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HomeMy WebLinkAbout2017-05-22 PACKET 07.5.STAFF REPORT CASE: C2017-017 ITEM: 7.5 PUBLIC MEETING DATE: 5/22/17 TENTATIVE COUNCIL REVIEW DATE: 6/21/17 APPLICATION APPLICANT: The Bancor Group, Inc. REQUEST: A concept plan review for a proposed single-family residential development with 139 home sites on 65 acres of land. SITE DATA LOCATION: North of 65th Street, South of Woodbury border, East of Hadley Avenue, West of Silverwood development (Hearthstone Avenue) ZONING: . R-2, Residential Estate GUIDED LAND USE: Low Density Residential and Parks/Private Open Space LAND USE OF ADJACENT PROPERTIES: CURRENT GUIDED NORTH: Woodbury Woodbury EAST: Residential Low Density Res. SOUTH: Rural Residential Low Density Res. WEST: Rural Residential Rural Residential SIZE: 65 acres DENSITY: 2.1 units per acre RECOMMENDATION Approval, subject to the conditions stipulated in this staff report. Cottage COTTAGE GROVE PLANNING DIVISION p_ � Grove fere Pride and Prosperity Meet Planning Staff Contact: John M. Burbank, Senior Planner; 651-458-2825; Iburbank(a)_cottage-grove. org Application Accepted:. 5/1/17 60 -Day Review Deadline: 6/30/17 City of Cottage Grove Planning Division a 12800 Ravine Parkway South • Cottage Grove, MN 55016 Planning Staff Report Amundson Property Concept Plan Review — Bancor Case No. C2017-017 May 22, 2017 Proposal Bancor Group has submitted a concept plan for a residential development in the northwest area of Cottage Grove known as the West Draw Development District. The concept sketch proposes the phased platting of 139 lots for detached single-family homes on three parcels of land totaling 64.7acres. This is in addition to the existing homestead parcel at 6055 Hadley Avenue, which will be incorporated into the plat. Parcel Identification Map The location is simply described as lying east of Hadley Avenue, west of the Silverwood develop- ment, north of 65th Street, and south of the Woodbury/Cottage Grove border. The property is cur- rently owned by William Amundson. HIGHLAND H,LL: Ol1RRIDOR PL 3 W A _clarsYs a' z IOL "E SITE B f „z FILLS jtOMEN I J 74 e3 rH Si Location Map Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 2 of 16 The Planning Commission is requested to review the concept plan and provide feedback to the applicant and City staff. After receiving feedback from the Commission on the concept plan, the developer will apply for a zoning amendment, planned development overlay (PDO), preliminary plat, and final plat. g �nolAnre.� 1 WOODB)JRY �v „,tea a C uncelA for i Amundson Parcels „ r {< 3 ses 4Ca ,ur.Etn°s naves R� b 6G7csnsr w� Z <ctl,sra Neighborhood Conformance Detail Map Concept Plan Background With this concept plan application, the applicant is proposing that the proposed subdivision be designed with the general standards of the R-4, Low Density Residential Zoning District with a Planned Development Overlay (PDO). This allows for variations to the R-4 development stand- ards and general guidelines, and creates design flexibility when laying out lots, streets, buffer areas, parks, and trails. This zoning approach was utilized in the last few residential subdivisions that the City approved. 10' I1 \�\ 6 7\`2 � 3 J-/�fx 17 24- 3' _L.. L21__I '� 1 --- ;` j ` r2 Osfi `I ; 13 1,1 2 3 J 6 � 9 i ii3 Is IJ // /^ \ I t - .7- i 1 12 -- .___ I g 't 17 I—n to - 6 7' 2 z v! s 11 1s I—e 11 3�J 2 3 J S 6 7 '_06 — to :'Il 12 i t 2 3 J 5 open Spate —25.8.1— Ja' lots - 25 Ponds—esti4-7aaes Amundson Concept Plan 55'lats-37 Amundson Nome Ponzl —1.5 cares prepared by JR N!!1 for the Bancor Group fic. 65' lass " J9 Regional TmIl 75' lots . 27 In .—I Pathways 4-28-2017 Total -138 Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 3 of 16 Review Schedule Application Received: April 26, 2017 Acceptance of Completed Application: May 1, 2017 Planning Commission: May 22, 2017 Tentative City Council Date: June 21, 2017 60 -Day Review Deadline: June 30, 2017 Neighborhood Meeting The applicant held a neighborhood meeting on May 16, 2017, which was attended by over a dozen people who expressed concerns about lot sizes, proximity of development, buffering, stormwater management, and traffic increases. Planning Considerations The following sections summarize the components of the concept plan as it relates to existing zoning ordinance performance standards, the City's Future Vision 2030 Comprehensive Plan, and other adopted plans. Property Characteristics The 64 -acre site has a combination of geographic features including a single family residence, two pine plantations, natural woodlands, steep hills and ravines, fallow agricultural fields, and an intermittent stream. An aerial photo of the property with contours and elevation points is shown below. 9go i ' _ a' Awl 930 E 920 900 � 940 t 910 900 910 1 C 940 _ 940 - 920 i 930 J 940 11 92b 910 930 930 930 :900 .890 920 t 900 910 920 930 3 ` 910 920 920. 910 940 910 E ?Iri. 900 900 910 930 tl, 890 920. 890 910 440. 920 910 930 900 900 930 890 930 890 890 900, 910 920 890 920 ' Aerial Photo Planning District This property lies within the West Draw portion of the community. For this project, the guiding land use document is the Future Vision 2030 Comprehensive Plan. Staff looked at the guiding Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 4 of 16 principles of the West Draw and East Ravine Master Plans for direction on community growth and development visions that could be applied to this proposed development. Land Use There are two land use classifications over the proposed site. The majority land use is Low Den- sity Residential and the balance is Parks and Private Open Space. The proposed residential por- tions of the concept plan are in conformance with the future land use plan, and the parks and open space portion is significantly in conformance and meets the intent of the plan. The parks section of this report will cover that compliance in more detail. The land use map below identifies the site and the two land use areas. Land Use Detail Zoning The property is currently zoned R-2, Residential Estate, which has a minimum lot size of 1.5 units per acre. The requested R-4, Single Family Residential, and PDO, Planned Development Over- lay, classifications are compatible with the adopted land use for the site. The minimum lot size in the R-4 zoning district is 7,500 square feet. The concept plan has an average lot size of 8,500 square feet. The average lot area of the adjacent lots in the Silverwood development that abuts the project is 15,582 square feet. Zoning — Planned Development Overlay (PDO) Plan Procedure The Planned Development Overlay (PDO) is a tool that permits and encourages flexibility of site planning with appropriate safeguards and controls. The PDO does not repeal the underlying zon- ing classification of the property, but provides some variation to the underlying requirements only if the result of the variation is equal or superior to the results achieved with the underlying zoning standards. Direction from the Planning Commission and City Council assists developers in modi- fying their development plan before filing planning applications for formal review and action. This will also provide the developer an opportunity to prepare responses to design alternatives and to document the benefits of incorporating flexibility from zoning standards. It is the applicant's responsibility to demonstrate that the proposed PDO accomplishes one or more of the following: A. Introduce flexibility of site design and architecture for the conservation of land, natural features, and open space through clustering of structures, facilities, amenities, and activities for public benefit; egend CG Cdf Bandar/ RM–CRIES II W CG Major Roads \ 301and u". all / •.110111.1 ul.W Q LAND USE A4lvlatal r Rural R.sYnhal i,,,, w Low Oensrtr R"dertol UN Denvt) Res J,r baj `Hg110enst/Resid.nba1 Q Liked Use - 00-nerdal - ommalT—b gMa C d.l. 65TH ST C R --7I ( ) P.1,SV Pakst'rNate Open Spa op �� God Couru i -' Ia65WOM RNY Land Use Detail Zoning The property is currently zoned R-2, Residential Estate, which has a minimum lot size of 1.5 units per acre. The requested R-4, Single Family Residential, and PDO, Planned Development Over- lay, classifications are compatible with the adopted land use for the site. The minimum lot size in the R-4 zoning district is 7,500 square feet. The concept plan has an average lot size of 8,500 square