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E-3a. Camden Ridge, Approve Final PlatCITY OF CHANHASSEN 7700 Market Boulevard PO Box 147 Chanhassen, MN 55317 Administration Phone: 952.227.1100 Fax: 952.227.1110 Building Inspections Phone: 952.227.1180 Fax 952.227.1190 Engineering Phone: 952.227.1160 Fax: 952.227.1170 Finance Phone: 952.227.1140 Fax: 952.227.1110 Park & Recreation Phone: 952.227.1120 Fax: 952.227.1110 Recreation Center 2310 Coulter Boulevard Phone: 952.227.1400 Fax: 952.227.1404 Planning & Natural Resources Phone: 952.227.1130 Fax: 952.227.1110 Public Works 7901 Park Place Phone: 952.227.1300 Fax: 952.227.1310 Senior Center Phone: 952.227.1125 Fax: 952.227.1110 Web Site www.ci.chanhassen.mn.us MEMORANDUM TO: Todd Gerhardt, City Manager FROM: Bob Generous, Senior Planner DATE: September 9, 2013 d F. SUBJ: Final Plat Approval — Camden Ridge Planning Case #2013 -13 PROPOSED MOTION "The Chanhassen City Council approves the final plat for Camden Ridge subject to the conditions of the staff report." Approval requires a majority vote of City Council. PROPOSAL SUMMARY The applicant, Lennar a subdivision of U.S. Home Corporation, is requesting final plat approval for a 32 single - family lots, 26 twinhome lots, and seven outlots on approximately 23 acres zoned Planned Unit Development - Residential (PUD -R) located at 1500 Pioneer Trail and legally described as Outlot A, Jeurissen Ridge. On July 22, 2013, the Chanhassen City Council approved the following: A. Rezoning from Agricultural Estate (A -2) to Planned Unit Development - Residential (PUD -R) for Camden Ridge; B. Preliminary plat of approximately 23 acres into 32 single - family lots, 26 twinhome lots and 7 outlots; C. Conditional Use Permit to allow for development within the Bluff Creek Overlay District for the Camden Ridge development; and D. Development Contract for grading of Camden Ridge. E. The Final Plat for Jeurissen Ridge which created four outlots. Outlot B contains the Bluff Creek primary zone to be preserved in conjunction with Camden Ridge, and Outlot A contains the land for Camden Ridge. Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow SCAM Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 2 SUBDIVISION REVIEW The applicant is requesting final plat approval for 32 single - family lots, 26 twinhome lots, and seven outlots in a residential subdivision. The Bluff Creek primary zone boundary follows the southern perimeter of the site. Access will be via an extension of River Rock Drive South which serves the development to the north, The Preserve at Bluff Creek. STREETS AND ACCESS CAMDEN RIDGE uu- 9 � I ,s E 1 t The developer proposes to construct 31 -foot wide local streets throughout the development. The portion of River Rock Drive South that connects to Bluff Creek Boulevard must be within a 60 -foot wide right of way. The other streets must be within a 55 -foot wide right of way. The right of way is reduced 5 feet in the development to reduce impacts to the Bluff Creek primary zone. Henry Court and Jeurissen Drive are 90 -foot diameter cul -de -sacs within 120 -foot wide right of way. The profile of Henry Court must be revised to ensure the profile meets the minimum length requirements for vertical curves. The proposed centerline grade within 30 feet of an intersection must not exceed 3% According to City Code § 18- 57(k), a street terminating in a cul -de -sac cannot be longer than 800 feet. This site is bordered by TH 212 and Bluff Creek Boulevard, so an additional street connection is impractical. To comply with § 18- 57(k), the Access Path, located in the northwest portion of the development, will act as an emergency access in the future. It will provide access to the north of the development in case of an emergency that could block access to Bluff Creek Boulevard via River Rock Drive. The Access Path is not intended to regularly carry traffic. It is 20 feet wide and is within 30 feet of right of way. The City of Chanhassen shall own and maintain this access. The Access Path shall be shifted as far east as practical to reduce impact to the Bluff Creek primary zone. The development is adjacent to Bluff Creek Boulevard and is therefore subject to the arterial collector fee at the time of final plat. The fee shall be $32,904.00 ($2,400 x 13.71 developable acres). Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 3 The proposed trail begins at the southeast corner of the development in Outlot F and runs along the southern edge of the development, following Bluff Creek. It ties into an existing trail near the existing storm water pond. The trail profile shall be revised to have a minimum slope of 1.0 percent to facilitate drainage on the bituminous pavement. GRADING, DRAINAGE AND EROSION Bluff Creek flows through the property from west to east. The existing drainage on the northwest corner of the development drains into an existing retaining pond before discharging to Bluff Creek. The majority of the property's surface water runoff drains to Bluff Creek. The eastern section of the property drains into the TH 212 ditch system, and the northeast corner of the property drains northeast into a wetland. The proposed drainage would divert storm water to the existing retaining pond and two new ponds before it leaves the site. Pond 1 and Pond 2 would discharge water to Bluff Creek. Erosion Prevention and Sediment Control The applicant has provided a detailed erosion prevention and sediment control plan. This plan covers best management practices that will be used for all phases of the project from demolition and removals to final stabilization. The plan adequately addresses the requirements of Chapter 19 in city code and the required elements under the General Permit Authorization to Discharge Stormwater Associated with Construction Activity MNR100001. A standalone Surface Water Pollution Prevention Plan (SWPPP) was submitted for review. While elements of the SWPPP will need to be updated with the project, the document is extremely well organized and thorough — addressing all obviously foreseeable scenarios. Section 1.2 of the SWPPP "Contact Information/Responsible Parties" needs to be updated to include contractor information and the on -site inspector. The proposed seed mixes shown on the seeding plan are acceptable. Given the existing tree cover which will likely result in a shaded condition along the southern portion of the subject property, the applicant may wish to consider state mix 36 -211 "Woodland Edge South and West " This seed mix is more likely to successfully establish in the shaded condition. Drainage The revised plans eliminated the most easterly pond. This was accomplished by bringing the drainage from the cul -de -sac on Jeurissen Drive back to pond 2 and shifting the low point on River Rock Drive south. This configuration is preferred for a variety of reasons: it eliminates the need for a retaining wall behind Lots 15 and 16 of Block 3; it reduces the storm water maintenance costs associated with the development, and it minimizes the number of outfalls into pond 2. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 4 Pond 1 will most likely be accessed via the bituminous trail although in order to maintain the pond inlet, it will be necessary at times to access the pond between Lot 5 and Lot 6 of Block 1. Access to pond 2 will be from Jeurissen Drive and the trail within Outlot D. RETAINING WALLS The developer proposes six retaining walls on this site. Retaining Wall A runs parallel to River Rock Drive and will be located on Outlot A. It is 420 feet long and has a maximum height of 9 feet. A 4 -foot, split rail fence will be installed at the top. Walls taller than 6 feet shall not be constructed with boulder rock. The retaining wall in the center of Block 2 runs along the back lot lines of the houses that front River Rock Drive South. This wall is 429 feet long and has a maximum height of 4 feet. A 4- foot, split rail fence will be installed at the top. The retaining wall in Outlot G runs parallel to the western edge of the property. It is 121 feet long with a maximum height of 2.5 feet. Three walls less than 4 feet in height will run parallel to sections of the trail. The intent of these short walls is to delineate the back yards of the homes from the trail and Bluff Creek. The developer may elect to install a different feature, such as landscaping boulders, which would serve the same purpose The retaining wall near Lot 1, Block 1, is 120 feet long, with a maximum height of 3 feet. A 4 -foot split rail fence will be installed on the top. The grading behind the retaining wall near Lot 1, Block 1 must be modified so that water will not drain down the face of the wall. The retaining wall near Lot 13, Block 1 is 204 feet long, with a maximum height of 2.5 feet. A 4 -foot split rail fence will be installed on the top. The retaining wall near Lot 3, Block 5 is 286 feet long, with a maximum height of 2.5 feet. A Homeowners Association must be created to own and maintain all retaining walls and the draintile along the face of Retaining Wall B. SANITARY SEWER AND WATERMAIN The developer proposes to construct new 8 -inch PVC watermain that will connect to the existing watermain that is stubbed out from Bluff Creek Boulevard. SEH's watermain model shows that the watermain pressures would be high enough to cause surge pressures that could damage the system. To lower the water pressure and prevent potential damage by the water hammer effect, the developer's engineer must incorporate pressure reducing valves and surge protection system into the watermain plans. