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G-1. 6845 Lake Harrison Circle Variance Request7700 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 7901 Park Place Phone: 952.227.1300 Fax: 952.227.1310 Senior Center Phone: 952.2271125 Fax: 952.227.1110 Website www.cl.chanhassen,mn.us MEMORANDUM TO: Todd Gerhardt, City Manager FROM: MacKenzie Walters, Assistant Planner DATE: October 10, 2016 SUBJ: Variance — 6845 Lake Harrison Circle Planning Case #2016-22 PROPOSED MOTION "The Chanhassen City Council denies the request to allow a 4.2 percent hardcover variance, and adopts the attached Findings of Fact and Decision." City Council approval requires a simple majority vote of the City Council. EXECUTIVE SUMMARY On September 20, 2016, the Planning Commission, acting as the Board of Appeals and Adjustments, reviewed and denied a variance request to build a paver patio around a swimming pool. The variance request included: 1) 33.14 percent hardcover variance (maximum permitted 25%). 2) 34.5 percent accessory structure rear lot coverage variance (maximum permitted 30%). 3) 15 -foot wetland setback variance (15 feet required). Since the Planning Commission meeting, the applicant submitted revised plans that reduced the impervious surface and eliminated the rear yard coverage and wetland setback variances. The following is a summary of the revisions: Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow Todd Gerhardt 6845 Lake Harrison Circle Variance Request October 10, 2016 Page 2 Comparison of Original and Alternative Proposals Ordinance Original Alternative Total Lot Coverage 25% 33.14% 29.2% Rear Yard Coverage 30% 34.5% 23.31% 40 feet or Wetland Setback 15 feet with im roved buffer 0 feet provided 15 feet Alternative Plan The proposed alterative is for a pool, a bar, fire pit, hot tub, and 800 square -foot patio. This proposal would exceed the property's 25 percent hardcover limit by 4.2 percent (759.25 square feet), and would result in 29.2 percent hardcover. The applicant proposes using an engineered paver patio system, retaining wall, and rain garden to mitigate the impact of the proposed pool area on the adjoining wetland. Please see the attached revised staff report on the alternative proposal for more comprehensive evaluation of the alternative proposal. Staff appreciates and recognizes the applicant's efforts to reduce the number of and intensity of variances required. The revised proposal does not exceed the property's rear lot accessory structure coverage limit, nor does it encroach upon the wetland setback. However, it still exceeds the property's 25 percent hardcover limit, and staff s concerns remain regarding the precedence and impacts of allowing homeowners to exceed hardcover limits utilizing pervious paver systems. g:\plan\2016 planning cases\2016-22 6845 lake harrison circle - var\6845 lake harrison executive surrarmy revised.doex Todd Gerhardt 6845 Lake Harrison Circle Variance Request October 10, 2016 Page 3 Due to concerns over the long-term efficiency of the proposed paver system, the precedent that would be set by allowing properties to exceed hardcover limits by utilizing pervious pavers, and the intent of the Single Family Residential District to limit lot coverage, Planning Staff recommends denial of the proposed alternative. The Water Resources Coordinator also recommends denial citing DNR guidelines, the condition of Riley Creek, and the anti - degradation requirements of the City's National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer Permit. Currently, the property has a deck located in the rear yard and conforms to all provisions of the Chanhassen City Code. All parcels in Block 2 of the Lake Harrison Subdivision where this property is located have a blanket 5 -foot front yard setback variance. No other variances have been issued within 500 feet of 6845 Lake Harrison Circle. In 2013, the property's previous homeowner applied for and received a building permit to construct a pool in the rear yard without a variance. The previous homeowner ultimately decided not to proceed with the project. Staff is recommending denial of the variance request. PLANNING COMMISSION SUMMARY The Planning Commission held a public hearing on the variance request on September 20, 2016. No members of the public spoke for or against the variance request. The Planning Commission inquired to the nature and feasibility of different pool, paver patio, and rain garden configurations. The Planning Commission expressed concern about the encroachment into the wetland setback and ability of the proposed system to successfully mitigate the amount of runoff which would be generated by the proposed pool area. The Planning Commission requested clarification of the city's policy on paver patios. Staff clarified that they were treated as hardcover and that no residential property in the city has been allowed to utilize them to reduce their impervious surface coverage. The Planning Commission voted unanimously 6-0 to deny the variance request for the pool area. The minutes of this meeting are Item D-2 of the October 10, 2016 City Council agenda. RECOMMENDATION Staff and the Planning Commission recommend that the City Council deny the variance request to allow a 4.2 percent hardcover variance, and adopt the attached Findings of Fact and Decision. Should the City Council approve the applicant's alternative proposal, it is recommended that the City Council adopt the following motion and the attached Findings of Fact and Decision: "The Chanhassen City Council approves the variance request to allow a 4.2 percent hardcover variance. The approved hardcover variance is subject to the following conditions: gAplan\2016 planning cases\2016-22 6845 lake harrison circle - var\6845 lake harrison executive summaryrevised.docx Todd Gerhardt 6845 Lake Harrison Circle Variance Request October 10, 2016 Page 4 1. The property's hardcover is not to exceed 29.2 percent. 2. Site specific infiltration data, at the proposed infiltration surface elevation must be provided. 3. The applicant must demonstrate that there will be a minimum separation to ground water of three (3) feet or more where the pervious pavement will be employed. 4. Hydrologic and hydraulic calculations must be provided and demonstrate that the permeable paver system and rain garden not only mitigates for the proposed increase, but can accommodate tributary drainage areas directed to them for the design storm. 5. The design of the permeable pavement system shall follow MN Stormwater Manual guidelines unless manufacturer specifications expressly recommend against those guidelines. This includes the typical cross-section. 6. Construction practices to be employed to avoid compaction of the subsurface including ripping the in situ soils to a minimum depth of 12 inches. 7. The design of the rain garden shall follow MN Stormwater Manual guidelines. 8. A maintenance and operations manual describing anticipated inspections, annual maintenance, responsible parties and annual reporting forms. 9. A detailed erosion prevention and sediment control plan shall be submitted to the city for review and approval. 10. The applicant must apply for and obtain permissions from Riley Purgatory Bluff Creek Watershed District and any other agency with legal jurisdiction over the site. 11. The site must comply with today's buffer standards. A buffer a minimum 25 feet in width must be established with 100 percent native vegetation, clearly indicated on the plan set, and demarcated with signage. A wetland buffer agreement shall be prepared and recorded against the property to comply with City Code Section 20-411(e). 12. All structures must be located outside of the secondary setback assuming buffers updated to current wetland protection requirements. 13. The applicant must apply for and receive a building permit from the city." ATTACHMENTS 1. Revised Planning Commission Staff Report (bold and strike -through format) 2. Letter from WRC (revised), dated October 4, 2016 3. Applicant's proposed alternative received October, 4, 2016. 4. Applicant's Letter of Appeal dated September 23, 2016. 5. Findings of Fact and Decision Denial. 6. Findings of Fact and Decision Approval. gAplan\2016 planning cases\2016-22 6845 lake harrison circle - var\6845 lake harrison executive summary_revised.docx Applicant CITY OF CHANHASSEN submitted a revised PROPOSED MOTION: PC DATE: September 20, 2016 CC DATE: October 10, 2016 REVIEW DEADLINE: October 18, 2016 CASE #: 2016-22 BY: MW, TJ are in bold and obsolete provisions nave been strucK tnr "The Chanhassen City Council Beffd of Appeals and Adjostments denies the varianee request to allow hafd,.ever to e-'eeed 25 pereei4 b5 844 a 4.2 percent hardcover variance, allow a de.aeked aecessei=JstFueture to exeeed the rear lot eavera lifnit f 30 pereent by 4.5 ent and allow va .. r J e ,. 15 feet re,l..etiaii iff the wetland Seth ek- and adopts the attached Findings of Fact and Decision." (Note: a motion for approval and appropriate findings of fact are also included at the end of the report.) SUMMARY OF REQUEST: The property owner is requesting a variance to allow them to add a 4300 800 -square foot permeable paver system around a proposed 40 feet feet pool in their rear yard. The Zoning Code allows this property to have a maximum hardcover of 4,481.75 square feet and the property currently has 4,441 square feet of hardcover. AdditieReffi�-, the pr-Opesed pool wouldafea eover 3 4.5pereent J f the fear yard and a veh 15 f :. et a the .e..- . fffd's wetland nett LOCATION: 6845 Lake Harrison Cir (PID 254170140) APPLICANT: Barb Hegenes 6845 Lake Harrison Cir Chanhassen, MN 55317 PRESENT ZONING: RSF 2030 LAND USE PLAN: Residential Low Density ACREAGE: .41 acres DENSITY: NA LEVEL OF CITY DISCRETION IN DECISION-MAKING: The City's discretion in approving or denying a variance is limited to whether or not the proposed project meets the standards in the Zoning Ordinance for a variance. The City has a relatively high )ugh. Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 2of10 level of discretion with a variance because the applicant is seeking a deviation from established standards. This is a quasi judicial decision. Notice of this public hearing has been mailed to all property owners within 500 feet. PROPOSAL/SUMMARY The property owner is requesting a variance to install a pool area in her rear yard. This pool area would include a 4300 800 -square foot paver patio system, 40 foot 18 fee pool, a bar, and a fire pit. The proposed patio system would exceed the property's hardcover limit of 4,481.75 square feet. (25 percent) by 4, 4 59.23 759.25 square feet. (8.44 4.2 percent). The City Code does not exempt permeable paver systems from hardcover calculations. The applicant plans to mitigate the proposed pool area's impact on the watershed by: 1) Building a 5 -foot boulder retaining wall which will tapper down to 2 feet at the southwest corner in the rear of the property outside of the existing an updated 20 25 - foot wetland buffer. The wall will help flatten the backyard. 2) Creating a rain garden in the southwest corner of the lot to mitigate and allow infiltration of the existing watershed coming down the south and west side of the yard. 3) Utilizing a permeable paver system that can capture and allow the infiltration of run off. The proposed paver system would include two and a half feet of 3/4" clear rock and 1" granite chips below the pavers. This retention area would capture the watershed from the north side of the house, part of the roof and approximately two thirds of run off generated by the back yard. The remaining run off would be directed into the two -foot -deep rain garden in the southwest corner of the lot. The rain garden will also handle any overflow from the permeable paver system through a release pipe installed below the pavers. This system may substantially reduce the watershed into the adjacent wetlands.; however-, it will also ee er 3 4.5 pereepA ofthe .e d and en eh 15 feet into the APPLICABLE REGULATIONS Chapter 1, General Provisions Section 1-2, Rules of Construction and Definitions Chapter 20, Article II, Division 3, Variances Chapter 20, Article XI. Wetland Protection Section 20-411. Placement of Structures Chapter 20, Article, XI. Wetland Protection Section 20-412. Buffer Strips Required Chapter 20, Article XIL "RSF" Single-family residential district Section 20-615. Lot requirements and setbacks. Chapter 20, Article, XXIII. General Supplemental Regulations Section 20-904. Accessory Structures. Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 3 of 10 BACKGROUND On March 7, 2008 the City of Chanhassen approved a permit for the construction of a single family home with an attached garage. The approved house, driveway, and associated sidewalks and stoops created 4,441 square feet of hardcover on a 17,927 -square foot lot. This resulted in a lot coverage of 24.77 percent. The Single -Family Residential District of the City Code states, "the maximum lot coverage for all structures and paved surfaces is 25 percent." At the time the City Code required a 20 -foot wetland buffer and 40 -foot structure setback from the edge of the buffer. The house was built in compliance with these provisions. On April 15, 2009 the City of Chanhassen approved a permit for the construction of 320 -square foot deck in the property's rear yard. The deck did not alter the property's hardcover. On May 19, 2011 the City of Chanhassen approved a permit for the construction of a 320 -square foot lower deck in the property's rear yard. The deck did not increase the property's hardcover. On September 18, 2013, the previous homeowner applied for a building permit to construct a pool in the rear yard. The permit was approved pending the removal of an amount of driveway surface equal to the amount of impervious pool apron to be installed and the use of wood decking to minimize the size of the impervious apron. The owner ultimately decided not to proceed with the project. On September 20, 2016 the Chanhassen Planning Commission voted unanimously to deny a variance request for a 1,500 -square foot permeable paver pool area. On September 23, 2016 the applicant appealed the decision of the Planning Commission to deny a variance request for a 1,500 -square foot permeable paver pool area. On October 4, 2016 staff received an alternative proposal for an 800 -square foot permeable paver pool area from the applicant. SITE CONDITIONS The property is zoned Single -Family Residential. This zoning district requires lots to be a minimum of 15,000 square feet, have front and rear yard setbacks of 30 feet, side yard setbacks of 10 feet, and limits hardcover to a maximum of 25 percent of lot area. General provisions in the City Code prevent accessory structures from covering more than 30 percent of the rear yard. The property is located within the Shoreland Management District for Lake Harrison which limits impervious surface to 25 percent of lot area. Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 4of10 A blanket 5 -foot front yard variance for Block 2 was approved with the subdivision that created this parcel (Planning Case 2005-14) A wetland classified as Manage 1 lies to the east of the property and a wetland buffer encompasses the last 20 feet of the rear yard. Since this lot was created prior to May 14, 2007 there is a 40 -foot structure setback from the wetland buffer. The home owner has the option of reducing that setback by 20 feet for accessory structures if they create a buffer strip as provided in Section 411-11(e). See the attached letter from the Water Resources Coordinator for a more detailed discussion of the wetland setbacks that apply to this property. The lot is 17,927 square feet and has 4,441 square feet of impervious surface resulting in 24.77 percent lot coverage. The house has a 25 -foot front yard setback, a 13.10 -foot south side yard setback, a 10 -foot north side yard setback, and a 70 -foot rear yard setback from the rear lot line (50 -foot setback from the wetland buffer). The current deck is also setback 70 -feet from the rear yard (50 -foot setback from the wetland buffer). The existing house and accessory structures comply with all relevant provisions of the City Code. Lake Harris Subdivision: Block 1: The houses located on Block 1 tend to be situated on larger parcels, typically half an acre or larger. Those located on Lots 2 & 4, Block 1 are located on smaller lots and are close to the 25 percent hardcover limit. Block 2: The four houses located on Lots 1-4, Block 2 are all either at their 25 percent maximum lot coverage or within 1.3 percent of it. Of these four houses one was required to remove installed hardcover that was in excess of the 25 percent allowed by the City Code, and another had to revise a proposed project in order to avoid exceeding the 25 percent limit. Lots 2-4, Block 2 feature relatively large houses placed on parcels of approximately 18,000 square feet. The Lot 1, Block 2 has substantially larger lot of 26,869 square feet. Those located on Lots 5-10, Block 2 tend to be smaller homes located on lots between 20,306 square feet and 26,901 square feet. Block 3: The lots that comprise Block 3 tend to be larger; however, Lots 1-4, Block 3 are smaller lots with relatively large houses and are all at or within 1.3 percent of the 25 percent hardcover limit. Variances within 500 feet: Blanket Subdivision Variance: All parcels on Block 2 of the Lake Harris Subdivision have a 5 - foot front yard variance. (Planning Case 2005-14) Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 5 of 10 No other variances could be found within 500 feet of 6845 Lake Harrison Cir. Hardcover issues: Two properties on Block 2 have had to either alter proposed projects or remove existing hardcover in order to comply with the zoning district's 25 percent hardcover limit. Block 1 .,J Lake Harrison Subdivision % }YL 4 A ; t ANALYSIS Stormwater management One of the goals of the City's hardcover ordinance is to limit and manage the amount of runoff generated by developments. The ordinance limits properties in Single Family Residential Districts (RSF) to a maximum lot coverage of 25 percent. The property is also located within the Lake Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 6 of 10 Harrison Shoreland Management District which limits lots to a maximum of 25 percent impervious surface. As noted in the letter from the Water Resource Coordinator the 25 percent cap was established based on studies showing the link between impervious surface coverage and negative impacts on water quality. The City considers paver patios and other pervious pavement systems to constitute hardcover contributing to lot coverage. The rationale behind this determination is that the efficacy of these systems depends heavily on their design and proper maintenance. If these systems are not properly designed and maintained they rapidly lose their permeable characteristics and function the same as traditional impervious surfaces. The City lacks a mechanism for monitoring and enforcing the maintenance of pervious paver systems. It should also be noted, again from the Water Resource Coordinator's letter, that the DNR does not recognize the use of impervious pavers to allow developments exceed the 25 percent impervious surface cap. The proposed paver patio system is engineered so that surface water will drain through the voids between pavers and into the infiltration system beneath the patio. hi the event that the surface water generated by a rain event exceeds the system's infiltration capacity drain tiles are placed just beneath the pavers in order to divert the excess into the rain garden. The paver patio system will be integrated with a retaining wall, grading improvements, and the aforementioned rain garden to further mitigate the pool area's impact on the amount of runoff generated by the property. The proposed paver patio system appears to be designed in line with best management practices. More information would be required to accurately project its efficacy. The long term viability of the system will depend on the current and potential future homeowners performing proper maintenance. Without proper maintenance the spaces between the pavers can rapidly become filled in and clogged. When this happens, those sections of the paver patio system will behave as impervious surfaces. If the functionality of 2—.7 5.2 percent of the proposed paver system became impaired it would be functionally equivalent to allowing the property to exceed its hardcover limit with conventional surfaces. Due to these concerns, most communities either count paver patio systems as impervious surface, like Chanhassen, or use a set ratio or credit system to evaluate how they contribute to a parcel's hardcover. Replacing the proposed paver patio system with a detached deck or expanding the existing lower deck would allow for a similar use of the rear yard as the proposed paver patio system without requiring a hardcover variance. Viewscape The City's hardcover restrictions are also intended to ensure that residential neighborhoods have a significant amount of open space. Residential districts with zoning that allows for higher lot coverage percentages than RSF's 25 percent are those where significant amounts of upland are preserved or created as permanent open space to balance out the higher hard surface and lot coverage on individual lots. In all lew density residential district, See fien 20 904 of the City Code Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 7of10 limits Eletae-hed aeeessery struettiFes to eec-up54ng no more them 3 0 pement E)f a par -eel's rear 5 - The proposed poo1 area weeld 2,200 square feet F the lot's6,435 square feet r-eaFyard .�nulling inn n«.1 n of 34 5 e...t While the aet" eeverage of the lot's rear- n«.l uwu..b..w..,wryw...w e wetdd be 4.5 pereeR4 above the difeshold established by the City Code, the Nisual invaet woul d he the rvaf yard is lee-Wd behind the heiise, and the pr-esenee of the retaiiiing wall m4ii� efeates the - intuitive N4s" J of the «Jn«.7 The proposed landscaping andrelatWely largehouseY Y landscaping b loss of open space f « all but the adj eei# ..«..,.e«t., n..,.,e«s Redueifig the pool area's size by 269.5 squafe feet. would allow it to be built in eornplianeewi& 9 eetion 20 90 4, btA would still plaee the property , 189.75 n e F et The proposed paver patio area would be 759.25 square feet over the property's 25 percent structure and paved surface lot coverage limit for a total lot coverage of 29.2 percent. As was noted earlier, this limit was created with the dual intent of managing stormwater and creating visually appealing neighborhoods by preserving open spaces. Y y- S. - MWIMM RON II Y. W Y. Y. Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 8 of 10 .fWORN ram pri're"MIN!!'i5. r Up. RM I RIM"Mr.W.WN... lRVIMPU M.PMR-ly-T.RSRl IpsM_ E7Srrn RMWR-f.Rr*ss. . 00 01111 SUMMARY The proposed pool area would place the property 1 ,^� 759.25 square feet over its 4,481.75 - square foot. hardcover limit, 269.5 square feet ,...eco, re—arlot neeessery straeture eoverage limit and would be loeated 15 feet .,.al.in the pr-epeA ',.wetland setl.,,a.. The applicant proposes to mitigate these impacts through the creation of a paver patio system which, if properly designed and maintained, may substantially reduce the amount of run off generated by the impervious surface. A significant number of the surrounding properties are at or within 2 percent of the 25 percent hardcover limit, and two have had projects sent back for revision or code enforcement action taken to prevent them from exceeding the zoning district's hardcover maximum. To date, other than the Block 2 blanket 5 -foot setback, no variances have been given to any properties within 500 feet of the applicant. Currently there is a single family home located on this property which is the primary use for the RSF district. The applicant has the ability to construct other accessory structures in the rear yard, and a permit was previously issued for the construction of a pool area in the rear yard that did not require a variance. "The Chanhassen Beard of Appeals and ^ ,,;,,,,tme,.t„ City Council denies the variance request to allow hafdeaver te exeeed 25 pefeeat b5,8.14 a 4.2 percent, alhm a aetac ea e struetwe to &ieeed the rear lot eaver-age limit of 30 pereepA by 4.5 pereefft, and allew a 15 foot .eduet:en i the ....'and Seth e1. hardcover variance, and adopts the attached Findings of Fact and Decision." Should the Planning Commission approve the variance request to exeeea .alwIyea 1,ar, eoye. but 00 01111 Currently there is a single family home located on this property which is the primary use for the RSF district. The applicant has the ability to construct other accessory structures in the rear yard, and a permit was previously issued for the construction of a pool area in the rear yard that did not require a variance. "The Chanhassen Beard of Appeals and ^ ,,;,,,,tme,.t„ City Council denies the variance request to allow hafdeaver te exeeed 25 pefeeat b5,8.14 a 4.2 percent, alhm a aetac ea e struetwe to &ieeed the rear lot eaver-age limit of 30 pereepA by 4.5 pereefft, and allew a 15 foot .eduet:en i the ....'and Seth e1. hardcover variance, and adopts the attached Findings of Fact and Decision." Should the Planning Commission approve the variance request to exeeea .alwIyea 1,ar, eoye. but Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 9of10 wet4and buff. ..,.F1 ael it is recommended that the planning Commission adopt the following motion and attached Finding of Fact and Decision: "The Chanhassen Board of Appeals and Adjustments approves the variance request to allow 1,,..