feet. The average lot area of the adjacent lots in the Silverwood development that abuts the project is 15,582 square feet. Zoning — Planned Development Overlay (PDO) Plan Procedure The Planned Development Overlay (PDO) is a tool that permits and encourages flexibility of site planning with appropriate safeguards and controls. The PDO does not repeal the underlying zon- ing classification of the property, but provides some variation to the underlying requirements only if the result of the variation is equal or superior to the results achieved with the underlying zoning standards. Direction from the Planning Commission and City Council assists developers in modi- fying their development plan before filing planning applications for formal review and action. This will also provide the developer an opportunity to prepare responses to design alternatives and to document the benefits of incorporating flexibility from zoning standards. It is the applicant's responsibility to demonstrate that the proposed PDO accomplishes one or more of the following: A. Introduce flexibility of site design and architecture for the conservation of land, natural features, and open space through clustering of structures, facilities, amenities, and activities for public benefit; Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 5 of 16 B. Improve the efficiency of public streets and utilities through a more efficient and effec- tive use of land, open space, and public facilities through assembly and development of land in larger parcels; C. Provide mixed land use and land use transitions in keeping with the character of adja- cent land uses in harmony with the comprehensive plan and the underlying zoning districts; and D. Provide for the clustering of land parcels for development as an integrated, coordinated unit as opposed to a parcel by parcel, piecemeal approach and to maintain these par- cels by central management including integrated and joint use of parking, maintenance of open space and similar features, and harmonious selection and efficient distribution of uses. The findings ultimately necessary for City approval must include, but not be limited, to the fol- lowing: A. The PDO plan is consistent with the intent of the PDO requirements specified in the City Codes. B. The PDO plan meets the standards required for a conditional use. C. Each stage of the PDO plan can exist as an independent unit. D. The area surrounding the PDO plan can be planned and developed in coordination and substantial compatibility with the proposed PDO plan. E. Any density bonus is consistent with the density bonus criteria of the PDO ordinance. F. Any variation of flexibility from zoning standards most similar in function to the pro- posed PDO plan must produce results equal to or better than those achieved by the applicable zoning standard. G. Other factors related to the project as the Planning Commission and City Council deem relevant. The Planning Commission and City Council may attach such conditions to their actions as they determine necessary to accomplish the purposes of this section. Approval of the concept plan would result in the final plans for the project being created under the proposed PDO performance standards. Zoning — Lot Width To allow for flexibility in meeting housing market demands, there has been a growing trend of De- velopers requesting concept and platting approvals for subdivisions with an assortment of lot width dimensions within the site design. This project is no exception with a concept plan that includes a lot width mix as detailed below: DEVELOPERS. Lot Width in Feet OPTION Quantity 40 25 55 37 65 49 75 27 Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 6 of 16 The average lot width of the adjacent lots in the Silverwood Development that abut the project is 85 feet. The smallest lot size width that the City has approved in the most recent past has been 55 feet with the Villas of Hidden Valley project. The applicant's rationale for the 40 -foot lot width request is covered in the Amundson Concept Narrative, which is attached. The basic premise is that the R-4 zoning district allows for attached housing, which has a zero lot line and lots similar in size to the requested smaller lots with the concept. The smaller lot size also maintains lot counts while minimizing land consumption, which in turn can assist with increasing tree preservation areas. The narrative packet includes a detail on layout options for the design of Block 10 that includes the proposed 40 -foot wide lots. Option 1 40' Wide Single Family Lots Option 2 55' Wide Single Family Lots /18 I I If 25 1 1 24 I 2 23 I 22 { —I 3 I 4 21 I I 20 I I I 7 19 ((o) 18 4 15 I I g 17 I I 9 16 I I 1 1 t0 15 I I I JI „ 14 , I . Block 10-40' Lots 25 units Total Units 138 units Overall Gross Density 2.13 units/ac Option 2 55' Wide Single Family Lots Option 3 Townhome (TH) Lots t � l �l 1 ! 1 '2I _J 15 _ � { I 6 27 ' I I - -� I -7 2 1 '23� I I I 0 zz I I 1,1 1.1 {. 1 6' 18� ( �- 17.� ) j I� Block 10—TH Lots 33 units Total Units 146 units Overall Gross Density 2.26 units/ac Small Lot Platting Option Details 40 -Foot Lot Example — Blaine /18 I I If I- 2 17 I �J ,6 I 3 I Ii 4 15 I - I I 5 13 I I 6 ( . j 12 I I 8 „ I J` Block 10-5S' lots 18 units Total Units 131 units Overall Gross Density 2.03 units/ac Option 3 Townhome (TH) Lots t � l �l 1 ! 1 '2I _J 15 _ � { I 6 27 ' I I - -� I -7 2 1 '23� I I I 0 zz I I 1,1 1.1 {. 1 6' 18� ( �- 17.� ) j I� Block 10—TH Lots 33 units Total Units 146 units Overall Gross Density 2.26 units/ac Small Lot Platting Option Details 40 -Foot Lot Example — Blaine Planning Staff Report —Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 7 of 16 Lot Standards and Setbacks The table below identifies the proposed lot setback standards: Table 4 Lot Widths at setback Front Set -Backs Rear Side Lot Size Avg ** Hardcover 40' Lots 25' 25' 5' 4,800 65% 55' Lots 25' 25' 5'& 10' * 61,600 60% 65' Lots 25' 25' 5'& 10' * 7,800 60% 75' Lots 25' 25' 5' & 10' * 9,000 60% * 7.5' would also be allowed so long as there is 15' between homes **Lot size minimum within 200 sq. ft. of avg. — lot depths average 120' The Applicant's concept narrative also included a graphic of the proposed lot standards: 40' 55' 65' 75' 25' 25' 25' 25' 5 30'x 70' 5 10' 40',x 70' 5 10' 50'x 70' 5 10' 60'x 70' S 120' 25' 25' 25' 25' As an alternate to 5' and 10' side yard 75' can be used so long so there is 15' between structures Staff has informed the applicant that the requested 40 -foot lot widths are below the design threshold that is acceptable in the community. The applicant was understanding of the comments, but wanted to present the concept in the public forum especially when considering the design challenges of the trees and steep slopes on the site. Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 8 of 16 Zoning — Standards Comparison The following table shows a comparison of the proposed R-4, Low Density Residential zoning dis- trict, and the developer's proposed Planned Development Overlay (PDO) requests: The proposed development standards as highlighted above will be the foundation in determining the unit base count for the site. The PDO is intended to promote creativity and land use efficien- cies that will still be compatible with the future land uses in terms of need, convenience, and service. Zoning — Density The developer's concept sketch proposes a density of 2.1 dwelling units per acre for the platted lot areas. Subtracting the ponding/wetlands and major road right-of-way during the review of a final product would increase the density slightly. The density range for a low density residential land use designation is one to four dwelling units per acre. The regional goal for net density of this land use designation is three units or greater per acre, while the West Draw Master Plan density goal was 2 units per acre. Environmental Assessment Worksheet (EAK9 The proposed project is below the lot count threshold that would trigger an environmental review prior to development. Transportation — Major Road Right-of-Ways/Access The western access to the property is off of Hadley Avenue, which is identified as a major collec- tor in the Comprehensive Plan. Right-of-way will be required to be dedicated with any platting of the property. Transportation — Local Roads The proposed local roads are consistent with the City's current design standard with a road width of 28 feet