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 5 The developer proposes to construct new 8 -inch sanitary sewer that will connect to the existing 8 -inch PVC sanitary sewer that is stubbed out from Bluff Creek Boulevard. All sanitary sewer shall be constructed with PVC pipe to prevent corrosion damage. Thirty percent (30 %) of the water and sewer hook -ups are due at the time of final plat. The partial hook -up fees will be $143,202.00 ($1,818.00 x 58 units + $651 x 58 units). ASSESSMENTS An assessment for Bluff Creek Boulevard improvements is outstanding for this property. The principal of $601,212.65 was deferred until development and it has been accruing 6% since 2009. As of June 6, 2013, the assessment amount due was $796,302.31. This assessment has been paid. SHORELAND MANAGEMENT DISTRICT That portion of the property within 300 feet of Bluff Creek is considered to be within the Shoreland Management District and is subject to the standards and requirements of this district. The intent of the shoreland rules are to protect the habitat, viewscape and water quality of the waters of the state by setting design standards to this end. The proposed plan is consistent with the requirements of the Shoreland Management District and meets the intent of the shoreland rules. WETLAND PROTECTION A wetland delineation was performed, reviewed and approved in the fall of 2012. The existing conditions plan appears to accurately depict the wetland boundary. No wetland impacts are proposed as part of the design. The wetland is contained within the Bluff Creek Overlay District so the buffer protection will be coincidental to the protection of the Primary Zone. Figure 1. Mitigation area 9, State Project 1017 -12 As part of State Project 1017 -12, T.H.212 Design Build, a large wetland mitigation area was created east of the subject property. This mitigation area included wetland buffer credit extending to the property boundary. Signage will need to be placed along this boundary coincidental to the placement of erosion control measures and prior to any earth - disturbing activities. The city will provide these five signs free of charge so that the developer may place them while placing the other signs. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 6 BLUFF CREEK OVERLAY DISTRICT Much of the property lies within the Bluff Creek Overlay District. This is accurately reflected within the plan set. Efforts were made during the design of this development to avoid disturbances within the primary zone and setback where possible to do so. The only exception is for the placement of the pond outlets. The erosion control plan and landscaping plan have provided for establishment of vegetation in these areas and protection of the area from further impacts. Section 20 -1561 states that one of the intended purposes of the BCOR is "the creation of a greenway connecting Lake Minnewashta Regional Park and the Minnesota River Valley. The greenway will serve as an uninterrupted pedestrian trail, bikeway system, and wildlife corridor affording opportunities for recreation, education, physical fitness and non - motorized transportation ". This must be balanced with the protection of Bluff Creek and the natural resources within the corridor. Staff and the applicant have worked together to achieve this balance. This plan set reflects the product of those discussions. Signage must also be placed to demarcate the corridor. The placement shown on the preliminary erosion control plan, and elsewhere throughout the plan set, is adequate. These signs should be placed concurrently with the perimeter control best management practices before any site grading occurs. STORM WATER MANAGEMENT Under existing conditions, the entire site is tributary to Bluff Creek. The site is a mixture of farmstead, cultivated land, woodlands and seasonally flooded wetlands. The majority of the land area (59 %) discharges directly to Bluff Creek through sheet flow. The most northwesterly portion of the property drains to an existing pond that was constructed with the Preserve at Bluff Creek 1 s` Addition before discharging to Bluff Creek. This area accounts for 15% of the watershed area. The most northeasterly portion of the property accounts for 14% of the watershed and discharges to a large wetland mitigation area, which then discharges into MnDOT right -of -way and then into Bluff Creek. The remaining 12% of the property discharges directly to MnDOT right -of -way and then to Bluff Creek. The design calls for the construction of two new stormwater ponds in which iron - enhanced filtration benches will be constructed. The site will also include sump manholes with SAFL baffles and will utilize the existing pond which was constructed with the Preserve at Bluff Creek 1 'e Addition. Bluff Creek is listed under 303D of the Clean Water Act to have known impairments for turbidity and indices of biological integrity for fish. The stressor identification report indicates that extreme fluctuations in flow and sedimentation due to erosion are the most probable candidate causes. The urbanization of the watershed contributes to this condition by: 1. Increasing the rate and volume of surface runoff into the stream. This increases the frequency and intensity of "flashiness" or bank full events; Todd Gerhardt Camden Ridge - Planning Case 2013 -13 September 9, 2013 Page 7 2. Decreasing the amount of infiltration into the shallow aquifers and subsequently decreasing base flows within Bluff Creek. This is observed annually as the flows fall below detectable levels on monitoring equipment. 3. Increasing the pollutant load being delivered to the creek. The developer and their consulting engineer have engaged city staff in an effort to develop a storm water management plan that will include several best management practices designed specifically to decrease these potential effects on Bluff Creek and improve the quality of the water being discharged to Bluff Creek from this watershed. Under all modeled rainfall events, the post - development runoff rate will be substantially reduced from the pre - development rates. The following table from the Storm Water Management Plan summarizes these reductions. Drainage 2 -Year cfs 10 -Year cfs 100 -Year cfs Area Exi ng Proposed E)dstinR Proposed Existing Proposed 1 8.81 0.83 22.37 2.15 41.78 8.52 2 Pond 8.11 4.81 1.27 19.32 10.53 3.16 35.03 22.30 10.12 3 6.00 3.04 12.97 6.44 22.34 11.51 5 3.83 2.05 9.67 4.28 18.03 7.25 4 1 0.00 0.00 1 0.00 0.00 0.00 0.00 Figure 2. Comparison of runoff rates pre- and post - development City design standards require that water quality treatment is designed to the National Urban Runoff Program (NURP) recommendations. The current General Permit Authorization to Discharge Stormwater Associated with Construction Activity MNR100001 stipulates that development with these characteristics must design the project so that "the water quality volume of one (1) inch of runoff from the new impervious surface....is retained on site (i.e. infiltration or other volume reduction practices) and not discharged to a surface water." Infiltration practices, as discussed earlier, can help ameliorate the impairment issues within Bluff Creek. To this end, the applicant has proposed iron - enhanced filtration/infiltration benches along both newly constructed ponds. These benches will provide a reduction in runoff volume and an increase in infiltration and, quite possibly, base flow. In addition, iron - enhanced filters have been shown to have upwards of 90% phosphorus removal efficacy as they react with the dissolved