-,1,.,.ver tea eed 25 _ epA b5,3 a 4.2 percent hardcover variance, but denies the .. a by 4.5 pe epA and for „ 15 c et _,.dee-tien iii the, ;.A,, efl-4 Ad buff .. setb & The approved hardcover variance is subject to the following conditions:" 1. The property's hardcover is not to exceed 28 29.2 percent 2. Site specific infiltration data, at the proposed infiltration surface elevation must be provided. 3. The applicant must demonstrate that there will be a minimum separation to ground water of three (3) feet or more where the pervious pavement will be employed. 4. Hydrologic and hydraulic calculations must be provided and demonstrate that the permeable paver system and rain garden not only mitigates for the proposed increase, but can accommodate tributary drainage areas directed to them for the design storm. 5. The design of the permeable pavement system shall follow MN Stormwater Manual guidelines unless manufacturer specifications expressly recommend against those guidelines. This includes the typical cross-section. 6. Construction practices to be employed to avoid compaction of the subsurface including ripping the in situ soils to a minimum depth of 12 inches. 7. The design of the rain garden shall follow MN Stormwater Manual guidelines. 8. A maintenance and operations manual describing anticipated inspections, annual maintenance, responsible parties and annual reporting forms. 9. A detailed erosion prevention and sediment control plan shall be submitted to the city for review and approval. 10. The applicant must apply for and obtain permissions from Riley Purgatory Bluff Creek Watershed District and any other agency with legal jurisdiction over the site. 11. The site must comply with today's buffer standards. A buffer, minimum 25 feet in width must be established with 100 percent native vegetation, clearly indicated on the plan set, demarcated with signage, and recorded with the property. 12. All structures must be located outside of the secondary setback assuming buffers updated to current wetland protection requirements. 13. The applicant must apply for and receive a building permit from the City Planning Commission 6845 Lake Harrison Cir September 20, 2016 Page 10 of 10 ATTACHMENTS 1. Finding of Fact and Decision Denial 2. Finding of Fact and Decision Approval 3. Development Review Application 4. Registered Land Survey 5. Landscape Plans 6. Letter from WRC 7. Memo from RPBCWD 8. Affidavit of Mailing of Public Hearing Notice CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA FINDINGS OF FACT AND DECISION (DENIAL) IN RE: Application of Barb Hegenes for a variance to allow hardcover to exceed 25 percent by 8.14 percent, allow a detached accessory structure to exceed the rear lot coverage limit of 30 percent by 4.5 percent, and allow a 15 -foot reduction in the wetland buffer setback on property zoned Single - Family Residential District (RSF)-Planning Case 2016-22. On September 20, 2016, the Chanhassen Planning Commission, acting as the Board of Appeals and Adjustments, met at its regularly scheduled meeting to consider the application. The Planning Commission conducted a public hearing on the proposed variance preceded by published and mailed notice. The Board of Appeals and Adjustments makes the following: FINDINGS OF FACT 1. The property is currently zoned Single -Family Residential District (RSF). 2. The property is guided in the Chanhassen Comprehensive Plan for Residential Low Density. 3. The legal description of the property is: Lot 2, Block 2, Lake Harrison 4. Variance Findings —Section 20-58 of the City Code provides the following criteria for the granting of a variance: a. Variances shall only be permitted when they are in harmony with the general purposes and intent of this Chapter and when the variances are consistent with the comprehensive plan. Finding: The subject site is zoned Single -Family Residential District. The purpose of the request is to provide an area for family recreation in the rear yard. While this type of use is in harmony with the intent of the RSF District, permitting a pool area of this size is not in harmony with the intent of the district's coverage requirements, both as they pertain to stormwater management and the aesthetics of the neighborhood. No other property in the neighborhood has been allowed to exceed the RSF District's hard cover limit or the restrictions on the amount of the rear yard which may be covered by an accessory structure. The property currently has decks which allow for the use and enjoyment of the rear yard, and does not require the proposed pool area to allow the utilization of the rear yard. The property is also located within Lake Harrison's shoreland management district. Permitting properties within the shoreland management district to have impervious surface in excess of 25 percent is not in harmony with shoreland management district's goal of protecting and preserving water quality. Allowing an accessory structure within the required wetland setback is not in harmony with the ordinance's goal of protecting wetland buffers by ensuring a minimum distance between yard features and the start of the buffer. b. When there are practical difficulties in complying with the zoning ordinance. "Practical difficulties," as used in connection with the granting of a variance, means that the property owner proposes to use the property in a reasonable manner not permitted by this Chapter. Practical difficulties include, but are not limited to, inadequate access to direct sunlight for solar energy systems. Finding: The property currently complies with the City Code. The owner has options within the code for creating a rear yard family area including expanding the existing decks, constructing a detached deck in the rear yard, building a pergola, and other similar structures that would not increase the lot's hardcover. Historically, a permit to build a pool was issued for this property without any variance being requested or granted. Requesting an additional 1,459.25 sq. ft. of impervious surface to construct a pool area is not a practical difficulty in meeting the City Code. Requesting to encroach into the required wetland setback is also not the result of a practical difficultly in meeting the City Code. The rear yard is large enough that a functional family area could be created while maintaining the required wetland buffer setback. C. That the purpose of the variation is not based upon economic considerations alone. Finding: The stated intent is to create a family oriented pool area in the rear yard. Although the proposed pool area would increase the property's value, the request does not appear to based upon economic considerations. d. The plight of the landowner is due to circumstances unique to the property not created by the landowner. Finding: When the house was built all of the existing regulations regarding impervious surfaces and lot coverage were in place. The lot is larger than the minimum lot size required in the RSF district. The inability to increase the amount of impervious surface is due to the fact that the house and driveway were designed and built to cover 24.77 percent of the lot, not due to any unique feature of the lot. The inability to construct the proposed accessory structure is the result of its proposed design. The wetland buffer setback does limit the amount of developable rear yard; however, the Block 2 of the subdivision was granted a 5 -foot front yard setback variance which mitigates its impact. The house was situated on the property in order to allow for a viable rear yard given the wetland setbacks that were in place at the time of construction. Section 20-411(e) allows for an increase in the usable rear yard in exchange for improved wetland buffers. Accessory structures can be built in the rear yard that conform to the required setback or the setback which could be achieved through Section 20-411(e). e. The variance, if granted, will not alter the essential character of the locality. Finding: Currently no property in the neighborhood has been allowed to exceed the RSF district's impervious surface, lot coverage, and wetland setbacks. Allowing a property to cover a large portion of their rear yard with paver patios would significantly alter the visual impact and character of the neighborhood. Variances shall be granted for earth sheltered construction as defined in Minnesota Statutes Section 216C.06, subdivision 14, when in harmony with this Chapter. Finding: This does not apply to this request. 5. The planning report #2016-22, dated September 20, 2016, prepared by MacKenzie Walters, is incorporated herein. DECISION "The Chanhassen Board of Appeals and Adjustments denies the variance request to allow hardcover to exceed 25 percent by 8.14 percent, allow a detached accessory structure to exceed the rear lot coverage limit of 30 percent by 4.5 percent, and allow a 15 -foot reduction in the wetland setback." ADOPTED by the Chanhassen Planning Commission this 20a' day of September, 2016. CITY OF CHANHASSEN BY: Chairman CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA FINDINGS OF FACT AND DECISION (APPROVAL) IN RE: Application of Barb Hegenes for a variance to allow hardcover to exceed 25 percent by 8.14 percent, allow a detached accessory structure to exceed the rear lot coverage limit of 30 percent by 4.5 percent, and allow a 15 -foot reduction in the wetland buffer setback on property zoned Single - Family Residential District (RSF)-Planning Case 2016-22. On September 20, 2016, the Chanhassen Planning Commission, acting as the Board of Appeals and Adjustments, met at its regularly scheduled meeting to consider the application. The Planning Commission conducted a public hearing on the proposed variance preceded by published and mailed notice. The Board of Appeals and Adjustments makes the following: FINDINGS OF FACT 1. The property is currently zoned Single -Family Residential District (RSF). 2. The property is guided in the Chanhassen Comprehensive Plan for Residential Low Density. 3. The legal description of the property is: Lot 2, Block 2, Lake Harrison 4. Variance Findings —Section 20-58 of the City Code provides the following criteria for the granting of a variance: a. Variances shall only be permitted when they are in harmony with the general purposes and intent of this Chapter and when the variances are consistent with the comprehensive plan. Finding: The subject site is zoned Single -Family Residential District. The purpose of the request is to provide an area for family recreation in the rear yard. This use is in harmony with the intent of the RSF District. The district's coverage requirements are designed to manage both stormwater and the visual impact of developments. While the proposed paver system will mitigate the impact on stormwater generation, it will not address the "paved backyard" appearance created by exceeding the 30 percent rear yard coverage maximum for accessory structures. Accessory structures exceeding this limit are not in harmony with the intent of the RSF district. The property is located within Lake Harrison's shoreland management district. Permitting more than 25 percent hardcover in a shoreland management district threatens the district's goal of protecting and preserving water quality; however, the proposed paver patio system can mitigate this impact. Allowing an accessory structure within the required wetland setback is not in harmony with the ordinance's goal of protecting wetland buffers by ensuring a minimum distance between yard features and the start of the buffer. b. When there are practical difficulties in complying with the zoning ordinance. 