face -of -curb to face -of -curb. The concept plan also includes interconnections to adja- cent properties. Consistent with City policy, temporary turn-arounds are recommended to be de- signed and constructed at the dead -ended streets on the site. The permanent cul-de-sacs shall be designed per standard City detail plate. Current R-4 Standards Proposed PDO Minimum lot area 7,500 sq. ft. minimum 8,500 sq. ft. avg. based on gross land area Minimum lot width 75 feet 40 to75 feet 10 feet (house side) 5 and 10 feet Minimum side yard setbacks 5 feet (attached garage side) 7.5 feet Minimum front yard setback 30 feet 25 feet Minimum rear yard setback 35 feet 25 feet Requested lot width plus 10 Corner lot width 85 feet feet Minimum side yard setback 20 feet 20 feet on a corner lot The proposed development standards as highlighted above will be the foundation in determining the unit base count for the site. The PDO is intended to promote creativity and land use efficien- cies that will still be compatible with the future land uses in terms of need, convenience, and service. Zoning — Density The developer's concept sketch proposes a density of 2.1 dwelling units per acre for the platted lot areas. Subtracting the ponding/wetlands and major road right-of-way during the review of a final product would increase the density slightly. The density range for a low density residential land use designation is one to four dwelling units per acre. The regional goal for net density of this land use designation is three units or greater per acre, while the West Draw Master Plan density goal was 2 units per acre. Environmental Assessment Worksheet (EAK9 The proposed project is below the lot count threshold that would trigger an environmental review prior to development. Transportation — Major Road Right-of-Ways/Access The western access to the property is off of Hadley Avenue, which is identified as a major collec- tor in the Comprehensive Plan. Right-of-way will be required to be dedicated with any platting of the property. Transportation — Local Roads The proposed local roads are consistent with the City's current design standard with a road width of 28 feet face -of -curb to face -of -curb. The concept plan also includes interconnections to adja- cent properties. Consistent with City policy, temporary turn-arounds are recommended to be de- signed and constructed at the dead -ended streets on the site. The permanent cul-de-sacs shall be designed per standard City detail plate. Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 9 of 16 The concept plan details landscaped islands in cul-de-sacs. The islands are recommended to be platted as outlots that the homeowners association must own and maintain. The islands shall have irrigation provided to them. Sidewalks The concept plan identifies sidewalks consistent with City design standards, which is a sidewalk on one side of local roads. Cul-de-sacs are excluded from the sidewalk requirement. The City's preferred locations of the sidewalks for the project are identified in red in the detail below. I \ 2�3)� 1 9 5 8 7 0 2 3 \ I i 3 / � .—� 1) II 4 \ 3 g 2 17 � 1 Cts 9 2 ' 15 10 3.. .. 11 4 1 14 12> / 3 40 � e , 13 1315 � 17�/ 9 18 ; 319' 1 20 I � 2 3 i 5 6 7 12 13 2 t 2`3 4 7 0 5 �\ 10 11 19 I ' 9 10 1 a 3 - Sidewalk Detail • 25 1 24 16 p — 23 15 3_ '-2 14 F 6 20 I 13 I 8 �� 18 I i2 s ,7 _' 11 r g —f!74_I 10 I 11 t4 12 13 118 2 3 , 4 5 /1 Trails Consistent with the Comprehensive Plan, the concept plan identifies an east -west recreational trail in the planned park dedication area. As a component of the PDO, the developer will be re- quired to finance the installation of the natural trails within the project, the bituminous recreation trail within the project, and the bituminous transportation trail adjacent to Hadley Avenue. The bituminous transportation trail along Hadley would be installed as a component of the instal- lation of public utilities when Hadley Avenue is reconstructed. The trails in the project will connect with existing or planned transportation and recreation trails identified in the Comprehensive Plan. Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 10 of 16 r L' 1 5 6 / 13 8 3 r 3 4 0 to ,1 \NATURE TRAIL 17i 1 (11 19 19 a \ ' 2 1 `1 -1s - TRANSPORTATION TRAIL 9 15 _ 1 10 1t l , 14 12 13 41 ` % b 73 15 14 ��\ 1 - -_7 f 1 12. / 17 10 19 8 / "- 20, 1 2 0 4 5 .. 6 7 6 /` 10 11 12 RECREATION TRAIL ��...i... Trails Detail Buffered Landscape Area The City requires landscaped buffers along all major roadways within the community. The con- cept plan does not have any lots abutting Hadley Avenue, so the existing natural wooded area would be considered to meet the buffering requirements. This area should be included in the forest restoration plan. Fencing No fencing is proposed as a component of the concept plan, but a requirement of a PDO ap- proval would be that any fencing in the subdivision would need to meet the HOA requirements. Wetlands The wetland inventory was completed for the site as a part of a previous development attempt, which identified wetlands in the project area. This report has expired and would be required to be updated and submitted to the South Washington Watershed District (SWWD). Public Open Space The City's Park Master Plan for this area identifies a future parks and private open space land use and a public trailway corridor that threads through the southern portion of the project area from east to west across the middle of the site. C- Park Plan Detail 17 25 24 Is 113 3 4 22 I 21 14 20. -) IV 12 7 lob I-- -_ 9 I— —)_ 1B _17 16 11 -_ IO p I 10 11 4 . L �Z-_3 1 a 7 8 Buffered Landscape Area The City requires landscaped buffers along all major roadways within the community. The con- cept plan does not have any lots abutting Hadley Avenue, so the existing natural wooded area would be considered to meet the buffering requirements. This area should be included in the forest restoration plan. Fencing No fencing is proposed as a component of the concept plan, but a requirement of a PDO ap- proval would be that any fencing in the subdivision would need to meet the HOA requirements. Wetlands The wetland inventory was completed for the site as a part of a previous development attempt, which identified wetlands in the project area. This report has expired and would be required to be updated and submitted to the South Washington Watershed District (SWWD). Public Open Space The City's Park Master Plan for this area identifies a future parks and private open space land use and a public trailway corridor that threads through the southern portion of the project area from east to west across the middle of the site. C- Park Plan Detail Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 11 of 16 In addition to the trail corridor, the applicant's plan identifies the balance of the areas, identified in green below, as being dedicated to the public as a component of the subdivision and PDO, con- taining tree protection areas, steep slopes, wetlands, and ponding areas. Park Dedication Areas (Dark Green) Based on the gross acreage of the parcel, the City has the ability to require the dedication of 6.5 acres of land through the subdivision process. The areas identified for public dedication totals 25.8 acres. The City's current policy is to not give full 100 percent credit for lands dedicated that contain tree protection areas, steep slopes, wetlands, and ponding areas. Lands given in excess of the dedication credit formula will be considered one of the City's benefits for allowing site de- sign flexibility through the PDO process. The final dedication credit for this site has yet to be final- ized and will be presented with any future platting of the property. Utilities The City's public utilities are currently available adjacent to the eastern portion of the site, and will need to be routed north along Hadley Avenue to service the western half of the site. Based on previous land use decisions, this property is in the West Draw II Sanitary Sewer District, which has a higher rate structure than areas in the balance of the West Draw District. The Developer will be responsible for the cost of these utility and roadway improvements. The final utility design for the project shall include utility connections and easements as directed by the City Engineer. A memorandum from Stantec dated May 15, 2017, is attached and contains Engineering's comments on the concept plan. Stormwater Management No detailed stormwater design has been completed to date but the applicant has acknowledged that a final design will be coordinated through the South Washington Watershed District and the Cities of Cottage Grove and Woodbury. In an attempt to save additional trees, the applicant has requested that the stormwater management design process allow for creative flexibility in order to meet desired/required standards. The project is outside of the wellhead protection area. 2 \ 3 2 � 3 y1 /�\ B 10 - \NATURE TRAIL 11 > t0 t' 9 / I H \� 8,7\� t 17 181 `� 19 3 �I� ', 17 8 \ - 2�[ii\ 11 18- \` 20 / 1 I 25 24 1 18 TRANSPORTATION TRAIL 9 -\ 3 15 t 2 I 23 _ 15 10 5 3 20 14 13 3 4 L5- 1 13 2 3 4 �e- 18 12 13 74 '.