phosphorus and not just the particulate fraction. The city will provide the applicant with the iron filings. These iron filings will come from iron filings that were left over from the 2012 road reconstruction project. City design standards require that ponds that discharge to impaired waters be constructed with a forebay and be constructed to have a water quality treatment volume in excess of NURP recommendations. The forebay is intended to reduce long -term maintenance costs by decreasing the area of pond dredging to just that forebay rather than the entire pond area. This feature also decreases the potential for re- suspension of particulates that have settled out of suspension. Because of site constraints, the applicant and city staff discussed using sump manholes equipped with baffles designed at the University of Minnesota Saint Anthony Falls Laboratory commonly Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 8 referred to as SAFL Baffle. Several of these have been installed in Chanhassen and have been observed to be functioning. This technology further reduces maintenance costs by increasing the life cycle of the ponds and allowing maintenance to be performed in- house, with city owned equipment and within city right -of -way, thus eliminating the need to access the pond with heavy equipment through an easement on privately owned land. City design standards also require that ponds that discharge to impaired waters be constructed to have a water quality treatment volume in excess of NURP recommendations. The applicant has accommodated in their design as well as shown in the following table from the storm water management plan. Wet Volume Re uirement Basin Volume Required Ac *Ft Volume Provided Ac *Ft 1P 0.67 1.37 2P 1.11 2.03 Figure 3. Proposed volume vs. NURP volume By sizing the ponds in this way, the treatment efficacy will remain higher longer. This will also increase the duration of time before maintenance of the pond is necessary. The borings were performed in November of 2012. On an annual cycle this is the time of year when the water tables are the furthest from the surface. However, no ground water was observed in any of the 10 borings and only boring #3 and #10 showed any secondary indications of subsurface hydrology. Boring 10 is in the location of the proposed westerly pond while boring #3 is in the vicinity of Lot 6 of Block 3. The profile at boring #3 indicates that a buried hydric soil unit exists at about 12 feet below the surface. The proposed grading plan shows fill in this area. Therefore there will be no cut necessary and should groundwater be present it will likely be at an elevation of approximately 973'msl or 12 feet below the proposed low floor elevation. SURFACE WATER MANAGEMENT Surface Water Management trunk storm sewer fees are collected with each subdivision. The fee is based upon buildable land area and is intended to be scalar according to potential surface water runoff contribution. The fee for this development was estimated with the following assumptions: • That Outlots B, C and E would not be assessed as they are used expressly for stormwater best management practices and/or regional trail. • That the land dedicated for public right -of -way is 1.2934 acres and would not be assessed. • That the net density of the site is over 4 units /acre — medium density • That the stormwater best management practices constructed for this project will receive and treat 10.17 acres of watershed. • That the assessable land is 17.01 acres. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 9 The fees are calculated as follows: Figure 4. Surface Water fee calculation table These fees will be due with the final plat. PARKS AND RECREATION The city's comprehensive park plan calls for a neighborhood park to be located within one -half mile of every residence in the city. The proposed Camden Ridge development is located within the park service area of Pioneer Pass Park. Construction of the 8.7 -acre Pioneer Pass Park site is currently underway and Phase 1 of development is expected to be complete in 2014. One of the most anticipated trail extensions within the city is the north/south Bluff Creek Corridor Pedestrian Trail that extends from Lyman Boulevard south to Pioneer Trail. The proposed Camden Ridge development is poised to complete this extension. The proposed development will construct a trail starting at the current southern terminus of the Bluff Creek Trail and extending south — stopping at a location north of TH 212. In order to complete a link to Pioneer Trail, the city would like to work with the property owner of Outlots B, C and D, Jeurissen Ridge to extend the trail under the TH 212 bridge to a point connecting with the existing pedestrian trail along Pioneer Trail. The developer shall pay parks fees of $315,600 (32 single - family x $5,800 = $185,600 plus 26 twinhome units x $5000 = $130,000) prior to recording the final plat. COMPLIANCE TABLE BASE FEE ACRES TOTAL WATER QUANTITY $5,590 17.01 $95,099.32 WATER QUALITY $2,830 17.01 $48,145.09 SUBTOTAL $143,244.11 BASE CREDIT ACRES TREATED (Feet) WATER QUALITY CREDIT $2,830(0.5 ) 10.17 $14,390.55 TOTAL SWM trunk sewer fee $128,853.86 Figure 4. Surface Water fee calculation table These fees will be due with the final plat. PARKS AND RECREATION The city's comprehensive park plan calls for a neighborhood park to be located within one -half mile of every residence in the city. The proposed Camden Ridge development is located within the park service area of Pioneer Pass Park. Construction of the 8.7 -acre Pioneer Pass Park site is currently underway and Phase 1 of development is expected to be complete in 2014. One of the most anticipated trail extensions within the city is the north/south Bluff Creek Corridor Pedestrian Trail that extends from Lyman Boulevard south to Pioneer Trail. The proposed Camden Ridge development is poised to complete this extension. The proposed development will construct a trail starting at the current southern terminus of the Bluff Creek Trail and extending south — stopping at a location north of TH 212. In order to complete a link to Pioneer Trail, the city would like to work with the property owner of Outlots B, C and D, Jeurissen Ridge to extend the trail under the TH 212 bridge to a point connecting with the existing pedestrian trail along Pioneer Trail. The developer shall pay parks fees of $315,600 (32 single - family x $5,800 = $185,600 plus 26 twinhome units x $5000 = $130,000) prior to recording the final plat. COMPLIANCE TABLE Lot Lot Allowable Block Lot Lot Area Width Depth Impervious Notes (SF) (Feet) (Feet) Area (SF) *75 feet in Shoreland Single - Family 9,000 70* 130 District Twin Home 5,100 32 120 1 1 90 131 4,606 2 3,273 90 148 4,606 3 j12,272 0,417 72 133 4,606 4 2,157 80 133 4,606 Corner lot Todd Gerhardt Camden Ridge - Planning Case 2013 -13 September 9, 2013 Page 10 Lot Lot Allowable Block Lot Lot Area Width Depth Impervious Notes (SF) (Feet) (Feet) Area (SF) *75 feet in Shoreland Single- Family 9,000 70* 130 District Twin Home 5,100 32 120 5 12,272 91 135 4,606 6 14,049 91 154 4,606 Shoreland District 7 15,384 96 156 4,606 Shoreland District @ 85 ft. at setback, Bluff Creek primary 8 15,504 66 @ 134 4,606 zone and Shoreland District @ 84 ft. at setback, 9 13,836 57 @ 130 4,606 Bluff Creek primary zone and Shoreland District @ 88 ft. at setback, Bluff Creek primary 10 16,767 60 @ 132 4,606 zone and Shoreland District Bluff Creek primary 11 15,592 116 131 4,606 zone and Shoreland District Bluff Creek primary 12 15,997 93 176 4,606 zone and Shoreland District Bluff Creek primary 13 14,160 108 152 4,606 zone and Shoreland District Bluff Creek primary 14 13,043 120 133 4,606 zone and Shoreland District 2 1 11,164 86 132 3,984 Corner lot 2 10,009 77 133 3,984 3 10,449 75 138 3,984 4 10,983 86 142 3,984 5 11,244 78 146 3,984 6 11,541 93 148 3,984 7 11,234 93 143 3,984 8 10,587 77 140 3,984 9 10,427 73 135 3,984 Todd Gerhardt Camden Ridge - Planning Case 2013 -13 September 9, 2013 Page 11 Block Lot Lot Area (SF) Lot Width (Feet) Lot Depth (Feet) Allowable Impervious Area (SF) Notes Single - Family 9,000 70* 130 *75 feet in Shoreland District Twin Home 5,100 32 120 10 10,731 71 132 3,984 11 10,205 72 130 3,984 12 10,005 77 134 3,984 13 11,848 95 132 3,984 Corner lot 3 1 14,003 56 161 3,051 twin home 2 6,813 43 160 3,051 twin home 3 6,787 42 160 3,051 twin home 4 7,782 42 160 3,051 twin home 5 9,567 34 170 3,051 twin home 6 11,114 34 177 3,051 twin home 7 7,560 31 141 3,051 twin home 8 5,920 43 139 3,051 twin home 9 6,157 42 145 3,051 twin home 10 6,851 