'Practical difficulties," as used in connection with the granting of a variance, means that the property owner proposes to use the property in a reasonable manner not permitted by this Chapter. Practical difficulties include, but are not limited to, inadequate access to direct sunlight for solar energy systems. Finding: Given the existing house configuration the applicant could not install a reasonable pool area within the confines of the zoning code's hardcover restrictions; however, a reasonable pool area could be installed in compliance with the restrictions on accessory structure lot coverage and the wetland buffer setback. c. That the purpose of the variation is not based upon economic considerations alone. Finding: The stated intent is to create a family oriented pool area in the rear yard. Although the proposed pool area would increase the property's value, the request does not appear to based upon economic considerations. d. The plight of the landowner is due to circumstances unique to the property not created by the landowner. Finding: Market trends at the time of the house's construction favored large houses with three car garages. Given the dimensions of the lot and location of the rear wetland the property simply does not have enough acreage to allow for reasonable residential use while maintaining less than 25 percent lot coverage. The lot's lay out and existing blanket 5 -foot front yard setback variance allows adequate rear yard space for a pool area. e. The variance, if granted, will not alter the essential character of the locality. Finding: The house immediately north has a pool and many other properties in the neighborhood have recreational areas in their rear yards. Due to the location of the proposed pool area, house placement, and proposed screening the project's impact on the neighborhoods will be minimal. f Variances shall be granted for earth sheltered construction as defined in Minnesota Statutes Section 216C.06, subdivision 14, when in harmony with this Chapter. Finding: This does not apply to this request. 5. The planning report #2016-22, dated September 20, 2016, prepared by MacKenzie Walters, is incorporated herein. DECISION The Chanhassen Board of Appeals and Adjustments approves the variance request to allow hardcover to exceed 25 percent by 3 percent, but denies the variance requests for a detached accessory structure to exceeding the rear lot coverage limit of 30 percent by 4.5 percent and for a 15 -foot reduction in the wetland setback. The approved hardcover variance is subject to the following conditions:" 1. The property's hardcover is not to exceed 28 percent 2. Site specific infiltration data, at the proposed surface elevation must be provided. 3. The applicant must demonstrate that there will be a minimum separation to ground water of three (3) feet or more. 4. Hydrologic and hydraulic calculations must be provided and demonstrate that the permeable paver system and rain garden not only mitigates for the proposed increase, but can accommodate tributary drainage areas directed to them for the design storm. 5. The design of the permeable pavement system shall follow MN Stormwater Manual guidelines unless manufacturer specifications expressly recommend against those guidelines. This includes the typical cross-section. 6. Construction practices to be employed to avoid compaction of the subsurface including ripping the in situ soils to a minimum depth of 12 inches. 7. The design of the rain garden shall follow MN Stormwater Manual guidelines. 8. A maintenance and operations manual describing anticipated inspections, annual maintenance, responsible parties and annual reporting forms. 9. A detailed erosion prevention and sediment control plan shall be submitted to the city for review and approval. 10. The applicant must apply for and obtain permissions from Riley Purgatory Bluff Creek Watershed District and any other agency with legal jurisdiction over the site. 11. The site must comply with today's buffer standards. A buffer, minimum 25 feet in width must be established with 100 percent native vegetation, demarcated with signage, and recorded with the property. 12. All structures must be located outside of the secondary setback assuming buffers updated to current wetland protection requirements. 13. The applicant must apply for and receive a building permit from the City ADOPTED by the Chanhassen Planning Commission this 20th day of September, 2016. CITY OF CHANHASSEN BY: Chairman COMMUNITY DEVELOPMENT DEPARTMENT Planning Division – 7700 Market Boulevard Mailing Address – P.O. Box 147, Chanhassen, MN 55317 Phone: (952) 227-1300 / Fax: (952) 227-1110 0 CITY OF CAANHASSEN �[ APPLICATION FOR DEVELOPMENT REVIEW Submittal Date: v PC Date: CC Date: 60 -Day Review Date: (Refer to the appropriate Application Checklist for required submittal information that must accompany this application) ❑ Comprehensive Plan Amendment ... ......... _.......... $600 ❑ Minor MUSA line for failing on-site sewers ..... $100 ❑ Conditional Use Permit (CUP) ❑ Single -Family Residence ................................ $325 ❑ All Others......................................................... $425 ❑ Interim Use Permit (IUP) ❑ In conjunction with Single -Family Residence.. $325 i lots) ❑ All Others......................................................... $425 ❑ Rezoning (REZ) ❑ Consolidate Lots..............................................$150 ❑ Planned Unit Development (PUD)..................$750 ❑ Minor Amendment to existing PUD ................. $100 (includes $450 escrow for attorney costs)' ❑ All Others......................................................... $500 ❑ Sign Plan Review ................................................... $150 ❑ Site Plan Review (SPR) (Additional recording fees may apply) ❑ Administrative.................................................. $100 $200 ❑ Commercial/Industrial Districts' ......................$500 ❑ Single -Family Residence ............................... Plus $10 per 1,000 square feet of building area: ❑ All Others ....................................................... (_ thousand square feet) ❑ Zoning Appeal ...................................................... $100 Include number of existing employees: "Include number of new employees: ❑ Residential Districts ............................... I........ $$500 Plus $5 per dwelling unit (—_ units) ❑ Subdivision (SUB) ❑ Zoning Ordinance Amendment (ZOA)................. $500 NOTE: When multiple applications are processed concurrently, the appropriate fee shall be charged for each application. ❑✓ Notification Sign (City to install and remove) ............... ............................................. ................. .......J................................ $200 ❑✓ Property Owners' List within 500' (City to generate after pre -application meeting) .............................!............. $3 per address ( addresses) Escrow for Recording Documents (check all that apply) .................................................... .......... $50 per document ❑ Conditional Use Permit ❑ Interim Use Permit ❑ Site Plan Agreement ❑ Vacation ❑✓ Variance ❑ Wetland Alteration Permit ❑ Metes & Bounds Subdivision (3 docs.) ❑ Easements {_ easements) TOTAL FEE: Description of Proposal: Property Address or Location: Parcel #: 25-4170140 Section 2: Required Information 6845 Lake Harrison Circle, Chanhassen, MN 55317 Legal Description: Lot 2, Block 2, LAKE HARRISON Total Acreage: 17,927.00 Wetlands Present? 0 Yes ❑ No Present Zoning: Single -Family Residential District (Rs Requested Zoning: Not Applicable El Present Land Use Designation: Residential Low Dens Requested Land Use Designation: Not Applicable El Existing Use of Property: Residence and residential yard ❑ Check box is separate narrative is attached. ❑ Create 3 lots or less ........................................$300 ❑ Create over 3 lots .......................$600 + $15 per lot i lots) ❑ Metes & Bounds (2 lots)..................................$300 ❑ Consolidate Lots..............................................$150 ❑ Lot Line Adjustment.........................................$150 ❑ Final Plat ..........................................................$700 (includes $450 escrow for attorney costs)' Additional escrow may be required for other applications through the development contract. ❑ Vacation of Easements/Right-of-way (VAC)........ $300 (Additional recording fees may apply) 21 Variance (VAR) .................................................... $200 ❑ Wetland Alteration Permit (WAP) ❑ Single -Family Residence ............................... $150 ❑ All Others ....................................................... $275 ❑ Zoning Appeal ...................................................... $100 ❑ Zoning Ordinance Amendment (ZOA)................. $500 NOTE: When multiple applications are processed concurrently, the appropriate fee shall be charged for each application. ❑✓ Notification Sign (City to install and remove) ............... ............................................. ................. .......J................................ $200 ❑✓ Property Owners' List within 500' (City to generate after pre -application meeting) .............................!............. $3 per address ( addresses) Escrow for Recording Documents (check all that apply) .................................................... .......... $50 per document ❑ Conditional Use Permit ❑ Interim Use Permit ❑ Site Plan Agreement ❑ Vacation ❑✓ Variance ❑ Wetland Alteration Permit ❑ Metes & Bounds Subdivision (3 docs.) ❑ Easements {_ easements) TOTAL FEE: Description of Proposal: Property Address or Location: Parcel #: 25-4170140 Section 2: Required Information 6845 Lake Harrison Circle, Chanhassen, MN 55317 Legal Description: Lot 2, Block 2, LAKE HARRISON Total Acreage: 17,927.00 Wetlands Present? 0 Yes ❑ No Present Zoning: Single -Family Residential District (Rs Requested Zoning: Not Applicable El Present Land Use Designation: Residential Low Dens Requested Land Use Designation: Not Applicable El Existing Use of Property: Residence and residential yard ❑ Check box is separate narrative is attached. APPLICANT OTHER THAN PROPERTY OWNER: In signing this application, 1, as applicant, represent to have obtained authorization from the property owner to file this application. I agree to be bound by conditions of approval, subject only to the right to object at the hearings on the application or during the appeal period. If this application has not been signed by the property owner, I have attached separate documentation of full legal capacity to file the application. This application should be processed in my name and I am the party whom the City should contact regarding any matter pertaining to this application. I will keep myself informed of the deadlines for submission of material and the progress of this application. further understand that additional fees may be charged for consulting fees, feasibility studies, etc. with an estimate prior to any authorization to proceed with the study. I certify that the information and exhibits submitted are true and correct. Name: Outdoor Excapes Contact: Mark Hauri Address: 2345 Daniels St., Long Lake, MN 55356 Phone: (952) 926-6899 City/State/Zip: Long Lake, MN 55356 Cell: (651) 503-6585 Email: mhauri@outdoorexcapes.com Fax: Signature: Date: 8/18/16 PROPERTY OWNER: In signing this application, I, as property owner, have full legal capacity to, and hereby do, authorize the filing of this application. I understand that conditions of approval are binding and agree to be bound by those conditions, subject only to the right to object at the hearings or during the appeal periods. I will keep myself informed of the deadlines for submission of material and the progress of this application. I further understand that additional fees may be charged for consulting fees, feasibility studies, etc. with an estimate prior to any authorization to proceed with the study. I certify that the information and exhibits submitted are true and correct. Name: Barb Hegenes Contact: Address: 6845 Lake Harrison Circle Phone: City/State/Zip: Chanhassen, MN 55317 Cell: (612) 730-3804 Email: bjh.evan@gmail.com Fax: Signature: I5e&Arm,' &4AAI t Date: 8/18/16 This application must be completed in full and must be accompanied by all information and plans required by applicable City Ordinance provisions. Before filing this application, refer to the appropriate Application Checklist and confer with the Planning Department to determine the specific ordinance and applicable procedural requirements and fees. A determination of completeness of the application shall be made within 15 business days of application submittal. A written notice of application deficiencies shall be mailed to the applicant within 15 business days of application. PROJECT ENGINEER (if applicable) Name: Contact: Address: Phone: City/State/Zip: Cell: Email: Fax: Section 4: Notification Information Who should receive copies of staff reports? *Other Contact Information: Property Owner Via: 0 Email Q Mailed Paper Copy Name: Q Applicant Via: Q Email ❑ Mailed Paper Copy Address: ❑ Engineer Via: ❑ Email ❑ Mailed Paper Copy City/State/Zip: ❑ Other* Via: ❑ Email ❑ Mailed Paper Copy Email: TRUCTIONS TO APPLICANT: Complete all necessary form fields, then