�/ /� I - "7 ' 12 7 i- 8 _ Is 17 I 11 17 I?J2 5 1 1 i -1._ 4 18 3 10 L--� ` 19 t 7 20 2 3 4 5 8 7 t� 70 / �. 11 ' \ �. r r — ♦ s / .10_ RECREATION TRAIL 000 % Park Dedication Areas (Dark Green) Based on the gross acreage of the parcel, the City has the ability to require the dedication of 6.5 acres of land through the subdivision process. The areas identified for public dedication totals 25.8 acres. The City's current policy is to not give full 100 percent credit for lands dedicated that contain tree protection areas, steep slopes, wetlands, and ponding areas. Lands given in excess of the dedication credit formula will be considered one of the City's benefits for allowing site de- sign flexibility through the PDO process. The final dedication credit for this site has yet to be final- ized and will be presented with any future platting of the property. Utilities The City's public utilities are currently available adjacent to the eastern portion of the site, and will need to be routed north along Hadley Avenue to service the western half of the site. Based on previous land use decisions, this property is in the West Draw II Sanitary Sewer District, which has a higher rate structure than areas in the balance of the West Draw District. The Developer will be responsible for the cost of these utility and roadway improvements. The final utility design for the project shall include utility connections and easements as directed by the City Engineer. A memorandum from Stantec dated May 15, 2017, is attached and contains Engineering's comments on the concept plan. Stormwater Management No detailed stormwater design has been completed to date but the applicant has acknowledged that a final design will be coordinated through the South Washington Watershed District and the Cities of Cottage Grove and Woodbury. In an attempt to save additional trees, the applicant has requested that the stormwater management design process allow for creative flexibility in order to meet desired/required standards. The project is outside of the wellhead protection area. Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 12 of 16 Additional stormwater review will be required upon submittal of the final grading and utility plans for the site. Grading No formal grading plan has been submitted with the application. Based on the tree preservation areas, ponding requirements, and steep slopes, the final grading plan will require attention to de- tail and some creativity. Additional grading review will be required upon submittal of final grading and utility plans for the site. Tree Preservation As reported earlier, the site is heavily wooded and tree preservation planning will be a component of the development process. The information on the existing tree vegetation on the site is detailed below. 1. Existing Conditions Table 1 Existing Conditions - Land Cover Forest 39.1 Red Pine Plantation 7.6 White Pine Plantation 8.7 Former Croplands 8.5 Wetland 0.4 Hadley ROW 0.4 64.7 Approximate Area - Generally accurate but final area will be calculated with pre -plat application Site Analysis zoite uaiculauon uetan Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 13 of 16 The applicant has been working with staff on tree preservation and mitigation for awhile and has included a detailed narrative of a proposed tree preservation and mitigation plan in the concept narrative, which is attached. The ordinance allows for 40 percent removal before mitigation is required. 4 6 6 712 9 6 \ 4/ 3 \ _ 113 6 \�( 7\\ \2 ; 1 17 O\ ; 1 ` , 16 Ie 19 0 1 { \ �//q�; 1 20 9 = 16 J 101 �\ \ 12 3 / I4 / 15 /� /�� t6 / 17 / 2 2 t6 \ 3 16 2. Restoration Areas/Zones f O94 s Wrest 3 : Ravine/Greenway ■ l� stream 223 j _ 1 3 ' _u If Red Plne Plantation ` I 21 ' '� 20 Reforestation 3 4 I lIl 16 ' fifers Pond DO - / I� i , 2 3, 4 V 6; `` 3 7 12 9 1 1t 9 � � 10 -- / 9 1 2 3 a 6 6 7 B i= Restoration Plan 4-Z3-2017 – 6 10 tl f O94 s 3 : 17 26 2 1 24 I 1 t6 223 j _ 1 3 ' _u If I 16 11 ` I 21 ' '� 20 I 13 3 4 I lIl 16 ' L 9 17 I I 11 9 - I6 I t0 I 7 610 IS 9 9 6 I- II 17 / ) 6U) 9 10 6 11 12 I i� 2 3 4 ReponJ7nfl ••••••••• Informal Pathways Staff is generally supportive of the draft plan and will continue to work with the applicant on final- izing it prior to any platting of the property. One component of the mitigation plan is to restore key areas of the preserved woodlands prior to dedication to the public. Architecture The concept narrative included sample elevation details of some existing small lot products simi- lar to the proposed product styles planned for this subdivision. Product examples that would fit on the larger lots was also included. Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 14 of 16 Garage The City ordinance requires a minimum garage size of 440 square feet. The models the applicant is proposing to market on the site would meet this criteria. Recommendation The Planning Commission is asked to provide direction to the applicant on the concept plan with respect to the adopted Comprehensive Plan, zoning development standards, lot widths, tree preservation, and the City's architectural guidelines, and to recommend to the City Council that the concept plan for the phased platting of 139 lots for detached single-family homes on three par- cels of land totaling 64.7 acres be approved as a planned development overlay, subject to the condi- tions below: 1. The property is rezoned to R-4, Low Density Residential, with a Planned Development Overlay, prior to any platting. 2. The preliminary plat design shall only include a mix of lots ranging from a minimum lot size of 55 feet wide up to 75 feet wide. 3. The water utility plan shall conform to the city's water supply and distribution plan. 4. The sanitary sewer utility plan shall conform to the city's sanitary sewer comprehensive plan. 5. All stormwater designs shall conform to the City's Surface Water Management Plan. 6. The utility plan for the project shall include utility connections and easements to adjacent properties where identified on City master utility plans. 7. The Developer is responsible to provide for the necessary easements and costs associ- ated with road and utility improvements serving the site. 8. A final tree preservation and mitigation plan shall be submitted with the plat of the property. Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 15 of 16 9. The preliminary plat design shall identify all park, open space, and trail corridor areas to be dedicated to the public as a component of the Planned Development Overlay. 10. The preliminary plat and associated site plan shall include the design and installation of nature trails, eight -foot wide bituminous transportation trails, and recreation trails as identi- fied in this report and as depicted on the concept plan. 11. All ponding areas associated with the preliminary plat shall be platted as outlots and dedi- cated to the City. 12. Temporary turn-arounds shall be designed on all dead -ended street connections to adja- cent properties. 13. The preliminary plat application shall include the proposal to create a private homeowners association for the subdivision. 14. Landscaped islands shall be provided in the center of all cul-de-sacs and have irrigation installed to the islands. The islands shall be platted as outlots. The homeowners associa- tion must own and maintain these outlots. 