47 147 3,051 twin home 11 7,999 33 151 3,051 twin home 12 8,865 35 159 3,051 twin home 13 8,338 40 160 3,051 twin home 14 6,656 43 156 3,051 twin home 15 6,520 42 154 3,051 twin home 16 9,523 83 147 3,051 Corner lot, twin home 4 1 5,223 42 124 1 3,051 twin home 2 5,305 47 124 3,051 twin home 3 6,262 66 127 3,051 twin home 4 6,765 64 138 3,051 twin home 5 8,160 93 135 3,051 twin home 6 8,467 100 127 3,051 twin home 7 1 6,131 56 129 1 3,051 twin home 8 5,177 43 126 3,051 twin home 9 5,129 43 125 3,051 twin home 10 7,152 60 125 3,051 Corner lot, twin home 5 1 13,435 153 133 4,606 Bluff Creek primary zone and Shoreland District Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 12 Lot Lot Allowable Block Lot Lot Area Width Depth Impervious Notes (SF) (Feet) (Feet) Area (SF) *75 feet in Shoreland Single - Family 9,000 70* 130 District Twin Home 5,100 32 120 Bluff Creek primary 2 13,356 87 141 4,606 zone and Shoreland District Bluff Creek primary 3 14,745 86 148 4,606 zone and Shoreland District Bluff Creek primary 4 13,237 106 142 4,606 zone and Shoreland District Bluff Creek primary 5 12,949 61 166 4,606 zone and Shoreland District Outlot 91,582 2.1 ac. Open Space A Outlot 15,875 0.36 ac. Open Space B Outlot 1.36 ac. Stormwater C 59,337 pond and Trail Outlot 7,148 0.16 ac. Trail D Outlot .67 ac. Stormwater E 29,047 and Outlot 7,747 0.18 ac. Trail F Outlot 0.86 ac. Noise wall G 37,511 and Open Space ROW 191,803 4.4 ac. TOTAL 1,037,148 23.8 ac. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 13 The PUD ordinance requires setbacks from roadways and property lines. The following table displays those setbacks. * The entire development, including the public and private streets and Outlots, may not exceed 35 percent hard coverage. Individual lots may exceed the 35 percent site coverage. Lots within the shoreland district may not exceed 25 percent site coverage on average. Lot coverage may not exceed those established in the compliance table. REVIEW CONDITIONS OF APPROVAL Building Conditions: 1. Demolition permits are required for the removal of any existing structures. *This condition still applies. 2. Buildings maybe required to be designed by an architect and /or engineer as determined by the Building Official. *This condition still applies. 3. A final grading plan and soils report must be submitted to the Inspections Division before permits can be issued. *This condition still applies. Setback Standards Highway 212 50 feet Exterior (Perimeter) Lot Lines 50 feet Front Yard 25 feet Front Yard (side street) 20 feet Side Yard: garage side and house side 7.5 feet (minimum separation between buildings is 15 feet Rear Yard 25 feet Hard Surface Coverage 35%* Bluff Creek Primary zone boundary (BCO) 40 feet with the first 20 feet as buffer Minimum Lot Dimensions Standards Single-family detached area 9,000 square feet Single-family detached (lot width ) 70 feet 75 feet in shoreland district Single-family detached (lot depth) 130 feet Twinhome lot area per unit) 5,100 square feet Twinhome lot (lot width) 32 feet Twinhome lot (lot depth) 120 feet * The entire development, including the public and private streets and Outlots, may not exceed 35 percent hard coverage. Individual lots may exceed the 35 percent site coverage. Lots within the shoreland district may not exceed 25 percent site coverage on average. Lot coverage may not exceed those established in the compliance table. REVIEW CONDITIONS OF APPROVAL Building Conditions: 1. Demolition permits are required for the removal of any existing structures. *This condition still applies. 2. Buildings maybe required to be designed by an architect and /or engineer as determined by the Building Official. *This condition still applies. 3. A final grading plan and soils report must be submitted to the Inspections Division before permits can be issued. *This condition still applies. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 14 4. Retaining walls over four feet high require a permit and must be designed by a professional engineer. *This condition still applies. 5. Each lot must be provided with separate sewer and water services. *This condition still applies. 6. The applicant and/or their agent shall meet with the Inspections Division as early as possible to discuss plan review and permit procedures. *This condition still applies. 7. Submit proposed street names to Chanhassen Building Official and Chanhassen Fire Marshal for review and approval. *This condition has been met. Based on review of the final plat, the following condition shall be added: 8. Provide a 1:200 "clean" plat drawing. Engineering Conditions: 1. The developer must obtain right -of -way for the part of River Rock Road that connects to Bluff Creek Boulevard. *This condition has been met. 2. The proposed "Easement Detail" must be revised to include how the easements around the perimeter of the twinhome lots will be platted. *This condition has been met. 3. The developer's engineer must adjust the grading on the trail near Outlot F so that it will meet ADA standards. *This condition has been met. 4. The contours near the northwest corner of Pond 2, between Lots 6 and 7 must be smoothed out. *This condition has been met. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 15 5. Additional information needs to be noted (such as elevation points between the lots) between lots on the north side of Street B to show the grading will allow water to drain away from the structures. *This condition has been met. 6. The final plans must note the survey benchmark on the plan set. *This condition has been met. 7. The final plans must note the existing and proposed elevations at the corners of each lot. *This condition has been met. 8. The grading behind all the retaining walls must be modified so that water will not drain down the face of the wall. *This condition shall be modified as follows: The grading behind all the retaining walls near Lot 1, Block 1 must be modified so that water will not drain down the face of the wall. 9. Walls taller than 6 feet shall not be constructed with boulder rock. *This condition has been met. 10. Retaining Wall B must be moved so that it is outside the drainage and utility easement at the back of the lots. *This condition has been met. 11. A Homeowners Association must be created to take ownership of all retaining walls and the draintile along the face of Retaining Wall B. *This condition still applies. 12. Local streets must be within a 60 -foot wide right -of -way. *This condition has been met. 13. At final plat, the Engineering Department will review the profile of Street A between stations 2 +00 and 4 +00 to ensure the profile meets the minimum length requirements for vertical curves. *This condition shall be modified as follows: Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 16 At fiae4 plat the E..gineefin° Depaftmeat will .° ° .. The profile of Street Henry Court must be revised betty°°° 4 «: E)as 2 ! 00 and 4+00 to ensure the profile meets the minimum length requirements for vertical curves. 14. The proposed centerline grade at the intersection of River Rock Drive and Street A must not be greater than 3 %. *This condition shall be modified as follows: The proposed centerline grade at4he within 30 feet of an intersection of Rive_ Reek Drive array Street must not be greater than 3 %. 15. The existing driveway access to TH 212 must be closed except for access for agricultural purposes only on Outlot C, Jeurissen 1st Addition. An access easement across Outlot B, Jeurissen 1st Addition, shall be recorded which shall follow the existing driveway alignment with a width of approximately 26 feet. Said easement shall be vacated should alternate access to Outlot C, Jeurissen l st Addition become available. *This condition applies to the Jeurissen Ridge plat. 16. The developer's engineer must design a Street C typical section. *This condition shall be modified as shown in Condition 14 above. 17. The development is adjacent to Bluff Creek Boulevard and is therefore subject to the arterial collector fee at the time of final plat for Camden Ridge. The fee shall be $55,030.56 ($2,400 x 22.9294 acres of Outlot A, Jeurissen 1st Addition). *This condition shall be modified as follows: The development is adjacent to Bluff Creek Boulevard and is therefore subject to the arterial collector fee at the time of final plat for Camden Ridge. The fee shall be $32,904.00 55,^�S090.56 ($2,400 x 22.9294 13.71 acres of Outlot A, Jeurissen 1" Addition). 18. The developer's engineer must incorporate pressure- reducing valves and a surge protection system into the watermain plans. *This condition still applies. 