select SAVE FORM to save a copy to your ice. PRINT FORM and deliver to city along with required documents and payment. SUBMIT FORM to send a digital L y to the city for processing (required). SAVE FORM PRINT FORM SUBMIT FORM Variance Request for Barb Hegenes 6845 Lake Harrison Circle, Chanhassen, MN 55317 REQUESTING A VARIANCE TO USE PERMEABLE PAVERS TO MITIGATE RUN-OFF AND HARDCOVER In 2016, Barb Hegenes purchased the house and property at 6845 Lake Harrison Circle in Chanhassen from the original owner who had previously built the house. She has contracted with Outdoor Excapes and Landscape Designer Mark Hauri to create a pool area in her backyard that will be a space for her and her whole family to come together and enjoy. The property which is 17,927 square feet backs up to a wetland area. The current hardcover on the lot currently is 24.77% (4,441 sq.ft) which is calculated by: the building/front stoop and pad (3,521 sq.ft) and the front driveway and sidewalk (920 sq.ft). Currently, there is no hardcover area in the backyard. Due to the nature of the existing slope of the back, side yards, and half of the roofs watershed, all the rain water that hits these areas currently runs off directly into the wetland area. The backyard and side yard slope, although not excessive, does not allow for much infiltration in these areas before it runs off. Our main goals with this residential project and variance request are to work with the Riley Purgatory Bluff Creek Watershed District, the City of Chanhassen's engineers, the DNR, and Barb Hegenes to create a pool and backyard environment that will: 1) build a 5' boulder wall along the back property line (tapering down to 2' at the southwest corner), outside of the 2(' Wetland Buffer, to help flatten the backyard, 2) mitigate the current watershed directly into the bluff by creating a permeable paver area that can capture and allow infiltration instead of direct run off into the wetland area, 2) create a rain garden in the southwest corner of the lot to mitigate and allow infiltration of the existing watershed coming down the south and west side of the yard, 3) request a variance to allow for an additional 1,500 square feet of permeable pavers around the proposed 40' x 18' pool. Our permeable paver system will include two and a half feet of %" clear rock and 1" of granite chips below the permeable pavers. This retension area will capture the watershed from the north side of the house, half of the roofs watershed, and approximately two thirds of the backyard's watershed. The remaining roofs watershed and backyard drainage will be graded to direct it into a two foot deep rain garden in the southwest corner of the lot. This depression will also be able to handle overflow (if any) from the permeable paver system which will have a release pipe installed just below the pavers. These systems, working in conjunction with each other, will alleviate virtually all the watershed into the current wetlands by creating a flatter yard and allowing water to be pretreated and infiltrate into the soil instead of running directly into these said wetlands. To accomplish this project and request for added hardcover using permeable pavers, Barb and Outdoor Excapes will work directly with the City of Chanhassen and the Riley Purgatory Bluff Creek Watershed's engineers to ensure that the engineering and installation of this pool, permeable system, and landscape are accurate and done in accordance with the best practices and engineering standards for these areas. Outdoor Excapes will also work with the Watershed District to post 3 wetland setback signs, currently not installed, to make sure both the current and/or potential future owner(s) understand and visually see the 20' wetland setback area. ur^ RECEIVED 5Ef. AUG 19 ZU16 CHANHASSEN PLANNING DEPT r- 0 1 IC. Lot 2, l3ESORI2, LA #ELEVATIONS PROVIDED BY CLIENT# ASHUILT 5"URVEY 9yo2ft''We Lot 2, Block 2, LAKE HARRISON, according to. the Elevations nrovided.bv client recorded plot thereo`, Carver County, Minnesoa. *BUILDING DIMENSIONS DO NOT REFLECT BRICK FACING* Garage Floor = 999.43 at overhead door) *BUILDING DIMENSIONS SHOWN REFLECT LOWER LEVEL PLAN= 6845 Lake Harrison Circle � � � 9 ( BuildingPermit Number 2008-003-04 Top of Foundation Wall = 1001.844 EXISTING HOUSE /`� i DATED FEBRUAP,Y 13, 2008 a, I FFE 99679 0 Lowest Floor = 993.42(9 Foot Basemen f) 995.56 s9zo + = i0 / #CURB AND GUTTER APE EXIS77NG# r Y UT/LI T/ES ARE EXISTING* x R, T o o � _ o �* Lot Area = 17,927 sq. ft.zs"'K ` x = °"ry 6V�¢od3'1 �" m " „ u y� ` Building, stoop and pad = 3,521 sq. ft. 1--- — _ — _ _ _ \ er 165.31 x m y'2 978 98 I Driveway and sidewalk = 920 sq. ft. 0 I \7- �' ';^ o, I Impervious area = 4,441 sq. ft. /24.77 % of total Lot area I 8oULOER RETAINING 9g °. NL —' n I WALL -3!r i=x2FL+- 995.8 - _ �1 SI�•1 m -' \ 0 �l e•' i sg j 20° •oo �g9 Y` 4 ,� __i a I 10 ` j - Denotes iron monument found 40.00 p a1i. O Denotes iron monument set APPS®'��D I I LID Bearings based on assumed datum. BY. 68BW 'ao J/+ DEPT.: Pias- ,ate• .,il. DATE: �'F OFCHANHASSEo' 15 W X y 3� �� 2m N ,��1. O °� WE ND R i 5 i`? 11 RECEIVED F? fQ Ill ,1 - r :0 BY: 111, i 'r —r ,— '� —, w W .90. �Q I X �. .t r , , e t ,' i, CAN `�itl,S S Pp-- b I DEPT_: .' ` . .-i AUG I u LUIb Zg�s. T y I !!!• DATE: e a� VACANT LOT SE79ACK UNE O I STOOP 1 v' I r S� o it CHANHAWPLANNING PP , C) DEPT.: 50 WALKOUT e: Y I ` 999• •y y LOWEST FLOOR= 993.42 'b �8 `� ,J` a T T z EO PDiIiiSSND� ,� 1 hereby certify that this survey w05 prepared by me or under my direct. supervision and that ��'� a�ao JQ 4' - `l - °- o- I ---•--' I am a duly Licensed Land Surveyor under the —"® 99 a 10004v. 30°�, ''� +� lows ofState of Minnesota. Oo i - 998� \ •.O _ � 980.59 ! J ! l • m 3'. - Craig arse, R.L.S. L50te 6BW °i \'� W. j License No. 23021 9 ----------- nurr U •t" 9 1 U Y o s93 /000? \v \) / / o \ \ X �9900�00 Denotes Denotes existing elevationosed /elevation Ih $1 4 d v ry T Denotes surface drainage �r0-1 / \ \ xxxx Denotes proposed sewer invert p w " I I T? 2.00 "+ I of / I n . REQUESTED BY. MAY 22.0°�o Mauro AUSEN I V i �1r1 1v 9 S� IDEProfessl.ml5eni Ic CITY OF CHANHASSEN 7699Anagmm Drive n, �:1 S A: I yen Prsieie, nil ss344 / �. •� ��+ i :'}Y: PHONE 99293 FAX 95' SET 1 r ? Qi Tai�E �3o / . T o ` :D. t E: `�/ , '�`(f'Y www.en�rvNodcxmm c•�z3idE =.ZiNG ucP . 0 e x, 4f f V• r ,O O 997.56 �- I�0^•'E` EXISTING HOUSE FFE GA2AGE 1000.08 Scai 1"= 20 feet Drawn by. Dote: Job No., F BTW 09/09/08 20082506 200825069802L02.dwg- i 0 2 o 1 I a IE o �z ®a� �j 996 N O `2 2 z D i i M y , -O iii \ C \ N O O CD C ` � \1 r- 0 1 IC. Lot 2, l3ESORI2, LA #ELEVATIONS PROVIDED BY CLIENT# ASHUILT 5"URVEY 9yo2ft''We Lot 2, Block 2, LAKE HARRISON, according to. the Elevations nrovided.bv client recorded plot thereo`, Carver County, Minnesoa. *BUILDING DIMENSIONS DO NOT REFLECT BRICK FACING* Garage Floor = 999.43 at overhead door) *BUILDING DIMENSIONS SHOWN REFLECT LOWER LEVEL PLAN= 6845 Lake Harrison Circle � � � 9 ( BuildingPermit Number 2008-003-04 Top of Foundation Wall = 1001.844 EXISTING HOUSE /`� i DATED FEBRUAP,Y 13, 2008 a, I FFE 99679 0 Lowest Floor = 993.42(9 Foot Basemen f) 995.56 s9zo + = i0 / #CURB AND GUTTER APE EXIS77NG# r Y UT/LI T/ES ARE EXISTING* x R, T o o � _ o �* Lot Area = 17,927 sq. ft.zs"'K ` x = °"ry 6V�¢od3'1 �" m " „ u y� ` Building, stoop and pad = 3,521 sq. ft. 1--- — _ — _ _ _ \ er 165.31 x m y'2 978 98 I Driveway and sidewalk = 920 sq. ft. 0 I \7- �' ';^ o, I Impervious area = 4,441 sq. ft. /24.77 % of total Lot area I 8oULOER RETAINING 9g °. NL —' n I WALL -3!r i=x2FL+- 995.8 - _ �1 SI�•1 m -' \ 0 �l e•' i sg j 20° •oo �g9 Y` 4 ,� __i a I 10 ` j - Denotes iron monument found 40.00 p a1i. O Denotes iron monument set APPS®'��D I I LID Bearings based on assumed datum. BY. 68BW 'ao J/+ DEPT.: Pias- ,ate• .,il. DATE: �'F OFCHANHASSEo' 15 W X y 3� �� 2m N ,��1. O °� WE ND R i 5 i`? 11 RECEIVED F? fQ Ill ,1 - r :0 BY: 111, i 'r —r ,— '� —, w W .90. �Q I X �. .t r , , e t ,' i, CAN `�itl,S S Pp-- b I DEPT_: .' ` . .-i AUG I u LUIb Zg�s. T y I !!!• DATE: e a� VACANT LOT SE79ACK UNE O I STOOP 1 v' I r S� o it CHANHAWPLANNING PP , C) DEPT.: 50 WALKOUT e: Y I ` 999• •y y LOWEST FLOOR= 993.42 'b �8 `� ,J` a T T z EO PDiIiiSSND� ,� 1 hereby certify that this survey w05 prepared by me or under my direct. supervision and that ��'� a�ao JQ 4' - `l - °- o- I ---•--' I am a duly Licensed Land Surveyor under the —"® 99 a 10004v. 30°�, ''� +� lows ofState of Minnesota. Oo i - 998� \ •.O _ � 980.59 ! J ! l • m 3'. - Craig arse, R.L.S. L50te 6BW °i \'� W. j License No. 23021 9 ----------- nurr U •t" 9 1 U Y o s93 /000? \v \) / / o \ \ X �9900�00 Denotes Denotes existing elevationosed /elevation Ih $1 4 d v ry T Denotes surface drainage �r0-1 / \ \ xxxx Denotes proposed sewer invert p w " I I T? 2.00 "+ I of / I n . REQUESTED BY. MAY 22.0°�o Mauro AUSEN I V i �1r1 1v 9 S� IDEProfessl.ml5eni Ic CITY OF CHANHASSEN 7699Anagmm Drive n, �:1 S A: I yen Prsieie, nil ss344 / �. •� ��+ i :'}Y: PHONE 99293 FAX 95' SET 1 r ? Qi Tai�E �3o / . T o ` :D. t E: `�/ , '�`(f'Y www.en�rvNodcxmm c•�z3idE =.ZiNG ucP . 0 e x, 4f f V• r ,O O 997.56 �- I�0^•'E` EXISTING HOUSE FFE GA2AGE 1000.08 Scai 1"= 20 feet Drawn by. Dote: Job No., F BTW 09/09/08 20082506 200825069802L02.dwg- MEMORANDUM TO: MacKenzie Walters, Assistant Planner FROM: Terry Jeffery, Water Resources Coordinator DATE: September 7, 2016 RE: Planning Case 2106-22: Request for variance from hard cover requirements PROJECT UNDERSTANDING The applicant is requesting to exceed allowed hardcover area for a single family residential lot by 8% or 1,459 square feet. The applicant is proposing to mitigate additional stormwater runoff through the use of a pervious paver patio system and a rain garden. SHORELAND MANAGEMENT The property is located within the shoreland management district for Lake Harrison. State rules requires that hardcover on any lot within the shoreland district have no more than 25% impervious surface coverage. There is an abundance of studies showing a correlation between shoreland development and water quality degradation. The Center for Watershed Protection summarized 225 such studies in March of 2003. Research consistently shows that there is negative impacts to water quality when impervious surface coverage exceeds 10%-12%. This review concluded that surface water "managers should be very extremely cautious in setting high expectations for how much watershed treatment can mitigate impervious cover..." Still other studies showed that areas were surface reservoirs are used for drinking water, the reservoirs cannot sustain safe drinking water supplies when impervious surface exceeds 25%. Minnesota Statutes, 103F, Sections 201-227 and the statewide Shoreland Management Program were drafted with these facets of watershed science in mind. Pervious pavement has been shown to be a very effective stormwater management tool. With proper design, installation and maintenance these practices promote infiltration rates that can approach hundreds of inches per hour thereby reducing runoff and pollutant loading. Pervious paver systems will degrade over time as the surface becomes clogged but according to the Environmental Protection Agency, will still have an infiltration rate in excess of 1" per hour. Care must be taken during maintenance to avoid the use of sand for winter maintenance and to vacuum and/or power wash the surface at regular intervals. In some pervious paver systems the rock within the joints will need replacement. It is also true that lawns, compacted during construction, can behave as impervious surfaces. However, the MN Department of Natural Resources has issued guidance for the use of permeable pavement systems in shoreland areas. Within this guidance the caution; "If taken as part of the overall site design and used as part of a larger stormwater management plan, permeable pavement systems can compensate for some of the impacts that other impervious surfaces have on a lot. However, they do not take the place of native vegetation and undisturbed soils, especially, in the Shore Impact Zone, that area which is closest to the shore and extends to half the setback of the structures."