15. A six-foot wide sidewalk shall be constructed on one side of all local roadways within the subdivision, except in cul-de-sacs. 16. The minimum front yard setback for the principal structure must not be less than 25 feet. 17. Garage setback shall not be greater than six feet in front of the porch or living area. 18. The minimum finished floor area for a single-family rambler is 1,500 square feet. For two- story/modified and multi-level/splits, the minimum is 2,000 square feet above grade finished floor area. 19. The minimum attached garage area shall be 440 square feet. 20. For properties with a principal structure facing a public roadway, four-sided architectural design is required on all sides of the structure. 21. The duplication of house styles with adjacent property house styles and colors shall be prohibited in the final site design criteria. 22. On Villa housing products, a minimum of 70 square feet of the front facade shall be covered by brick or stone. 23. On two-story housing products, a minimum of 100 square feet of the front fagade shall be covered by brick, stone, stucco, or equivalent product approved by the Community Devel- opment staff. 24. The front fagade siding shall consist of LP siding, cemetious board, or equivalent product approved by the Community Development staff. Vinyl siding is prohibited. Planning Staff Report — Case No. C2017-017 Amundson Property Concept Plan — Bancor May 22, 2017 Page 16 of 16 25. Garage setback shall not be greater than six feet in front of the porch or living area. 26. The minimum front yard setback for the principal structure must not be less than 25 feet. 27. The side yard setback for the principal structure must not be less than 7.5 feet 28. The principal structures shall utilize a combination of roof pitches in the construction design. 29. A wetland delineation report shall be submitted with the preliminary plat application. Prepared by: John M. Burbank, AICP Senior Planner Attachments Amundson Concept Narrative Engineering Memorandum Dated 05/15/2017 Amundson Property Concept Narrative April 26, 2017 Bancor I. Introduction: We would like to thank you in advance for reviewing our development concept fort he Amundson property. We are excited about our concept and believe that we have an opportunity to create a great neighborhood within Cottage Grove. As you may know a number of development proposals have been reviewed by the City for this property. Due to the complexity of the site and its history we are starting with a concept plan review so we both have a chance for a more informal review prior to moving forward with a plat application. II. Bancor & Development Team: Our company, the Bancor Group, has been developing property in the Twin Cities for over 20 years. We have completed both large and small development projects. Previous projects have included Bailey's Arbor and Woodhaven in Woodbury, Amundson Place in Stillwater, Wild Meadows in Medina, Woodland Cove in Minnetrista and Locust Hills in Wayzata to name a few. Bancor communities have received a number of environmental awards and recognitions. These have included but are not limited to the Bennie Award from the Builders Association for excellence in neighborhood design and construction for Woodland Cove, Watershed Heroes Awards from the Minnehaha Creek Watershed District for Locust Hills & Woodland Cove. In additional to awards we have spoken to several conferences and professional organizations on a number of development topics including low impact development and have given tours of our projects to numerous organizations. Our concept development team includes: • Paul Robinson, Land Development Manager, VP Bancor Group • Dave Newman, Owner/President, Bancor Group • Kurt Quaintance, Planner/Engineer, JR Hill Engineering • Marcus Hampton, Surveyor, VP, JR Hill Engineering • Kim Chapman — Ecological Consultant, Applied Ecological Services • Gary Renneke — Legal, Larkin Hoffman III. Property Owner: • Bill Amundson, 6055 Hadley Avenue S., Cottage Grove. IV. Property: Our concept plan includes the development of three properties, these are identified by the following Washington County Parcel ID (PID) numbers. Parcel A - 0502721220003 — 6.93 Acres Parcel B - 0502721220001— 23.71 Acres Parcel C - 0502721210001— 34.06 Acres Total Acres — 64.7 Acres Figure 1 1. Existing Conditions Toble 1 Existing Conditions - Land Cover Forest 39.1 Red Pine Plantation 7.6 White Pine Plantation 8.7 Former Croplands 8.5 Wetland 0.4 Hadley ROW 0.4 64.7 * Approximate Area - Generally accurate but final area will be calculated with pre -plat application This property is heavily wooded and has a significant amount of topographical change (Figure 1). Figure 2 provides a depiction of the Table 1 above and Figure 3 provides additional information of the topography on the property. The existing tree cover and the meaningful change in topography are the two biggest challenges to developing this property. Topography - As shown in the Figure 3 the property starts with a high point along the northern property line at 986 and drops to a low point along Hadley Ave of 864 for a 122' of elevation change across the property. One can experience this in part by driving along the property on Hadley Ave. The property is also divided by a drainageway/ravine that extends north to south through the easternmost parcel. 3 A I C 1 940 910' 430 Sl 1. ,�,i-�[(w•z�,�eyl�K.1 1 _ 9A0 j .. 930 910 900 900 910r 940 �0 920 930 940 90 i �'- 910 930 930 930, 900 .- .890% ... + _ ,.y. 420 900 910 920 930 920 920. 910 910 900 910 936 970 940, 890 900 920 930 11 890910 940 '920 JI 410 0 900 900 930 890 9�0.. 890 910 920 y g90 900 920 Figure 4 2. Current Zoning and Guiding The property is currently guided in the Comprehensive Plan for Low Density Residential with an allowable density range of 1-4 units per acre. The property is currently zoned R-2 Residential Estate District. V. Development Proposal: The development concept that we are submitting for review, builds in part on the work done by previous developers but also takes a fresh look at the property. We worked hard to incorporate homesites into the plan, while at the same time working with the topography and minimizing grading impacts, saving significant areas of the forest, creating meaningful open spaces and trail connections, allocating enough area for storm water treatment and finally enough homesites to make the project successful. As with most developments we are trying to balance these many interests to create a development plan that not only looks good and works but one that will also be financially successful. To accomplish this, we are asking for a Planned Development Overlay District (PDO) and a rezoning to R- 4 as the underlying district. r 1 7 \3 9 5 8 7; 8 4 2 3 \� \� 21, 3 %—�10.1, 12 3 13 71 18 20 -8 \\ \\ 2 _ l 165 1 _ 4 10 \ \( 3. 1 11 \ ` j� �.�, 1 14 \\ 1 /3 4055 / 2 e 1 20 \ 1 1514 '\ 1 7t, 1 12_ 11,_ 17 2) 2 19 \ 3 l / 9 ,0 19 8 20 _ 1 2 3 4 5 7 j Open Space -25.8 acres - , Ponds — est. 4 - 7 acres Amundson Concept Plan Amundson Home Parcel -1.5 acres Prepared by Hill for the BoncorGroup Inc Regional Trail Informal PatFnvays 4-28-2017 5 40' Lots - 25 55' Lots- 37 65' Lots- 49 75' Lots- 27 Total -138 10 11 8 9 3 74- 17 5 , tfi rfI 3 ..J ( 3 72 15 14 4 _21 �-- 1 2 —� i- 5 20 i 13 3 4( 4 7 11_0)18 I �12 11 - I 8 17 I L _ I- 9 16 _� i _ 10 7 �, 6 I 5 I 10 15 — 11 8 10 11 1 ,t i 2. 3 ; 5 40' Lots - 25 55' Lots- 37 65' Lots- 49 75' Lots- 27 Total -138 1. Highlights of Proposal and Rationale for Planned Development overlay District (PDO) There are a number of reasons for proceeding with a PDO. The rationale are described in detail throughout this narrative and summarized below. a. Clustering homesites to provide of 40% open space. b. Preserving hundreds of trees. c. Restoring the remaining forest areas by removing buckthorn and performing other restoration activities. d. Providing for a regional trail connection across the southern portion of the property linking our neighborhood and the Silverwood neighborhood to the Highland Hills Corridor. e. Preserving a significant greenway on each side of the ravine area and streambed. f. Restoring and enhancing impacted portions of the streambed and banks. g. Providing a variety of lifecycle housing choices. h. Utilizing creative design to work with the significant topography of the property and to save trees. I. Developing several existing parcels into one neighborhood, linking the yet to be developed properties from Silverwood to the east and to Hadley Ave S. to the west. 2. Areas* Table 2 Development Area Acres Amundson Home Parcel 1.5 2% Lotted Area 27.4 42% Open Space 25.8 40% Hadley Rd 0.4 1% Internal ROW 9.9 15% 64.7 100% *Based on concept plan. Exact acreages may vary once plan is entered into CAD. When reviewing how the area of the development site is allocated, you can see how significant the amount of open space is. Nearly 40% of the total site area has been allocated to Open Space with almost 70% of the homesites abutting open space. 