19. The developer's engineer will ensure that CBMH -102 does not conflict with the nearby watermain. *This condition has been met. 20. Unless the Bluff Creek Boulevard Improvements assessment, City Project 06 -05, levied against the property described on Exhibit "A" is paid in full before the plat is recorded the Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 17 assessment is reapportioned against Outlot A (Jeurissen Ridge). As of June 6, 2013, the assessment amount with accrued interest was $796,302.31. *This condition has been met. 21. Water and sewer hook -up fees must be paid at the time of final plat. *This condition shall be modified as follows: Water and sewer hook -up fees in the amount of $143,202 must be paid c m�ue time a with the final plat and is calculated as follows: SAC 58 units x $651 /unit = $37,758, WAC 58 units x $1,818 /unit = $105,444. The remaining 70 percent of the fees must be paid with the building permit at the rate in effect at that time. 22. Preserving 60 feet of right -of -way to the property straight north of Camden Ridge. *This condition has been met. Based on review of the final plat documents, staff is recommending that the following conditions be added: 23. The Access Path shall be shifted to the east to preserve the Bluff Creek primary zone. 24. All sanitary sewer shall be constructed of PVC pipe to prevent corrosion. 25. The trail profile shall be revised to have a minimum slope of 1.0 percent to facilitate drainage on the bituminous pavement. Fire Conditions: 1. A three -foot clear space must be maintained around fire hydrants. *This condition still applies. 2. Temporary street signs must be installed prior to home construction. *This condition still applies. 3. No burning permits will be issued. Any trees removed must either be chipped on site or removed from site. *This condition still applies. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 18 4. Water mains shall be made serviceable prior to combustible construction. *This condition still applies. 5. Posts, fences, utility boxes etc. shall not be placed near fire hydrants which would hinder firefighters to quickly locate and /or operate fire hydrants in a safe manner. *This condition still applies. Natural Resources Conditions: 1. The applicant shall increase bufferyard plantings to meet minimum requirements. *This condition still applies. 2. The applicant shall plant a minimum of 130 trees in the development. *This condition still applies. 3. The applicant shall diversify the plant schedule so that no one species comprises more than one third of the total number of trees. *This condition has been met. 4. The applicant shall specify vegetation proposed for Outlots A, B and C. *This condition has been met. 5. The applicant shall submit a revised landscape plan to the city prior to final approval. *This condition still applies. 6. The applicant shall preserve trees #1301, 1302, 1303. These trees along with trees #1393- 1398 shall be protected by fencing prior to and during any grading or construction activities. *This condition has been met. 7. The developer shall install signage at lot lines to demarcate the Bluff Creek Primary Zone. *This condition still applies. Parks Conditions: 1. Full park dedication fees shall be collected per city ordinance in lieu of requiring parkland dedication. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 19 *This condition shall be modified as follows: X11 Park dedication fees of $315,600 shall be collected per city ordinance in lieu of requiring parkland dedication. 2. Construction of Bluff Creek Trail from its current southerly terminus, extending between the new homes and Bluff Creek to a terminus point at TH 212. The developer shall provide design, engineering, construction and testing services required of the "Bluff Creek Trail." All construction documents, including material costs, shall be delivered to the Park and Recreation Director and City Engineer for approval prior to the initiation of each phase of construction. The trail shall be 10 feet in width, surfaced with asphalt and constructed to meet all city specifications. The applicant shall be reimbursed by the City for the cost of the aggregate base, asphalt surfacing, and stone water systems utilized to construct the trail. This reimbursement payment shall be made upon completion and acceptance of the trail and receipt of an invoice documenting the actual costs for the construction materials noted. Labor and installation, design, engineering and testing services are not reimbursable expenses. *This condition still applies. Planning Conditions: 1. The developer shall pay $6,285.00 as its portion of the 2005 AUAR prior to recording the final plat. *This condition still applies. 2. The developer shall prepare a noise analysis for noise generated by traffic on Highway 212. The analysis shall identify appropriate noise mitigation measures to meet noise standards for residential homes as specified by the Minnesota Pollution Control Agency, which shall be implemented by the developer. *This condition shall be modified as follows: The developer ,.hall .. a neise ....1. sis for- noise g ...,40.7 by 4raf'fie on Highway 21'1 The Camden Ridge Chanhassen, Minnesota Traffic Noise Assessment prepared for 1L Pioneer Engineering by David Brauslau Associates, Inc. dated August 2, 2013 aaal-ysis shall identi identified appropriate noise mitigation measures to meet noise standards for residential homes as eified by the r imnegst„ u,.11utiea Ge 4rel A..o. ey, ,..l.:a shall be implemented by the developer. Note: The Assessment specified that with the construction of the proposed noise wall, the use of year -round climate control for homes and construction standards that provide an Exterior - Interior Noise Reduction of 30 dBA standard will provide the appropriate level of noise mitigation. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 20 3. The Bluff Creek Overlay District primary zone, Outlot `B ", shall be conveyed to the City by warranty deed free and clear of any encumbrances or a preservation easement acceptable to the City shall be established over Outlot B before the plat is recorded. *This condition applies to the Jeurissen Ridge plat. 4. Before any development plans are submitted for Outlot C, the property owner shall provide appropriate technical information, including but not limited to a topographical survey, flora and fauna survey and soil data deemed necessary for the city to determine the exact watershed zone boundary on Outlot C, Jeurissen 151 Addition. Data for watershed zone delineation shall be generated and provided by a qualified professional specializing in watershed management, environmental science or other related profession. Development of Outlot C Jeurissen I" Addition would be inconsistent with the adopted Alternate Urban Areawide Review, AUAR. Any development would need to conduct additional environmental documentation or review or request an amendment to the 2005 AUAR. *This condition applies to the Jeurissen Ridge plat. 5. The property owner must advise the city of the intended use of Outlot C, Jeurissen 1" Addition, and how it shall be accessed. This Outlot may not be developable or accessible in the future. *This condition applies to the Jeurissen Ridge plat. 6. Final plat approval will be contingent on the developer resolving the access issue. Either an access easement or right -of -way must be in place prior to any site development. *This condition has been met. 7. Individual lots may not exceed the maximum hard cover per lot established in the compliance table. *This condition still applies. Water Resources Conditions: Land disturbance within the first twenty feet of the Bluff Creek Overlay District setback shall not be allowed unless the applicant can demonstrate that the goal cannot be achieved without the proposed disturbance. *This condition has been met. 2. A mitigation/restoration plan must be provided for any disturbance within the Bluff Creek Overlay District or setback from the BCOR. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 21 *This condition has been met. 3. Trail must be aligned to minimize the encroachment into the BCOR primary zone and minimize loss of natural vegetation and habitat. *This condition has been met. 4. Efforts must be made to minimize the number of inlets into each pond. *This condition has been met. 5. The proposed ponds must be designed with a forebay. *This condition has been met. 6. The plans must demonstrate how water quality basin #1 and water quality basin #3 will be accessed. This includes all inlets, outlets and filtration benches as well as sediment removal from forebay and water quality volume. *This condition has been met. 7. The stormwater design shall, to the greatest extent practicable, seek to maximize infiltration, extend detention times and protect Bluff Creek from scour and other erosive conditions. *This condition has been met. 8. The applicant must evaluate downstream flow conditions as indicated in Section 19 -144. *This condition has been met. 9. A Surface Water Pollution Plan and all required elements must be provided to the city for review. This plan must be compliant with NPDES requirements as well as the requirements of Chapter 19 of city code. *This condition shall be modified as follows: A Surface Water Pollution Prevention Plan shall be updated to include contact information of responsible parties and A reqtfired elements ffv:st be pFevidea to the ei ., for r-e-Aew. This plan ffiust be eeffipliant with NPDES Fequir-emeffts as well as the 10. SWMP trunk fees due at final plat are estimated to be $104,930.25. *This condition shall be modified as follows: Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 22 SWMP trunk fees due at final plat are estiffteted calculated to be $128,853.86 S104,930,25 11. The development must comply with the MN Rules chapter 6120 and the DNR must issue their concurrence to this effect. *This condition still applies. 12. No alterations are allowed within the primary corridor or within the first 20 feet of the setback from the primary corridor. Grading activities have been observed within this area along the south side of Bluff Creek. The applicant should submit a plan for the revegetation of this area that incorporates native plants and is consistent with the City's Bluff Creek Natural Resources Management Plan Appendix C. Any such areas that have been disturbed through the removal or addition of soils material prior to approval shall be addressed prior to commencement of other grading activities but no later than seven (7) days from approval. *This condition still applies. RECOMMENDATION Staff recommends approval of the final plat for Camden Ridge subject to the following conditions: Building Conditions: 1. Demolition permits are required for the removal of any existing structures. 2. Buildings may be required to be designed by an architect and/or engineer as determined by the Building Official. 3. A final grading plan and soils report must be submitted to the Inspections Division before permits can be issued. 4. Retaining walls over four feet high require a permit and must be designed by a professional engineer. 5. Each lot must be provided with separate sewer and water services. 6. The applicant and /or their agent shall meet with the Inspections Division as early as possible to discuss plan review and permit procedures. 7. Provide a 1:200 "clean" plat drawing. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 23 Engineering eering Conditions: 1. The grading behind the retaining wall near Lot 1, Block 1 must be modified so that water will not drain down the face of the wall. 2. A Homeowners Association must be created to own and maintain of all retaining walls and the draintile along the face of Retaining Wall B. 3. The profile of Henry Court must be revised to ensure the profile meets the minimum length requirements for vertical curves. 4. The proposed centerline grade within 30 feet of an intersection must not exceed 3 %. 5. The Access Path shall be shifted as far east as practical to reduce impact to the Bluff Creek primary zone. 6. The trail profile shall be revised to have a minimum slope of 1.0 percent to facilitate drainage on the bituminous pavement. 7. The developer's engineer must incorporate pressure reducing valves and a surge protection system into the watermain plans. 8. All sanitary sewer shall be constructed with PVC pipe to prevent corrosion damage. 9. The development is adjacent to Bluff Creek Boulevard and is therefore subject to the arterial collector fee at the time of final plat. The fee shall be $32,904.00 ($2,400 x 13.71 developable acres). 10. Water and sewer hook -up fees in the amount of $143,202 must be paid with the final plat and are calculated as follows: SAC 58 units x $651 /unit = $37,758, WAC 58 units x $1,818 /unit = $105,444. The remaining 70 percent of the fees must be paid with the building permit at the rate in effect at that time. Fire Conditions: 1. A three -foot clear space must be maintained around fire hydrants. 2. Temporary street signs must be installed prior to home construction. 3. No burning permits will be issued. Any trees removed must either be chipped on site or removed from site. 4. Water mains shall be made serviceable prior to combustible construction. 5. Posts, fences, utility boxes etc. shall not be placed near fire hydrants which would hinder firefighters to quickly locate and /or operate fire hydrants in a safe manner. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 24 Natural Resources Conditions: 1. The applicant shall increase bufferyard plantings to meet minimum requirements. 2. The applicant shall plant a minimum of 130 trees in the development. 3. The applicant shall submit a revised landscape plan to the city prior to final approval. 4. The developer shall install signage at lot lines to demarcate the Bluff Creek Primary Zone. Parks Conditions: 1. Park dedication fees of $315,600 shall be collected per city ordinance in lieu of requiring parkland dedication. 2. Construction of Bluff Creek Trail from its current southerly terminus, extending between the new homes and Bluff Creek to a terminus point at TH 212. The developer shall provide design, engineering, construction and testing services required of the "Bluff Creek Trail." All construction documents, including material costs, shall be delivered to the Park and Recreation Director and City Engineer for approval prior to the initiation of each phase of construction. The trail shall be 10 feet in width, surfaced with asphalt and constructed to meet all city specifications. The applicant shall be reimbursed by the City for the cost of the aggregate base, asphalt surfacing, and storm water systems utilized to construct the trail. This reimbursement payment shall be made upon completion and acceptance of the trail and receipt of an invoice documenting the actual costs for the construction materials noted. Labor and installation, design, engineering and testing services are not reimbursable expenses. Planning Conditions: The developer shall pay $6,285.00 as its portion of the 2005 AUAR prior to recording the final plat. 2. The Camden Ridge Chanhassen, Minnesota Traffic Noise Assessment prepared for Pioneer Engineering by David Brauslau Associates, Inc. dated August 2, 2013 identified appropriate noise mitigation measures to meet noise standards for residential homes shall be implemented by the developer. Note: The Assessment specified that with the construction of the proposed noise wall, the use of year -round climate control for homes and construction standards that provide an Exterior - Interior Noise Reduction of 30 dBA standard will provide the appropriate level of noise mitigation. 3. Individual lots may not exceed the maximum hard cover per lot established in the compliance table. Todd Gerhardt Camden Ridge — Planning Case 2013 -13 September 9, 2013 Page 25 Water Resources Conditions: 1. A Surface Water Pollution Prevention Plan shall be updated to include contact information of responsible parties. 2. SWMP trunk fees due at final plat are calculated to be $128,853.86. 3. The development must comply with the MN Rules chapter 6120 and the DNR must issue their concurrence to this effect. 4. No alterations are allowed within the primary corridor or within the first 20 feet of the setback from the primary corridor. Grading activities have been observed within this area along the south side of Bluff Creek. The applicant should submit a plan for the revegetation of this area that incorporates native plants and is consistent with the City's Bluff Creek Natural Resources Management Plan Appendix C. Any such areas that have been disturbed through the removal or addition of soils material prior to approval shall be addressed prior to commencement of other grading activities but no later than seven (7) days from approval. ATTACHMENTS 1. Reduced Copy Final Plat. 2. Traffic Noise Assessment dated August 2, 2013. g: \plan\2013 planning eases\2013 -13 camden ridge \camden ridge final plaAstaff report camden ridge 1p.doc CAMDEN RIDGE R. Nl M.6Y IIESE.1,di The, US xemv Cvpvm'm. I i...