— Permeable Pavement Systems in Shoreland Areas, A Guide to Local Governmental Units, DNR Waters, St. Paul, MN, September 30, 2003. The DNR's final recommendation was that pervious pavement systems be used on new development where impervious coverage could be kept to 10% and the pervious pavement system makes up the next 15% of hardcover to get to that 25%. They do not recognize it as a practice to allow for exceedance of hard cover limitations. Chanhassen has adopted several policies and practices already intended to help homeowners with the matter of hardcover. We do not count retaining walls against hard cover, we do not count swimming pools against hardcover and we do not count wetlands or other water features against the hardcover calculations although all of these surfaces produce more runoff than natural vegetation or even lawn. Chanhassen uses hardcover and impervious surface interchangeably. This can be misleading as the allowance of permeable pavement systems is not solely a function of storm water management. In addition to it being a stormwater issue, there is the question of green space. How much is enough? It is conceivable that one could make the entire property pervious through the use of a pervious pavement system. However, the site would still have 100% hardcover. WETLAND PROTECTION When Lake Harrison was developed, there were several wetland impacts. Much of the mitigation for these impacts was completed on-site. Mitigation areas M6 and M7 are located behind Lots 1-4 of Block 2. As part of this mitigation, a 20 foot buffer was created. This buffer was not only required by code but is part of the mitigation for the impacts. At the time of the development, the setback was 40 feet from the buffer regardless of if the structure was considered primary or secondary. Under these rules, the entire pool and LOT 2 1. Lake Harrison Wetland Mitigation Plan the majority of the patio are within the setback area and are not allowed. Section 20-411 of current code allows for the adoption of existing buffer standards. This would require the creation of a 25 foot permanent buffer strip vegetated with all native species. The monuments would need to be placed at the buffer and the new buffer and setbacks would need to be recorded. The setbacks would then be 30 feet for the primary structure and 15 feet for any secondary structures such as a pool and patio. Under this scenario, the wall could not be within the buffer and the pool and patio would need to be at least 40 feet total from the wetland boundary. Even if this method was selected, the majority of the pool and a significant portion of the patio are still within the setback and would not be an allowed use. Even with the revised buffers, the applicant will still need to comply with the requirements of other agencies with legal jurisdiction in Chanhassen. Riley Purgatory Bluff Creek Watershed District has buffer rules which are, in many cases stricter than Chanhassen's. The applicant will need to meet their buffer requirements as well. Figure 2. Buffer and Setback Based Upon Plat. No structures could be placed outside of green setback line. Figure 3. Buffer and Setback if Changed to Today's Rules Given the guidance provided by the DNR, the condition of Riley Creek, the anti -degradation requirements of the City's NPDES Municipal Separate Storm Sewer Permit, and the question of aesthetics, I recommend denial of the variance request. In the event this recommendation is not followed, the following conditions should be applied to any approval. 1. Site specific infiltration data, at the proposed surface elevation must be provided. 2. The applicant must demonstrate that there will be a minimum separation to groundwater of three (3) feet or more. 3. Hydrologic and hydraulic calculations must be provided and demonstrate that the permeable paver system and rain garden not only mitigates for the proposed increase, but can accommodate tributary drainage areas directed to them for the design storm. ru a Ar.� 'm� ,._vn. - y • r may, Figure 3. Buffer and Setback if Changed to Today's Rules Given the guidance provided by the DNR, the condition of Riley Creek, the anti -degradation requirements of the City's NPDES Municipal Separate Storm Sewer Permit, and the question of aesthetics, I recommend denial of the variance request. In the event this recommendation is not followed, the following conditions should be applied to any approval. 1. Site specific infiltration data, at the proposed surface elevation must be provided. 2. The applicant must demonstrate that there will be a minimum separation to groundwater of three (3) feet or more. 3. Hydrologic and hydraulic calculations must be provided and demonstrate that the permeable paver system and rain garden not only mitigates for the proposed increase, but can accommodate tributary drainage areas directed to them for the design storm. 4. The design of the permeable pavement system shall follow MN Stormwater Manual guidelines unless manufacturer specifications expressly recommend against those guidelines. This includes the typical cross-section. 5. Construction practices to be employed to avoid compaction of the subsurface including ripping the in situ soils to a minimum depth of 12 inches. 6. The design of the rain garden shall follow MN Stormwater Manual guidelines. 7. A maintenance and operations manual describing anticipated inspections, annual maintenance, responsible parties and annual reporting forms. 8. A detailed erosion prevention and sediment control plan shall be submitted to the city for review and approval. 9. The applicant must apply for and obtain permissions from Riley Purgatory Bluff Creek Watershed District and any other agency with legal jurisdiction over the site. 10. The site must comply with today's buffer standards. A buffer, minimum 25 feet in width must be established with 100% native vegetation, demarcated with signage, and recorded with the property. 11. All structures must be located outside of the secondary setback assuming buffers updated to current wetland protection requirements. resourceful. naturally. BARR engineering and environmental consultants Memorandum To: MacKenzie Walters, Assistant Planner; City of Chanhassen From: Scott Sobiech, PE Subject: 6845 Lake Harrison Circle Plan Review by Riley -Purgatory -Bluff Creek Watershed District Date: September 7, 2016 c: Claire Bleser; Administrator Riley -Purgatory -Bluff Creek Watershed District We appreciate the opportunity to provide preliminary comments on the proposed construction of a pool and paver patio at an existing single family home at 6845 Lake Harrison Circle. The Riley -Purgatory -Bluff Creek Watershed District (RPBCWD) received a request for preliminary review of this project on August 31, 2016. This is a preliminary review of the submitted information; additional comments may need to be addressed prior to issuance of a permit based on further review of the plans or revised information that is submitted. This proposed development will need a RPBCWD permit prior to beginning land disturbing activities. The following comments are based on the rules that appear to apply to this project and highlight the areas where revisions or additional information are needed to meet the RPBCWD rules. These review comments do not constitute approval, a variance, or exemption from the rules. Therefore this project will require permit approvals from the RPBCWD Board of Managers. Rule C: Erosion and Sediment Control Conformance with the Erosion and Sediment Control Rule (Rule C) is required from the RPBCWD because more than 50 cubic yards of earth will be placed, altered, or removed (Rule C, Section 2.1). The following comments must be addressed for the project to be in compliance with RPBCWD Rule C. • An erosion control plan for the site must be provided. • The erosion control plan must include the following notes: o Soil surfaces compacted during construction and remaining pervious upon completion of construction must be decompacted through soil amendment and/or ripping to a depth of 8 inches while taking care to avoid utilities, tree roots and other existing vegetation prior to final revegetation or other stabilization. o Construction site waste such as discarded building materials, concrete truck washout, chemicals, litter and sanitary waste must be properly managed. o Natural topography and soil conditions must be protected, including retention onsite of native topsoil to the greatest extent possible. Barr Engineering Co. 4700 West 77th Street, Suite 200, Minneapolis, MN 55435 952,832.2600 www.barrcom To: MacKenzie Walters, Assistant Planner; City of Chanhassen From: Scott Sobiech, PE Subject: 6845 Lake Harrison Circle Plan Review by Riley -Purgatory -Bluff Creek Watershed District Date: September 7, 2016 o Additional measures, such as hydraulic mulching and other practices as specified by the District must be used on slopes of 3:1(H:V) or steeper to provide adequate stabilization. o Final site stabilization measures must specify that at least six inches of topsoil or organic matter be spread and incorporated into the underlying soil during final site treatment wherever topsoil has been removed. o All temporary erosion and sediment control BMPs must be maintained until completion of construction and vegetation is established sufficiently to ensure stability of the site, as determined by the District. o All temporary erosion and sediment control BMPs must be removed upon final stabilization. o All disturbed areas must be stabilized within 7 calendar days after land -disturbing work has temporarily or permanently ceased on a property that drains to an impaired water, within 14 days elsewhere. o The permittee must, at a minimum, inspect, maintain and repair all disturbed surfaces and all erosion and sediment control facilities and soil stabilization measures every day work is performed on the site and at least weekly until land -disturbing activity has ceased. Thereafter, the permittee must perform these responsibilities at least weekly until vegetative cover is established. The permittee will maintain a log of activities under this section for inspection by the District on request. Rule D: Wetland and Creek Buffers A wetland on this parcel appears to be downgradient from the proposed site activities. Because the proposed work triggers RPBCWD's Stormwater Management Rule (Rule J) and there is a wetland downgradient of the activities, Rule D, Subsections 2.1a and 3.1 require buffer around this wetland. To conform to the RPBCWD Rule D the following revisions are needed: Because a wetland appears to be downgradient, a wetland delineation by a certified wetland delineator is needed for the wetlands downgradient of the proposed construction to determine the buffer location. Because the project is located on an existing single family home parcel, a buffer with a 20 foot average, 10 foot minimum width must be provided. A wetland buffer area must be shown on the plans and indicated by permanent, free- standing markers at the buffer's upland edge. Please provide an example detail for the marker locations noted on the plans. An example detail is available for download from the RPBCWD website (www.rpbcwd.org/permits). To: MacKenzie Walters, Assistant Planner; City of Chanhassen From: Scott Sobiech, PE Subject: 6845 Lake Harrison Circle Plan Review by Riley -Purgatory -Bluff Creek Watershed District Date: September 7, 2016 Page: 3 o A note must be added to the plans indicating: The potential transfer of aquatic invasive species (e.g., zebra mussels, Eurasian watermilfoil, etc) must be minimized to the maximum extent possible. o Before any work subject to District permit requirements commences, buffer areas and maintenance requirements must be documented. The applicant may meet this requirement by entering into a maintenance declaration recorded with the County. Rule J: Stormwater Management Conformance with the RPBCWD Stormwater Management rule (Rule J) will be required for this project because more than 50 cubic yards of earth will be placed, altered, or removed or more than 5,000 square feet of land -surface area will be altered (Rule 1, Section 2.1) and the parcel is within 500 feet of and draining to a wetland. Comments provided below are preliminary and general in nature and the applicant should review the RPBCWD's Stormwater Management Rule for full details on submittal requirements. General Comments: o In accordance with RPBCWD Rule J, Subsection 3.4 the project must provide for the construction, installation, or implementation of a stormwater-management BMP. The rain garden shown on the plan could likely be considered as a stormwater-management BMP. Wetland buffer is allowed to be credited to the stormwater requirement per Rule J, Subsection 3.5. The construction, installation or implementation of a stormwater- management BMP must be consistent with guidance promulgated by the State of Minnesota, including but not limited to the Minnesota Stormwater Manual, Protecting Water Quality in Urban Areas Manual and Minimal Impact Design standards. o The lowest floor elevation of the home must be at least 2 feet above the flood elevation of the stormwater-management BMP. o Permit applicant must provide a draft maintenance declaration and inspection plan for review and approval by the RPBCWD. Once approved the declaration must be recorded with the County. A maintenance declaration template is available on the permits page of the RPBCWD website. (http://www.rpbcwd.org/permits/). Summary Based on the information provided to date, the proposed design does not meet the RPBCWD rules and a permit from the RPBCWD will be required prior to construction to likely cover the following: Erosion and Sediment Control, Wetland and Creek Buffers, and Stormwater Management. The permit application and detailed information on the RPBCWD rules are available for download on the RPBCWD website: httr)-//www.rr)bcwd.org/r)ermits Please contact us with any questions. CITY OF CHANHASSEN AFFIDAVIT OF MAILING NOTICE STATE OF MINNESOTA) ) ss. COUNTY OF CARVER ) I, Kim T. Meuwissen, being first duly sworn, on oath deposes that she is and was on September 8, 2016, the duly qualified and acting Deputy Clerk of the City of Chanhassen, Minnesota; that on said date she caused to be mailed a copy of the attached notice of a hearing to consider a variance to build a paver patio around a pool at property located at 6845 Lake Harrison Circle to the persons named on attached Exhibit "A", by enclosing a copy of said notice in an envelope addressed to such owner, and depositing the envelopes addressed to all such owners in the United States mail with postage fully prepaid thereon; that the names and addresses of such owners were those appearing as such by the records of the County Treasurer, Carver County, Minnesota, and by other appropriate records. 