3. Unit/Lot Types In order to save trees and provide a significant amount of open space we are proposing lots sizes and standards closer to what you would find in an R-4 district. We have split the homesites into the more traditional single family homesites and smaller lot homesites. There will be further information about homes for the smaller and other lot sizes later in this narrative. A Table 3 Lot/Product Types in Concept Lot Types # 40' Lots 25 18% 55' Lots 37 27% 65' Lots 49 36% 75' Lots 27 20% 138 100% 4. Density To reduce the overall development footprint, we are using, on average, homesites that are smaller. However, because of the significant amount of open space the overall density is much lower. The overall density of the property is only 2.1 units per acre which is closer to the densities found in an R-2.5 district. Density -138 units/65 acre = 2.13 units/acre S. Proposed Lot Standards Related to the theme of reducing the development footprint, lot standards have also been adjusted. Table 4 Lot Widths Set -Backs Lot Size Hardcover atsetback Front Rear Side Avg ** 40' Lots 25' 25' 5' 4,800 65% 55' Lots 25' 25' 5' & 10' * 6,600 60% 65' Lots 25' 25' 5' & 10' * 7,800 60% 75' Lots 25' 25' 5' & 10' * 9,000 60% * 7.5' would also be allowed so long as there is 15' between homes **Lot size minimum within 200 sq. ft. of avg. — lot depths average 120' Figure 5 40' 55' 65' 120' 25' 50'x 70' 25' 25' 60' x 70' 25' As an alternate to 5' and 10' side yard 75' can be used so long so there is 15' between structures 7 Based on our initial calculations we believe that that the overall average size of the lots in the development will be around 8,500 sq. ft. So while we are asking for flexibility on the specific lot sizes the overall average will still exceed the minimum lot size for the R-4 District. As mentioned above when reviewing the lot standards, it may appear that we are venturing far from the typical R-4 standards. However, we would ask that when you look at the smaller lots sizes you think about them in the context of a townhome, quad homes or twins home which are all allowed uses with an R-4 district. If you were to imagine for example Auburn woods in Cottage Grove where there are fourplex row units. The lots in Auburn Woods are 32' -36' wide, the homes are attached and distance between fourplexes is limited. Our proposed 40' lots would have 10' between units. Another example allowed in the R-4 district, is an 8 unit townhome, this too would have significantly higher densities and no set -back between units when compared to the 40' lots we are asking you to consider. Why we are proposing this is because builders and other customers have been asking us to accommodate this product option. In our opinion we believe the 40' lots actually meet the standards within the flexibility of the PDO. The 40' and 55' lots allow for tree savings, provide a product option that is currently being demanded by both millennials and retiring baby boomers, who want less yard, less maintenance, and option for single level living, and affordability. Below are three ways that block 10 could be developed. While all options are acceptable we prefer Option 1. Figure 6 Option 1 40' Wlda Single Family Lots Total Units 138 units Overall Gross Density 2.13 units/ac Option 2 55' Wide Single Family Lob r�y 16 I I I I 17 216 3 I I— I 14 I I 5 I 6 13 l I 1_—J 7 12 i I I� l ti 11 I I 25 r I 1 24 1 ( I 2 I 23 _�. J 3 22 I I _ I 4 21 i 18 units 5 zo I 131 units Overall Gross Density �j�n1 19 "� I'3 8 18 9 16 i I I 1015 „ 14 i i 13� Block 20— TH Lots 33 units Total Units 146 units Overall Gross Density 2.26 units/ac IF Block 10-40' Lots 25 units Total Units 138 units Overall Gross Density 2.13 units/ac Option 2 55' Wide Single Family Lob r�y 16 I I I I 17 216 Option 3 Townhome (TH) Lots 3 I I— I 14 I I 5 I 6 13 l I 1_—J 7 12 i I l ti 11 I I I g 10 ' t ----� r ---I--' I '17-25 I Ij n 0 I _ I 23.. I Block 10-55' Lots 18 units Total Units 131 units Overall Gross Density 2.03 units/ac Option 3 Townhome (TH) Lots I 'i yI I 1_—J _ I '17-25 I n 0 I _ I 23.. I 0 22 I I'3 I 18'� / Block 20— TH Lots 33 units Total Units 146 units Overall Gross Density 2.26 units/ac 6. Hardcover As a part of the PDO we are proposing that the hardcover standards for the individual lots be higher, providing that we stay below your hardcover requirements for the overall site. Once a preliminary plat is prepared we can set more exact standards, but if each of the lots maximized the hardcover based on the average lot size the overall development, 40% of the total site would have hardcover which is the amount allowed per site in the R-4 district code. It is our intent to keep the overall hardcover to 40% or less as calculated by taking the total site hardcover as shown below and dividing that by the total site area as shown in Table 5. Table 5 Hardcover Areas* Lot Area 16.16 Streets 7.50 Trails 1.00 Sidewalks 1.50 Total Hardcover 26.16 of Hardcover 40% *This is an example calculation to show that our intent is to not exceed 40% over the entire property. 6. Wetlands and Wetland Buffer A wetland inventory and delineation had been completed for a previous development proposal. That delineation was used when planning for in the current concept. Based on previous wetland delineation, the wetland on the property would likely be considered a manage 2 wetland and would therefore require a 25' buffer. We intend to provide 25' at minimum. If by chance a 50' buffer is required that can be accommodated with limited buffer averaging. In the current concept there is only one small area that would not meet a 50' requirement. In order to construct the roadway linking the western and eastern portions of the property there could be some impacts to this wetland. This will be worked out in subsequent submittals and will include an updated delineation. Trails may also be located in the wetland buffer areas as they are today. If located in the buffer areas additional buffer will be allocate to offset any impact. Also, to restore the streambed and create ponding the wetland and wetland buffer may be to be graded as a part of the development and restoration work and then seeded and restored once the grading and restoration work is completed. VI. Tree Preservation, Restoration & Trails: 1. Tree Preservation Forest is the dominate characteristic of the Amundson property today (see Table 6). To that end much of this narrative has talked about the need for smaller lots and other decisions made to protect a significant amount of the forested area. Nonetheless with development there will be impacts. Our plan will exceed the base amount of impact allowed in the ordinance without mitigation. As a part of the PDO we are asking for flexibility for how we mitigate the tree impacts. The tables below outline the likely tree impacts and our proposal for mitigation. The mitigation is further described in the restoration section of this narrative. Over the years, a significant amount of work was spend understanding and analyzing the trees on the property. As a part of this work two areas where trees were planted in rows for future harvesting were identified as plantations. To that end, the property owner applied for and was approved to harvest these two plantations areas per the harvest plan requirements in the City's tree preservation ordinance. These areas are included below in the total amount of land cover but are not a part of the forested area that would require mitigation. Table 6 Total Land Cover with Tree In order to update the previous work and to quantify the remaining natural forest area, a sample acre tree survey was completed in the middle of the forested area (Figures 8, 9). The outcome of this survey is shown and summarized below (Table 7). Based on this survey the total number of trees and characteristic of the types and sizes of trees was determined and then extrapolated over the 39.2 acres. Figure 7 IM Acres Red Pine Plantation 7.6 White Pine Plantation 8.7 Natural Forest 39.2 Total Tree Acres 55.5 In order to update the previous work and to quantify the remaining natural forest area, a sample acre tree survey was completed in the middle of the forested area (Figures 8, 9). The outcome of this survey is shown and summarized below (Table 7). Based on this survey the total number of trees and characteristic of the types and sizes of trees was determined and then extrapolated over the 39.2 acres. Figure 7 IM The survey basically found that per acre there are on average 87 trees of a countable size. Of the 87 trees, 66 trees are alive per acre. The trees that are alive fit into the following tree inventory and replacement categories see Tables 8 and 9 Tree Sample Area Figure 8 Figure 9 11 O,fto! �•0R11 , QttoL3 Q�ou:l 1 OI Q M]0 \ 1 ,M]i \. 