— lnv INMne X.11.1 A R... RODS..., m,al A. NmIaR IASS, mm,.y R, w. ,a.,m. qw. ,D.,ml. wm, f,dd," rv.pE m m CANGEx ROOF wY m t D O I I., P q. — Im IN µRe I ..1 111....1. w M— m mu pe Iv visme Y Pu,pmn m Y µPoo e,lev mn _ pyR.— Cvidd,,f , . OO I — ,vn, nm .—u IM•. peunla 1e Ye vgrtE " iu STAR C£ ..EWTi LWNtt C£ me ,aayr.p wbu u• emm�erym Dam. vu.1 Ne .,Dw.xm, I oIld— eapom,u., o. hell .I me . Cwnly. Nmneml. NY Cwnm:ew'm EvpYea SUNbEXWS CERTIFICATE POLE, N m`[Nalm,m^Id 1i1, R., ID I, a, .ne Imtlee m tnevw.l .ne ,D.1 If P.q....y .rt ahem III pM.e en ue PnI, a of ,nx .w,Ilkelm wv uwn uNnveow Im— X.[93399 u w mm $TAX C MINNESOTA CWNtt F rnv Iwpavp Surcp'e CnN14mv DY Pu., l Xennm, Wnem,. u.e..e N. 41ffRA III w4n.a.didie D.b. m• ux NY C.mmeem u.c.. c..mY. M,mm,. W HASSEN. NINNEmiA M.. III mm De m. <RY [ R .... In .nn dll- -.r.< eY m. 'dy....e m... ,m,m m Rm Iw, mmm.no ,. u.m.•m. .• If amM. sm. LCIINtt SJflAEVOR, Caner Ccunly, Minne•oty I I. am,w b; NFnneu m.x a, Inl. In. olm n.. ex di ILI• _ wy e, C NW AUOROR/3REAAAX R, Cww, Cwn \y, Minn.eolo Dv l.m D.ryge F _ me b wv D.rc hem P.b Iv Ime .—A,d w Inl, w.l. Dv,w mn If Lwe Edna, Cw1Y A.61w/r,.mu,v .Tf` REMOTER, C.— Cwnly, MR. —RdI I_..KK. 1.1 .1 xa IOM ..e fish,na _ eq el ii clTV R SSECEIVEDEn 4UG 0 2 2013 CHANHASSEN PLANNING DEPT PMNEERenenwting SCANNED .EYe HE "'RISERVI AT �RE9< 1ST A'.21 "'.O." RUFF 59896101 350.00 i_._. .... .......... SECnO 25, rW 116. Ra. zi L&A OONi MAP CAMDEN RIDGE .m�essc nix. na au.» 1004.18 m PI8NEERengineming SCANNED O 1 'r c� r� PI8NEERengineming SCANNED of � � 0 A A. OUTLOT A 1 2 3 x 4 i n s -i 5 OUTIOT C 6 7 6 10 CAMDEN RIDGE AREA SKETCH RIVER ROCK DRIVE SOUTH ,_>< t 2 5 3 AREA SUMMARY BLOIX 1 194.123 SF. 4.4700 AC, BIOCx 3 = H0.427 V. 3.2239 AC. OLOOR 3 130.455 SF. 29946 AC, 610IX 4 53.11, SF. 1.9638 AC. BLOOM 5 = 67.722 SF. 1.5547 AC. W LOT AREA = 597.098 SF. 1}1010 AC. ,OTAL WROT AREA a 248,247 SE 56988 AC. TOTAL R/ AREA = 191.803 SE 4AC31 AC. TOTAL AREA = 1,037,148 SF, 23.8089 AC. 1 v 2 3 4 3 5 6 7 V diM 5 a1n 6 �4 T — 11 12 13 14 o, - 15 16 o T T DurNoT 6 PMNEERenenwing SCANNED CITY OF CHANHASSEN RECEIVED AUG 0 2 2013 CHANHASSEN PLANNING DEPT Camden Ridge Chanhassen, Minnesota TRAFFIC NOISE ASSESSMENT Prepared for Pioneer Engineering. by David Braslau Associates, Inc. 6603 Queen Avenue S. Suite N Richfield, MN 55423 Tel: 612 - 331 -4571 Fax: 612-331-4572 Eml: david @braslau.com Dr. David Braslau, President 2 August 2013 scwMil � Camden Ridge Traffic Noise Assessment Table of Contents 1.0 INTRODUCTION ............................................................................... ..............................1 1.1. Objectives of this Noise Assessment ............................................... ............................... 1 1.2. Site Location and Layout ................................................................. ............................... 1 1.3. Minnesota Noise Standards .............................................................. ............................... 1 1.4. Report Components .......................................................................... ............................... 4 2.0 METHODOLOGY FOR ANALYZING HIGHWAY NOISE ....... ............................... 5 2.1. Noise Modeling Assumptions .......................................................... ............................... 5 3.0 TRAFFIC NOISE LEVELS .............................................................. ............................... 7 3.1. Predicted Noise Levels ..................................................................... ............................... 7 3.2. Compliance with State Standards for the 6 -7 AM (nighttime) Period ............................ 9 3.3. Construction needed to provide an Exterior - Interior Noise Reduction of 30 dBA....... 10 4.0 SUMMARY OF FINDINGS .............................................................. .............................11 Associates, Inc. Camden Ridge Traffic Noise Assessment List of Figures Figure1.1 Site Location ........................................................................... ............................... 2 Figure 1.2 Site Layout and Grading Plan ............................................... ............................... 3 Figure 2.1 Location of Receptor Sites and Proposed Berm and Noise Wall ...................... 6 List of Tables Table 1.1 Minnesota State Noise Standards for Residential Land Uses (NAC -1) ...........1 Table 3.1 Predicted L10 for the PM Peak Hour .................................. ............................... 7 Table 3.2 Predicted L10 for the 6 -7 AM Hour ..................................... ............................... 8 Table 3.3 6 -7 AM Level s relative to the NAC -2 Standards ................ .............................10 David Braslau Associates, Inc. Camden Ridge Traffic Noise Assessment 1.0 INTRODUCTION 1.1. Objectives of this Noise Assessment This Noise Assessment evaluates the potential impacts of noise from Trunk Highway 212 on the proposed Camden Ridge residential development in Chanhassen, Minnesota. Projected traffic noise levels from TH 212 are compared with the Minnesota daytime and nighttime noise standards to determine the potential for noise impacts and effectiveness of the proposed noise wall on top of the existing berms. The exterior- interior noise attenuation provided by the proposed building construction is assumed for typical construction in Minnesota and compared with the exemption provisions contained in the Minnesota rules. 1.2. Site Location and Layout Location of the Camden Ridge development within the City of Chanhassen is shown in Figure 1.1. The development and grading plan is shown in Figure 1.2. Noise impacts have been evaluated for receptors at the ground floor and upper floor levels. 1.3. Minnesota Noise Standards The Minnesota State Noise Standards for residential land uses are presented in Table 1.1. Residential land uses are included in the NAC -1 (Noise Area Classification -1) under Minnesota Rule 7030.0040. Table 1.1 Minnesota State Noise Standards for Residential Land Uses (NAC -1) L10 is the level exceeded 10% or 6 minutes of an hour. L50 is the level exceeded 50% or 30 minutes of an hour. The L101evel is used as the primary indicator of traffic noise impact since it accurately reflects the potential impact of traffic. Braslau Associates, Inc. Page 1 Daytime (7:00 am to .00m Nighttime (10:00 pm to 7:00 am L10 65 dBA 55 dBA L50 60 dBA 50 dBA L10 is the level exceeded 10% or 6 minutes of an hour. L50 is the level exceeded 50% or 30 minutes of an hour. The L101evel is used as the primary indicator of traffic noise impact since it accurately reflects the potential impact of traffic. Braslau Associates, Inc. Page 1 Camden Ridge Traffic Noise Assessment Figure 1.1 Site Location Source: Pioneer Engineerng David Braslau Associates, Inc. Page 2 Camden Ridge Traffic Noise Assessment Source: Pioneer Engineering I: t. i- L,L{ , it q. Figure 1.2 Site Layout and Grading Plan i David Braslau Associates, Inc. Page 3 Camden Ridge Traffic Noise Assessment 1.4. Report Components Section 2.0 of the report describes the methodology and assumptions used for analyzing traffic noise. Section 3.0 of the report addresses projected traffic noise and compliance with state noise standards. Section 4.0 presents a summary of findings. David Braslau Associates, Inc. Page 4 Camden Ridge Traffic Noise Assessment 2.0 METHODOLOGY FOR ANALYZING HIGHWAY NOISE Noise levels from TH 212 have been predicted using the MinnNoise highway noise model upon MnDOT traffic counts on TH 212. Noise levels are evaluated at receptors facing the highway at each of the proposed lots 5 feet above ground level where outdoor activity can be expected and also at the upper floors of homes with living and sleeping rooms. Predicted traffic noise levels are compared with the Minnesota state noise standards to determine compliance with the standards. 2.1. Noise Modeling Assumptions Model geometry was based upon the grading plan with adjacent highway layout and elevations shown on Figure 2.1. Vehicle mix and volumes were taken from the MnDOT MinnNoise model input for TH 212 just east of the project and adjusted based upon the 2012 volume of 41,500 vehicles per day. An 8 foot high noise wall on a berm up to 4 feet in height, depending upon location, is proposed along the entire property fronting TH 212 as shown on Figure 2.1. Noise receptors have been assumed 5 feet above ground level and at the upper floors of the lots closest to TH 212.. Some limited shielding of noise is assumed to be provided by homes. David Braslau Associates, Inc. Camden Ridge Traffic Noise Assessment 5/65./�6�.