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VI Q o7i w z 1++ fY U Z CQS JiQ,W W W m O Z 4 Q K m Q x w Q x Y Y Qviz Z x Z Y J IRS J VI S J S J W J Vl O W� im d= W @ Z Q Z} U= Q, 2 x= w Z K W K alva,sdF-0Q�u_QU_0 m u_zu� m IJ W Q,- Q J 0Zz>Uoz0LL5 O G LL z H N m N J W G Q C 0 a Q O N 1' U Z 0 U N G LL C7 1� CI 1' W N r -wi 11 MEMORANDUM CITYOF TO: MacKenzie Walters, Assistant Planner FROM: Terry Jeffery, Water Resources Coordinator 7700 Market Boulevard DATE: October 4, 2016 PO Box 147 Chanhassen, MN 55317 RE: Planning Case 2106-22: Request for variance from hard cover requirements Administration Phone: 952.227.1100 PROTECT UNDERSTANDING Fax:952.227.1110 Building Inspections The applicant is requesting to exceed allowed hardcover area for a single family residential Phone: 952.227.1180 lot by 8% or 1,459 square feet. The applicant is proposing to mitigate additional stormwater Fax: 952.227.1190 runoff through the use of a pervious paver patio system and a rain garden. The applicant has submitted a revised alternate design that uses current buffer standards (see section entitled Engineering WETLAND PROTECTION) and meets those setbacks. It appears that the exceedance is Phone: 952.227.1160 reduced by 659 square feet to 800 square feet under this alternative. Fax: 952.227.1170 Planning & SHORELAND MANAGEMENT Finance reservoirs cannot sustain safe drinking water supplies when impervious surface exceeds 25%. Phone: 952.227.1140 Minnesota Statutes, 103F, Sections 201-227 and the statewide Shoreland Management Fax 952.227.1110 The property is located within the shoreland management district for Lake Harrison. State Public Works rules requires that hardcover on any lot within the shoreland district have no more than 25% Park & Recreation impervious surface coverage. There is an abundance of studies showing a correlation Phone: 952.227.1120 between shoreland development and water quality degradation. The Center for Watershed Fax: 952.227.1110 Protection summarized 225 such studies in March of 2003. Research consistently shows that there is negative impacts to water quality when impervious surface coverage exceeds 10% - Recreation Center 12%. This review concluded that surface water "managers should be very extremely cautious 2310 Coulter Boulevard Phone: 952.227.1400 in setting high expectations for how much watershed treatment can mitigate impervious Fax: 952.227.1404 cover..." Planning & Still other studies showed that areas were surface reservoirs are used for drinking water, the Natural Resources reservoirs cannot sustain safe drinking water supplies when impervious surface exceeds 25%. Phone: 952.227.1130 Fax 952.227.1110 Minnesota Statutes, 103F, Sections 201-227 and the statewide Shoreland Management Program were drafted with these facets of watershed science in mind. Public Works 7901 Park Place Pervious pavement has been shown to be a very effective stormwater management tool. With Phone: 952.227.1300 proper design, installation and maintenance these practices promote infiltration rates that can Fax: 952.227.1310 approach hundreds of inches per hour thereby reducing runoff and pollutant loading. Pervious paver systems will degrade over time as the surface becomes clogged but according Senior Center to the Environmental Protection Agency, will still have Phone: 952.227.1125 Fax: 952.227.1110 Website www.ci. chanhassen. m n.us Chanhassen is a Community for Life -Providing for Today and Planning for Tomorrow Planning Case #2016-22 Water Resources Memo October 4, 2016 Page 2 of 4 an infiltration rate in excess of 1" per hour. Care must be taken during maintenance to avoid the use of sand for winter maintenance and to vacuum and/or power wash the surface at regular intervals. In some pervious paver systems the rock within the joints will need replacement. This rock should never be derived from limestone as that breaks down and can result in clogging of the system. It is also true that lawns, compacted during construction, can behave as impervious surfaces. However, the MN Department of Natural Resources has issued guidance for the use of permeable pavement systems in shoreland areas. Within this guidance the caution; "If taken as part of the overall site design and used as part of a larger stormwater management plan, permeable pavement systems can compensate for some of the impacts that other impervious surfaces have on a lot. However, they do not take the place of native vegetation and undisturbed soils, especially, in the Shore Impact Zone, that area which is closest to the shore and extends to half the setback of the structures. "— Permeable Pavement Systems in Shorcland Areas, A Guide to Local Governmental Units, DNR Waters, St. Paul, MN, September 10, 2003. The DNR's final recommendation was that pervious pavement systems be used on new development where impervious coverage could be kept to 10% and the pervious pavement system makes up the next 15% of hardcover to get to that 25%. They do not recognize it as a practice to allow for exceedance of hard cover limitations. Chanhassen has adopted several policies and practices already intended to help homeowners with the matter of hardcover. We do not count retaining walls against hard cover, we do not count swimming pools against hardcover and we do not count wetlands or other water features against the hardcover calculations although all of these surfaces produce more runoff than natural vegetation or even lawn. Chanhassen uses hardcover and impervious surface interchangeably. This can be misleading as the allowance of permeable pavement systems is not solely a function of storm water management. In addition to it being a stormwater issue, there is the question of green space. How much is enough? It is conceivable that one could make the entire property pervious through the use of a pervious pavement system. However, the site would still have 100% hardcover. WETLAND PROTECTION When Lake Harrison was developed, there were several wetland impacts. Much of the mitigation for these impacts was completed on-site. Mitigation areas M6 and M7 are located behind Lots 1 — 4 of Block 2. As part of this mitigation, a 20 foot buffer was created. This buffer was not only required by code but is part of the mitigation for the impacts. At the time of the development, the setback was 40 feet from the buffer regardless of if the structure was considered primary or secondary. Under these rules, the entire pool and the majority of the patio are within the setback area and are not allowed. Planning Case #2016-22 Water Resources Memo October 4, 2016 Page 3 of 4 Section 20-411 of current code allows for the adoption of existing buffer standards. This would require the creation of a 25 foot permanent buffer strip vegetated with all native species. The monuments would need to be placed at the buffer and the new buffer and setbacks would need to be recorded. The setbacks would then be 30 feet for the primary structure and 15 feet for any secondary structures such as a pool and patio. Under this scenario, the wall could not be within the buffer and the pool and patio would need to be at least 40 feet total from the wetland boundary. Even if this method was selected, under the original proposal, the majority of the pool and a significant portion of the patio are still within the setback and would not be an allowed use. In t Fiaure 1. Lake Harrison Wetland Mitigation Plan Even with the revised buffers, the applicant will still need to comply with the requirements of other agencies with legal jurisdiction in Chanhassen. Riley Purgatory Bluff Creek Watershed District has buffer rules which are, in many cases stricter than Chanhassen's. The applicant will need to meet their buffer requirements as well. Figure 2. Buffer and Setback Based Upon Plat. No -- -- - — structures could be placed outside ofgreen setback tine. Figure 3. Buffer and Setback t(Changed to Today's Rules Given the guidance provided by the DNR, the condition of Riley Creek, the anti -degradation requirements of the City's NPDES Municipal Separate Storm Sewer Permit, and the question of aesthetics, I recommend denial of the variance request. In the event this recommendation is not followed, the following conditions should be applied to any approval. _. ------ -- i R i LOT 2 d ;3 `a I Fiaure 1. Lake Harrison Wetland Mitigation Plan Even with the revised buffers, the applicant will still need to comply with the requirements of other agencies with legal jurisdiction in Chanhassen. Riley Purgatory Bluff Creek Watershed District has buffer rules which are, in many cases stricter than Chanhassen's. The applicant will need to meet their buffer requirements as well. Figure 2. Buffer and Setback Based Upon Plat. No -- -- - — structures could be placed outside ofgreen setback tine. Figure 3. Buffer and Setback t(Changed to Today's Rules Given the guidance provided by the DNR, the condition of Riley Creek, the anti -degradation requirements of the City's NPDES Municipal Separate Storm Sewer Permit, and the question of aesthetics, I recommend denial of the variance request. In the event this recommendation is not followed, the following conditions should be applied to any approval. Planning Case #2016-22 Water Resources Memo October 4, 2016 Page 4 of 4 1. Site specific infiltration data, at the proposed infiltration surface elevation must be provided. 2. The applicant must demonstrate that there will be a minimum separation to ground water of three (3) feet or more where the pervious pavement will be employed. 3. Hydrologic and hydraulic calculations must be provided and demonstrate that the permeable paver system and rain garden not only mitigates for the proposed increase, but can accommodate tributary drainage areas directed to them for the design storm. 4. The design of the permeable pavement system shall follow MN Stormwater Manual guidelines unless manufacturer specifications expressly recommend against those guidelines. This includes the typical cross-section. 5. Construction practices to be employed to avoid compaction of the subsurface including ripping the in situ soils to a minimum depth of 12 inches. 6. The design of the rain garden shall follow MN Stormwater Manual guidelines. 7. A maintenance and operations manual describing anticipated inspections, annual maintenance, responsible parties and annual reporting forms. 8. A detailed erosion prevention and sediment control plan shall be submitted to the city for review and approval. 9. The applicant must apply for and obtain permissions from Riley Purgatory Bluff Creek Watershed District and any other agency with legal jurisdiction over the site. 10. The site must comply with today's buffer standards. A buffer, minimum 25 feet in width must be established with 100% native vegetation, clearly indicated on the plan set, demarcated with signage, and recorded with the property. 