01 0 0"47 e0115 i - 946— -- —\C \ Q�ta.n ,®1qN\ 11 Table 7 Acre Tree Sample -Amundson Dead Trees Tag # Elevation Type Size Size Status 100303 928.07 OAK 22 Hard DEAD 100312 928.67 OAK 9 Hard DEAD 100314 927.20 CHERRY 16 Hard DEAD 100315 925.86 OAK 23 Hard DEAD 100320 917.04 CHERRY 10 Hard DEAD 106482 911.40 BOXELDER 14 Soft DEAD 106485 911.55 ELM 13 Soft DEAD 106494 917.02 OAK 19 Hard STUMP 109958 914.74 OAK 30 Hard DEAD 109960 920.70 OAK 20 Hard DEAD 109961 921.91 OAK 20 Hard DEAD 109965 923.10 OAK 19 Hard DEAD 109972 920.49 OAK 18 Hard STUMP 109978 921.69 OAK 20 Hard DEAD 109984 926.41 BOXELDER 12 Soft DEAD 109986 927.94 OAK 16 Hard STUMP 109995 923.71 OAK 19 Hard DEAD Living 106493 917.07 17 13 Hard Living hardwood trees between 6" -19" Tag# Elevation Type Size Hardwoods 20" - 30" Status 100301 922.89 CHERRY 10 Hard Living 100304 934.91 OAK 12 Hard Living 100305 933.51 OAK 7 Hard Living 100306 932.82 OAK 6 Hard Living 100307 931.02 OAK 7 Hard Living 100309 926.15 OAK 7 Hard Living 100311 930.68 OAK 8 Hard Living 100313 927.85 OAK 8 Hard Living 100317 918.17 OAK 12 Hard Lining 100318 917.44 OAK 6 Hard Living 100319 917.82 OAK 9 Hard Living 100323 918.24 HACKBERRY 7 Hard Living 106483 911.61 HACKBERRY 10 Hard Living 106486 911.97 HACKBERRY 9 Hard Living 106488 911.80 HACKBERRY 10 Hard Living 106489 912.65 CHERRY 12 Hard Living 106492 918.33 HACKBERRY 7 Hard Living 106493 917.07 HACKBERRY 13 Hard Living 106495 914.81 HACKBERRY 7 Hard Living 106496 914.37 HACKBERRY 8 Hard Living 109959 914.88 HACKBERRY 13 Hard Living 109962 921.60 HACKBERRY 7 Hard Living 109963 922.09 HACKBERRY 7 Hard Living 109964 922.08 HACKBERRY 7 Hard Living 109966 925.10 CHERRY 11 Hard Living 109988 922.91 HACKBERRY 6 Hard Living 109969 919.14 CHERRY 6 Hard Living 109970 916.67 CHERRY 13 Hard Living 109971 919.80 HACKBERRY 9 Hard Living 109973 921.20 HACKBERRY 7 Hard Living 109975 928.99 OAK 13 Hard Living 109976 925.41 HACKBERRY 11 Hard Living 109977 923.16 HACKBERRY 6 Hard Living 109981 922.08 OAK 19 Hard Living 109982 925.53 HACKBERRY 7 Hard Living 109983 929.66 HACKBERRY 10 Hard Living 109985 928.31 HACKBERRY 9 Hard Living 109988 929.67 HACKBERRY 7 Hard Living 109993 916.87 CHERRY 19 Hard Living 109994 915.83 HACKBERRY 6 Hard Living 1099% 922.77 OAK 19 Hard Living 109997 921.78 HACKBERRY 7 Hard Living 110000 921.E6 CHERRY 12 Hard Living 43 65% Table 7 Tree Inventory Replacement Type Type Hardwoods under 20" 65% Hardwoods 20" - 30" 7.5% Specimen Trees over 30" 1.5% Replacement Per Code/Tree Removed - Soft > 24 26% Living 100% Living hardwood greater than 20" Tag # Elevation Type Size 20 Status 100308 928.43 OAK 20 Hard Living 100322 916.68 OAK 24 Hard Living 106498 912.43 OAK 23 Hard Living 109990 921.65 OAK 26 Hard Living 109991 921.30 OAK 23 Hard Living Living 106497 913.02 5 7.6% Soft Specimen hardwater greater than 30" 109998 918.41 OAK 33 Hard Living 1 1.5% Living softwood greater than 12-24" 100310 928.27 BOXELOER 20 Soft Living 100316 924.51 ELM 14 Soft Damaged 100321 916.40 BOXELDER 16 Soft Living 106487 911.74 ASPEN 14 Soft Living 106490 912.00 ASPEN 16 Soft Living 106491 915.25 BOXELDER 12 Soft Living 106497 913.02 BOXELDER 16 Soft Living 106499 911.60 BOXELDER 13 Soft Living 106500 913.48 ELM 19 Soft Living 109957 913.05 ASPEN 19 Soft Damaged 109974 925.76 BOXELDER 13 Soft Living 109979 92159 ELM 13 Soft Living 109980 921.00 ELM 15 Soft Luing 109987 929.95 ELM 14 Soft Living 109989 923.15 BOXELDER 13 Soft Living 109992 917.26 ELM 15 Soft Living 109999 919.41 BOXELDER 13 Soft Living 17 261. Total Trees 66 100% After determining the amount of lotted area, right of way, ponding, and grading that would be needed to complete the development work, an estimate of the total forested area removed was made. Much like many areas of this narrative, while we believe the numbers we are using are reasonable, more exact acreages will be determined with the PDO submittal. These calculations and tables are meant to express the likely outcome and set up a reasonable methodology for tree replacement. Our hope is that we will be able to actually increase the area of woods to be saved. For now we are assuming that up to 10 acres of woods will be removed for ponding and grading outside of the lotted area and right of way shown on the concept plan. These are the most difficult items to estimate their potential impact. 12 Table 9 Excess Tree Removal Calculation Total Tree Cost at $325 Removal Type Acres # of Trees* Natural Forest 39.2 2,587 Removal Allowance 40% * 39.2 Ac = ---------------------------------------------------------------------------------------------------------------------------------------------------------- 15.7 1,035 Proposed Tree 920 $298,927 Removal 67% 26.4 1,742 Excess Tree Removal** 20% 10.7 708 *Number of trees = Acres * 66 trees/acre **Trees saved include a portion of the red pine plantation Based on the initial calculations there are 10.7 acres of trees being removed over the amount allowed by the City's tree ordinance. The table below shows the number of replacement trees and monetary equivalent that would be required if the loss was being mitigated with cash. Table 10 Replacement Per Code (Per Sampling) - if all cash Category B Mitigation # of Replacement Trees Required 100% 708 1,288 212 64 I 1,564 $508,176 As a part of the PDO we are proposing to handle the tree mitigation through planting additional trees and implementing a restoration plan to improve the health of the trees that remain as well as restore portions of the intermittent stream that runs in the ravine. The restoration is described in greater detail on the next section of the narrative. The alternative PDO replacement calculations are shown on Table 11. 13 Total Tree Cost at $325 Removal Type % # 2 x 4 x 6 x Replacement per tree Hardwood less than 20" 65% 460 920 920 $298,927 Hardwood greater than 20" less than 30" 7.5% 53 212 212 $68,983 Specimen Hardwood greater than 30" 1.5% 11 64 64 $20,695 Softwood between 12" and 24" 26% 184 368 368 $119,571 100% 708 1,288 212 64 I 1,564 $508,176 As a part of the PDO we are proposing to handle the tree mitigation through planting additional trees and implementing a restoration plan to improve the health of the trees that remain as well as restore portions of the intermittent stream that runs in the ravine. The restoration is described in greater detail on the next section of the narrative. The alternative PDO replacement calculations are shown on Table 11. 13 Table 11 Replacement with credit for Restoration - PDO Flexibility Actual Category B Tree Trees Equivalent Extra Street Trees 2.5" BB 40 40 Reforestation Trees 1.5" BR (2:1) 500 500 (1,000 actually being planted — However per B tree replacement equivalent 2 bare root 1 category B replacement) Extra Lot Trees 2 x 2.5" x 138 276 276 (Above the 4 required by code) Ravine Restoration $* 750 (*Tree Equivalent $250,000 +- for Restoration Work) 816 1566 The table above shows that the with the development work we will be planting 816 trees towards the replacement of the removed trees, based on the Category B replacement table. To make up for the additional replacement trees approximately $250,000 in restoration and reforestation work will be completed as a part of the development work. 2. Restoration Concept As a part of the tree mitigation we are proposing to improve the portions of the forest that are being saved with an emphasis on the greenway corridor on each side of the ravine. The ravine has great potential for fostering ecological diversity as well as scenic value. This section of the narrative provides a general description of a restoration approach. A more specific plan will be created as a part of the PDO. The intent of this section is to give enough specifics to see the value of off -setting some of the tree mitigation requirements with restoration work within the forest. Our goal in restoring the open space is to create a beautiful natural environment that can be shared with the neighborhood and public at large. As shown in the restoration plan (Figure 10), we have provided for a paved regional trail along the southern border of the property and have linked that trail within and around the Amundson property using natural earthen trails much like you would find in a DNR park. While we do not yet have all the specific details designed, we have worked on several projects that have entailed significant restoration activities and therefore have a general idea of what we can achieve. The concept restoration plan identifies six areas for restoration activity: 1. Forest restoration areas, 2. Ravine/greenway restoration areas, 3. Stream restoration area, 4. Red pine plantation, 5. Reforestation areas, and 6. Pond buffers. 