-yj Ir �J �J 1 , I5 n6 19/14 Figure 2.1 Location of Receptor Sites and Proposed Berm and Noise Wall David Braslau Associates, Inc. Page 6 Camden Ridge Traffic Noise Assessment 3.0 TRAFFIC NOISE LEVELS 3.1. Predicted Noise Levels Predicted daytime L10 noise levels at ground level receptors (5 feet above ground elevation) and the upper floor at each of the receptor sites are shown in Table 3.1. The last two columns show the predicted L101evel relative to the daytime standard of 65 dBA. All levels are expressed in dBA (A- weighted decibels). Location of the receptor sites is shown on Figure 3.1. Table 3.1 Predicted L10 for the PM Peak Hour It can be seen from the table that all of the outdoor ground floor receptors are predicted to be below the daytime noise standard. Levels at the upper floors upper floor levels are generally several dBA above the daytime standard but are not intended for outdoor uses. With appropriate home construction required for compliance with the nighttime standard (see discussion in Section 3.2, the applicable L10 standard will be 70 dBA, so that these homes will be in compliance with the state noise standards. David Braslau Associates, Inc. Page 7 L10 PM Period Re Day Standard Receptor Ground Flr Upper Flr Ground Flr Upper Flr LOT1 -3 62.9 64.4 -2.1 -0.6 LOT1 -4 64.2 66.3 -0.8 1.3 LOT1 -5 63.4 68.6 -1.6 3.6 LOT2 -15/16 62.8 67.8 -2.2 2.8 LOT2 -13/14 1 63.2 67.8 1 -1.8 2.8 LOT2 -11/12 63.2 67.4 -1.8 2.4 LOT2 -9/10 62.4 66.4 -2.6 1.4 LOT2 -7/8 61.2 65.6 -3.8 0.6 LOT2 -5/6 62.0 63.9 -3.0 -1.1 It can be seen from the table that all of the outdoor ground floor receptors are predicted to be below the daytime noise standard. Levels at the upper floors upper floor levels are generally several dBA above the daytime standard but are not intended for outdoor uses. With appropriate home construction required for compliance with the nighttime standard (see discussion in Section 3.2, the applicable L10 standard will be 70 dBA, so that these homes will be in compliance with the state noise standards. David Braslau Associates, Inc. Page 7 Camden Ridge Traffic Noise Assessment Sound levels have also been estimated for the 6 -7 AM period assuming 60% of the PM peak traffic which is a typical value for this important commuting hour. These levels are presented in Table 3.2. The last column shows the predicted LIO level relative to the nighttime standard of 55 dBA. All levels are expressed in dBA (A- weighted decibels). Table 3.2 Predicted L10 for the 6 -7 AM Hour It can be seen that the predicted 6-7 AM L101evels exceed the nighttime level by as much as 12 dBA on the upper floor. However, exceptions to the Minnesota rules permit a higher L10 standard or limit to be applied if the land use meets certain conditions. These are addressed below in Section 3.2. Braslau Associates, Inc. L10 6- 7 AM Re Night Standard Receptor Ground Fir Upper Fir Ground Fir Upper Fir LOTi -3 61 62 6 7 LOT1 -4 62 64 7 9 LOTt -5 61 67 6 12 LOT2 -15/16 61 66 6 11 LOT2 -13/14 1 61 66 6 11 LOT2 -11/12 61 65 6 1 10 LOT2 -9/10 60 64 5 9 LOT2 -7/8 59 64 4 9 LOT2 -5/6 60 62 5 7 It can be seen that the predicted 6-7 AM L101evels exceed the nighttime level by as much as 12 dBA on the upper floor. However, exceptions to the Minnesota rules permit a higher L10 standard or limit to be applied if the land use meets certain conditions. These are addressed below in Section 3.2. Braslau Associates, Inc. Camden Ridge Traffic Noise Assessment 3.2. Compliance with State Standards for the 6 -7 AM (nighttime) Period Under exceptions contained in Minnesota Rules, commercial noise standards (NAC -2) can be applied to a residential land use if provisions in the rules can be met. The applicable provisions of Minnesota Rule 7030.0050 are presented below. Subp. 3. Exceptions. The noise area classification for a land use may be changed in the following ways if the applicable conditions are met. B. The standards for a building in a noise area classification 2 shall be applied to a building in a noise area classification 1 if the following conditions are met: (1) the building is constructed in such a way that the exterior to interior sound level attenuation is at least 30 dB(A); (2) the building has year-round climate control; and (3) the building has no areas or accommodations that are intended for outdoor activities. Since there are no areas outside of the upper floor that are specifically intended for outdoor use during the nighttime period, condition (3) of the provisions can be met. Condition (2) will be met if the homes are required to provide year-round climate control which is planned. Condition (1) can be met if the exterior to interior sound attenuation of the homes is 30 dBA or greater, Under NAC -2, the L10 is 70 dBA for both daytime and nighttime periods. Comparisons of the projected nighttime (6 -7 am) L10 levels for receptors relative to the NAC -2 L10 70 dBA standard are presented in Table 3.3. Braslau Associates, Inc. Page 9 Camden Ride Traffic Noise Assessment Table 3.3 6 -7 AM Level s relative to the NAC -2 Standards It can be seen that the Upper Floor daytime levels will be 3 dBA or more below the L10 70 dBA standard. Therefore, all of the homes on the site will comply with the state noise standards if the homes meet or exceed an exterior to interior noise reduction of 30 dBA. 3.3. Construction needed to provide an Exterior- Interior Noise Reduction of 30 dBA Proposed construction for the homes in the development is noted below: Exterior construction proposed: LP Smart Board 15/32' sheathing Tyvek wrap 2x6 studs 16 " o.c. R -19 batt insulation '/2" gypsum board Mechanical ventilation system: 3 -ton central air unit Windows STC 25 -28 Patio doors: STC 25 -28 Entry doors: STC 29 In order to achieve the 30 dBA exterior to interior sound attenuation, STC 28 windows would be required if windows make up 15% of the wall area, and STC 29 windows if windows account for 20% of the wall area facing the highway. David Braslau Associates, Inc. Page 10 L10 6- 7 AM Re L10 70 Receptor Ground 2nd Floor Ground 2nd Floor LOT1 -3 61 62 -9 -8 LOT1 -4 62 64 -8 -6 LOT1 -5 61 67 -9 -3 LOT2 -15/16 61 66 -9 -4 LOT2 -13/14 1 61 66 1 -9 -4 LOT2 -11/12 61 65 -9 -5 LOT2 -9/10 60 64 -10 -6 LOT2 -7/8 59 64 -11 1 6 LOT2 -5/6 60 62 -10 8 It can be seen that the Upper Floor daytime levels will be 3 dBA or more below the L10 70 dBA standard. Therefore, all of the homes on the site will comply with the state noise standards if the homes meet or exceed an exterior to interior noise reduction of 30 dBA. 3.3. Construction needed to provide an Exterior- Interior Noise Reduction of 30 dBA Proposed construction for the homes in the development is noted below: Exterior construction proposed: LP Smart Board 15/32' sheathing Tyvek wrap 2x6 studs 16 " o.c. R -19 batt insulation '/2" gypsum board Mechanical ventilation system: 3 -ton central air unit Windows STC 25 -28 Patio doors: STC 25 -28 Entry doors: STC 29 In order to achieve the 30 dBA exterior to interior sound attenuation, STC 28 windows would be required if windows make up 15% of the wall area, and STC 29 windows if windows account for 20% of the wall area facing the highway. David Braslau Associates, Inc. Page 10 Camden Ridge Traffic Noise Assessment 4.0 SUMMARY OF FINDINGS Traffic noise levels have been predicted for the Camden Ridge residential development northwest of TH 212 in Chanhassen, Minnesota. The analysis has been performed for nine receptor locations (representing 15 proposed living units closest to TH 212) both at the ground floor and upper floor level. An 8 -foot noise wall on top of a berm up to feet in height is proposed along the entire frontage of the development with TH 212. With the berm and wall combination, all of the ground level receptors are predicted to be below the daytime L10 65 dBA standard for residential land uses. Upper story receptors will experience levels several dBA above the daytime standard but are not planned for outdoor uses. Nighttime (6 -7 am) levels at all of the receptor sites are estimated to be over the L10 55 dBA standard. However, exceptions to the noise standards permit the NAC -2 or Commercial Noise Standard to be applied which is L10 70 dBA, providing certain conditions are met. With appropriate home construction, these conditions should be met so that all receptor sites will be in compliance with the state noise standards. y. \jobs\2013jobs\21 3038\mport\camden_ridge— traffic— noise— assessmencdw Braslau Associates, Inc. Page 11