehaha Creek Watershed District, 1:1 mitigation is required for excavation within wetlands. Sec. 20-417. Exemptions and no loss determinations. (a). Activities exempted by Minnesota Rules 8420.0122 or determined to result in no net loss of wetlands shall be exempted from the provisions of this ordinance. However, certificates of exemption or no loss must be obtained from the city prior to starting work. (b). A person conducting an activity in a wetland under an exemption shall ensure that: (1). Appropriate erosion and sediment control measures are taken to prevent sediment discharges from the site; (2). The activity does not block fish activity in a watercourse; and (3). The activity is conducted in compliance with all other applicable federal, state, and local requirements, including best management practices as listed in part 8420.0112, and water resource protection requirements established under M.S. Ch. 103H. Sec. 20-418. Variances. Variances from the requirements of this ordinance may be granted in accordance with the variance provisions of Article II, Division 3 of this chapter so long as the variances do not violate the Wetland Conservation Act and rules adopted under the Act. Sec. 20-419. Expiration and renewal of permit. (a). Unless otherwise specified by the city council, the permittee shall begin and complete the development authorized by the wetland alteration permit within one year after the date the council approves the permit application. (b). The permittee shall provide written notice to the city 24 hours prior to the commencement and completion of the permitted project. No project shall be deemed to have been completed until approved by the city after receipt of notice of completion. (c). If the permittee fails to commence work within the time specified in this section, the permit shall be void. The permittee may make a written application to the city council for an extension of the time to commence work, but only if the permittee submits the application prior to the date already established to commence work. The application of an extension shall state the reasons the permittee requires an extension. If the council does not extend the permit, the holder of the void permit may apply for a new permit. Sec. 20-420. Inspection of work. 12 The city may cause inspection of work for which a wetland alteration permit is issued, at the applicant's expense, to be made periodically during the course of such work and shall cause final inspection to be made following the completion of the work. Sec. 20-421. Enforcement procedures. (a). Violation of this article, wetland protection, or of the terms of a permit issued thereunder shall be a misdemeanor. (b). Any person who alters a wetland in violation of this article shall apply for a wetland alteration permit and shall pay a filing fee double the regular fee. The city council may require the violator to restore the wet!and or take other mitigative measures. Section 3. Section 20-1060 (2) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: Protect creek corridors, wetlands, and significant stands of mature trees through the use of careful site design; protective easements; sensitive alignment and design of roadways and utilities; incorporation of natural features; landscaping and massing of trees that enhance existing natural features and views; and the practices delineated in the City's Surface Water Management Plan. Section 4. Section 20-1061 (2) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: Preservation of the natural conditions found on each site to the greatest extent possible, through minimized removal of trees and other vegetation and soil, minimized site grading, and application of the practices found in the city's Surface Water Management Plan. Section 5. Section 20-1072 (a) ofthe City Code, City ofChanhassen, Minnesota, is hereby amended to read as follows: Where natural or existing topographic patterns contribute to the beauty or utility of a development, they shall be preserved to the greatest extent possible. Modification to topography will be permitted where and to the extent that it contributes to good design. All topographic modifications shall adhere to the practices delineated in the city's Surface Water Management Plan. Section 6. Section 20-1085 (3) of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: Protect creek corridors, wetlands, and significant stands of mature trees through the use of careful site design; protective easements; sensitive alignment and design of roadways/access and utilities; incorporation of natural features; landscaping and massing of trees that enhance existing natural features and views; and the practices delineated in the city's Surface Water Management Plan. 13 Section 7. The City Code, City of Chanhassen, Minnesota, is hereby amended by adding a section to be numbered 20-1408, which shall read as follows: Sec. 20-1408. Impervious surfaces. Creation of impervious surfaces within the bluff setback may contribute to bluff instability due to increased runoff and/or erosion. Impervious surfaces are prohibited within the bluff setback unless specifically authorized within this article. Section 8. Section 20-1551 (a) ofthe City Code, City ofChanhassen, Minnesota, is hereby amended to read as follows: Protect the Bluff Creek Corridor, wetlands, bluffs, and significant stands of mature trees through the use of careful site design, protective covenants, sensitive alignment and design of roadways and utilities, incorporation of natural features, landscaping, techniques outlined in the city's surface water management plan, and the practices delineated in the city's Surface Water Management Plan. Section 9. Section 20-1552 (b) of the City Code, City ofChanhassen, Minnesota, is hereby amended to read as follows: Preservation of the natural conditions found in the primary zone and to the greatest extent possible, preserving significant resources and minimizing impacts in the secondary zone through cluster development and other practices which minimize the removal of vegetation, minimize site grading, and application of practices found in the city's Surface Water Management Plan. Section 10. Section 20-1556 of the City Code, City of Chanhassen, Minnesota, is hereby amended to read as follows: To the greatest extent possible, all development shall minimize the amount of impervious surface by clustering development, using common access drives and utility corridors and minimizing building footprint size. Roads, walkways, bike trails, and parking areas must be designed parallel to natural contours with consideration to maintaining consolidated areas of natural topography and vegetation. Management of surface run-off caused by impervious cover shall be designed using practices delineated in the city's Surface Water Management Plan. Within the secondary zone of the BCO District, areas with average slopes exceeding 25 percent shall be preserved in their natural state and maintained as permanent open space. Areas with average slopes less than 25 percent but greater than ten percent shall not exceed an impervious surface coverage of 25 percent. Impervious coverage for areas where average slopes are less than ten percent shall be governed by the underlying zoning district. Section 11. Section 20-1561 (b) of the City Code, City ofChanhassen, Minnesota, is hereby amended to read as follows: Where possible, any disturbances of natural habitat areas within the secondary zone shall be avoided. Any alterations to the natural habitat within the secondary zone shall adhere to the practices delineated in the city's Surface Water Management Plan. 14 Section 12. This ordinance shall be effective immediately upon its passage and publication. PASSED AND ADOPTED this _ day of _, 200_, by the City Council of the City of Chanhassen, Minnesota Todd Gerhardt, City Manager Thomas A. Furlong, Mayor (Published in the Chanhassen Villager on ) 15