11. All structures must be located outside of the secondary setback assuming buffers updated to current wetland protection requirements. From: Mark Hauri [mailto:mhauri@outdoorexcaoes.com] Sent: Monday, October 3, 2016 5:55 PM To: Walters, MacKenzie <MWalters@ci.chanhassen.mn.us> Subject: Hegenes Revision McKenzie, I've been frantically working away on this. Here is what we are proposing for our Appeal meeting. Our Major Revisions Are: 1. We will take advantage of the ordinance to create a 25' Wetland Setback and then only a 15' additional setback which the pool will now clear. 2. 800 ft2 of Permeable pavers and the bar area for a total of 29.2% hardcover I'm still working on detailing up the complete project, but this is what we want to do. Sincerely, Mark Hauri Landscape Designer Outdoor Excapes Cell 1 651.503.6585 Email mhauri@outdoorexcaaes.com Web www.outdoorexcapes.com Outdoor Excapes 1 2345 Daniels Street I Long Lake, MN 55356 Lp iio NwO>Iew6*OenaH€9S NN'N3SS HNVHJNOSIbHVH 3Atl SA9 193fONd 53N393H 8aV8 a � E N � Q d K 1� d i I�E 9� Cl'rYQFCHANHA88B RECEIVED SEI' 2 3 2016 GI IA$IENINAN"DEpi Date: September 23, 2016 Mark Hauri Landscape Design with Outdoor Excapes Acting on behalf of Barb Hegenes at property address: 6845 Lake Harrison Circle Chanhassen, MN 55317 PID 254170140 RE: LETTER TO APPEAL DENIAL OF VARIANCE IN CASE #2016-22 I am acting on behalf of my client Barb Hegenes to request and appeal of the denial of our variance request, Case #2016-22, by the City Planning Commission on Tuesday, September 20, 2016. We would like have our appeal heard at the City Council meeting on October 10, 2016. Sincerely, Mark A Hauri Landscape Designer Outdoor Excapes mhauri@outdoorexcapes.com 651-503-6585 CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA FINDINGS OF FACT AND DECISION (DENIAL) IN RE: Barb Hegenes appeal of Chanhassen Planning Commission's denial of a variance to allow hardcover to exceed 25 percent by 8.14 percent, allow a detached accessory structure to exceed the rear lot coverage limit of 30 percent by 4.5 percent, and allow a 15 -foot reduction in the wetland buffer setback on property zoned Single -Family Residential District (RSF)-Planning Case 2016-22. On October 4, 2016 staff received revised proposal from Barb Hegenes requesting a hardcover variance of 4.2 percent. On October 10, 2016, the Chanhassen City Council met at its regularly scheduled meeting to consider the appeal. The City Council makes the following: FINDINGS OF FACT 1. The property is currently zoned Single -Family Residential District (RSF). 2. The property is guided in the Chanhassen Comprehensive Plan for Residential Low Density. 3. The legal description of the property is: Lot 2, Block 2, Lake Harrison 4. Variance Findings —Section 20-58 of the City Code provides the following criteria for the granting of a variance: a. Variances shall only be permitted when they are in harmony with the general purposes and intent of this Chapter and when the variances are consistent with the comprehensive plan. Finding: The subject site is zoned Single -Family Residential District. The purpose of the request is to provide an area for family recreation in the rear yard. While this type of use is in harmony with the intent of the RSF District, permitting a pool area of this size is not in harmony with the intent of the district's coverage requirements, both as they pertain to stormwater management and the aesthetics of the neighborhood. No other property in the neighborhood has been allowed to exceed the RSF District's hard cover limit. The property currently has decks which allow for the use and enjoyment of the rear yard, and does not require the proposed pool area to allow the utilization of the rear yard. The property is also located within Lake Harrison's shoreland management district. Permitting properties within the shoreland management district to have impervious surface in excess of 25 percent is not in harmony with shoreland management district's goal of protecting and preserving water quality. b. When there are practical difficulties in complying with the zoning ordinance. "Practical difficulties," as used in connection with the granting of a variance, means that the property owner proposes to use the property in a reasonable manner not permitted by this Chapter. Practical difficulties include, but are not limited to, inadequate access to direct sunlight for solar energy systems. Finding: The property currently complies with the City Code. The owner has options within the code for creating a rear yard family area including expanding the existing decks, constructing a detached deck in the rear yard, building a pergola, and other similar structures that would not increase the lot's hardcover. Historically, a permit to build a pool was issued for this property without any variance being requested or granted. Requesting an additional 759.25 sq. ft. of impervious surface to construct a pool area is not a practical difficulty in meeting the City Code. c. That the purpose of the variation is not based upon economic considerations alone. Finding: The stated intent is to create a family oriented pool area in the rear yard. Although the proposed pool area would increase the property's value, the request does not appear to be based upon economic considerations. d. The plight of the landowner is due to circumstances unique to the property not created by the landowner. Finding: When the house was built all of the existing regulations regarding impervious surfaces and lot coverage were in place. The lot is larger than the minimum lot size required in the RSF district. The inability to increase the amount of impervious surface is due to the fact that the house and driveway were designed and built to cover 24.77 percent of the lot, not due to any unique feature of the lot. The inability to construct the proposed accessory structure is the result of its proposed design. e. The variance, if granted, will not alter the essential character of the locality. Finding: The house immediately north has a pool and many other properties in the neighborhood have recreational areas in their rear yards. Due to the location of the proposed pool area, house placement, and proposed screening the project's impact on the neighborhoods will be minimal. f. Variances shall be granted for earth sheltered construction as defined in Minnesota Statutes Section 216C.06, subdivision 14, when in harmony with this Chapter. Finding: This does not apply to this request. 5. The planning report #2016-22, dated September 20, 2016, prepared by MacKenzie Walters, is incorporated herein. DECISION "The Chanhassen City Council denies the variance request to allow a 4.2 percent hardcover variance." ADOPTED by the City Council this 10' day of October, 2016. CITY OF CHANHASSEN m Chairman CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA FINDINGS OF FACT AND DECISION (APPROVAL) IN RE: Barb Hegenes appeal of Chanhassen Planning Commission's denial of a variance to allow hardcover to exceed 25 percent by 8.14 percent, allow a detached accessory structure to exceed the rear lot coverage limit of 30 percent by 4.5 percent, and allow a 15 -foot reduction in the wetland buffer setback on property zoned Single -Family Residential District (RSF)-Planning Case 2016-22. On October 4, 2016 staff received revised proposal from Barb Hegenes requesting a hardcover variance of 4.2 percent. On October 10, 2016, the Chanhassen City Council met at its regularly scheduled meeting to consider the appeal. The City Council makes the following: FINDINGS OF FACT 1. The property is currently zoned Single -Family Residential District (RSF). 2. The property is guided in the Chanhassen Comprehensive Plan for Residential Low Density. 3. The legal description of the property is: Lot 2, Block 2, Lake Harrison 4. Variance Findings —Section 20-58 of the City Code provides the following criteria for the granting of a variance: a. Variances shall only be permitted when they are in harmony with the general purposes and intent of this Chapter and when the variances are consistent with the comprehensive plan. Finding: The subject site is zoned Single -Family Residential District. The purpose of the request is to provide an area for family recreation in the rear yard. This use is in harmony with the intent of the RSF District. The proposed paver patio system will mitigate the runoff generated by the properties increased hardcover. By allowing for improved infiltration this system will reduce the property's stormwater to a level that is in harmony with the intent of the 25 percent lot coverage limit. b. When there are practical difficulties in complying with the zoning ordinance. "Practical difficulties," as used in connection with the granting of a variance, means that the property owner proposes to use the property in a reasonable manner not permitted by this Chapter. Practical difficulties include, but are not limited to, inadequate access to direct sunlight for solar energy systems. Finding: Given the existing house configuration the applicant could not install a reasonable pool area without exceeding the zoning code's hardcover restrictions. c. That the purpose of the variation is not based upon economic considerations alone. Finding: The stated intent is to create a family oriented pool area in the rear yard. Although the proposed pool area would increase the property's value, the request does not appear to be based upon economic considerations. d. The plight of the landowner is due to circumstances unique to the property not created by the landowner. Finding: Market trends at the time of the house's construction favored large houses with three car garages. Given the dimensions of the lot and location of the rear wetland the property simply does not have enough acreage to allow for a reasonable pool area while maintaining less than 25 percent lot coverage. e. The variance, if granted, will not alter the essential character of the locality. Finding: The house immediately north has a pool and many other properties in the neighborhood have recreational areas in their rear yards. Due to the location of the proposed pool area, house placement, and proposed screening the project's impact on the neighborhoods will be minimal. f. Variances shall be granted for earth sheltered construction as defined in Minnesota Statutes Section 216C.06, subdivision 14, when in harmony with this Chapter. Finding: This does not apply to this request. 5. The planning report #2016-22, dated September 20, 2016, prepared by MacKenzie Walters, is incorporated herein. 2 DECISION "The Chanhassen City Council approves the variance request to allow a 4.2 percent hardcover variance. The approved hardcover variance is subject to the following conditions:" 1. The property's hardcover is not to exceed 29.2 percent. 2. Site specific infiltration data, at the proposed infiltration surface elevation must be provided. 3. The applicant must demonstrate that there will be a minimum separation to ground water of three (3) feet or more where the pervious pavement will be employed. 4. Hydrologic and hydraulic calculations must be provided and demonstrate that the permeable paver system and rain garden not only mitigates for the proposed increase, but can accommodate tributary drainage areas directed to them for the design storm. 5. The design of the permeable pavement system shall follow MN Stormwater Manual guidelines unless manufacturer specifications expressly recommend against those guidelines. This includes the typical cross-section. 6. Construction practices to be employed to avoid compaction of the subsurface including ripping the in situ soils to a minimum depth of 12 inches. 7. The design of the rain garden shall follow MN Stormwater Manual guidelines. 8. A maintenance and operations manual describing anticipated inspections, annual maintenance, responsible parties and annual reporting forms must be provided. 9. A detailed erosion prevention and sediment control plan shall be submitted to the city for review and approval. 10. The applicant must apply for and obtain permissions from Riley Purgatory Bluff Creek Watershed District and any other agency with legal jurisdiction over the site. 11. The site must comply with today's buffer standards. A buffer, minimum 25 feet in width must be established with 100 percent native vegetation, clearly indicated on the plan set, demarcated with signage, and recorded with the property. 12. All structures must be located outside of the secondary setback assuming buffers updated to current wetland protection requirements. 13. The applicant must apply for and receive a building permit from the city. ADOPTED by the Chanhassen City Council this 101 day of October, 2016. CITY OF CHANHASSEN mm Chairman