14 Figure 10 ! ) 3 6 6 7 _10 2 \` \ 2 I 4 — g 10 ` �� 3 31 / —w� 11 12 4 6\� / 3 ( — 1 �\ t3 t 17 1 v O g \ 118 I 11 (` 16 191 20\ 9 *�4 16 \` 4i —5'1 1 14 12 14 13 � 17 2 2 18 \ 3 ti 19 20 p 3 4 0v, 11 , 13 C 1 g 1, 12 g 1 it 9 I t0 9 1 2 3 4. 6 6 7- n 3. Restoration Activities Restoration Plan 4-2&2017 Restoration activities are described in detail below. 7 8 9 4 6 7 3 17 26 1 1 2 / 1 24 i I I6 1 I 2 23 J I 22 I �'� Restoration Areas/Zones - Forest - Ravine/Greenvlay 10 stream - Red Pine Plantation - Reforestation 7 6 I Pond Buffers p 3 4 0v, 11 , 13 C 1 g 1, 12 g 1 it 9 I t0 9 1 2 3 4. 6 6 7- n 3. Restoration Activities Restoration Plan 4-2&2017 Restoration activities are described in detail below. 7 8 9 4 6 7 3 17 26 1 1 2 / 1 24 i I I6 1 I 2 23 J I 22 I �'� I 3 4 21 20 1 1 14 13 2 3 4 I 7 10 i 12 11 ' 9 17 16 I 1,. 7 6 I 10 I is 4 1 I 13 1 y a� %7 10 11 12 II t 2 3 4 6 / \ Regional Trail ••••••••• Informal Pathways 1. Forest Restoration Areas —These are areas of the site which are forested and not part of the white or red pine plantations. There are two general types of wooded areas within the forest restoration areas: aspen -oak forest and oak forest. Aspen -oak forest —The aspen -oak forest areas include big -toothed aspen, red oak, northern pin oak and bur oak. A brushy understory was a common feature of this forest historically and the ground layer plants consisted of comingled shade -tolerant and shade -intolerant plants. Currently aspen -oak forest is distributed in patches across the natural forest. Where it was observed, it was not extensive. It is a generally young forest and has become denser and more shaded since the 1950s. Due to increasing shade and the loss of shade -intolerant grasses, wildflowers, and shrubs, this forest type has experienced a decline in its plant diversity over the last few decades. Oak forest — The oak forest is the dominant forest type. Oak trees including red, bur, northern pin and white oak are dispersed throughout the area. Cottonwood trees are the next most common large tree after the oaks. The presence of cottonwoods suggests that open, sunny conditions previously occurred at locations in the oak forest where the cottonwoods could 15 become established. Trees of other native species included black cherry, hackberry, red cedar, green ash, basswood, and American elm. In some areas of the forest the larger trees are often surrounded by young red oak, ironwood, black cherry, hackberry, and common buckthorn. Many large trees in the woodland area have open -grown crowns yet their lower branches have been shade -pruned or are in the process of dying. The ravine area is populated with a number of significant oaks and appears on aerial photos dating back to the 1940s to be the longest standing large area of forest on the property. Throughout the forest, common buckthorn and some Asian honeysuckle are present and impeding native vegetation growth in the ground story. In other areas, Siberian elm is also invading portions of the understory and old forest openings. In the ravine area box -elder and green ash, which have colonized the oak and aspen -oak forest from nearby rivers and deep valleys, are also prevalent. Selectively thinning the canopy of undesirable trees and removing the common buckthorn and other invasive trees and shrubs from the understory would be the most likely restoration activity in the forest area. Once completed a selective overseeding of native woodland plants can be evaluated as to whether it is necessary or not. 2. Ravine/Greenway Restoration Areas — A large portion of the older forest is located primarily but not exclusively to the west of the ravine. The forest characteristics of the area are described above, this area generally fits the oak forest description. The ravine itself is in large part a waterway that is being used to convey storm water from the projects to the north of Amundson, through the Amundson property. Portions of the ravine streambed have been straightened and the meanders filled over time. Today there are areas that have been filled with sediment and other areas where banks are being undercut, resulting in sediment being transported downstream. In the ravine area, in particular, thinning of the box elder and green ash may be needed to open the canopy for native trees and to stimulate and expand the ground story vegetation which binds the streambank sediment. Some removal may also be needed to gain access to portions of the streambed that require repair. 3. Stream Restoration Areas — Generally, restoration of the stream could include some streambank stabilization, improving/restoring critical meander locations, stabilizing some areas that are undercutting or being scoured. • Restoration techniques that may be employed: o Selectively thinning forest canopy to allow for more robust understory vegetation o Brush mattresses o Live staking (willows, dogwoods) o Native seeding o Planting of live perennial plugs o Rock check dams, vanes, and 1 -hooks o Selective thinning of canopy to provide for understory vegetation growth 16 o Shaping/sloping eroded stream banks and revegetating 4. Red Pine Plantation —As described in the tree section of the narrative there are two types of pine plantations on the property, red and white. An application has been made to harvest most of these areas for lumber and/or pulp. This would be done concurrent with the development of the property. Some areas of the red pine plantation will be preserved. In order to help the pines preserved during development some thinning will be needed. Also, some planting of new trees is also warranted to help off-set a future possible decline of this area. Much like the oak forest, there are also areas of the red pine plantation where the understory is dominated by common buckthorn, and this would be removed. 5. Reforestation Areas —As a way to expand and connect the preserved forest areas, certain non- forested areas will be restored to forest. This will entail planting young trees in these areas and protecting them while they get established. 6. Pond Buffers— In order to treat the storm water and in part restore the streambed, ponds will be created by grading at discrete locations within the forested area. It would be our intent to plant native buffers around these areas as a part of the restoration plan. 3.Trails We are proposing to include a trail connection along the southern property. This is part of the City's regional trail plan and provides a great link between the Silverwood development and the Highland Hills Corridor. Figure 11 OV 615T ST 60TH STs - 1 LJJ "40LEYAVEs 6TST SYs� 1 WGHL AIID HL II y UITJ `' H M HILLc!■�_Li SHILL' jo1HTE PL.s •!' �i�f.�#araylr�_ •�►h.r•�• ■ .� PAR1L. 9� -F IJ ••.:1 .11OMF, lyq r• Usting Trail - I, H ,L, � � • • • • . Proposed Regional Trail Connection s � v a rs - u lRK GJ T61D 9{'E S GEGRO� O H.O,, Po AND IIILLS• _ Z ]J 631T1 STs r G L AILWI\V 'LOWER OR f LUESTEM LV 66TH .ST 9_ _-. 6 y i W . f. This regional link will need to extend through some significant topography making it a very interesting trail, but one that would likely not meet the typical grade standards found in other areas of the City. In some limited areas, we may need to increase the grades to 20-25% (1' of incline for every 4' of trail length) More exact trail locations will be included with the preliminary plat and final locations will be field verified with City approval. While the regional connection is significant for the City as well as the 17 development, the internal pathway connections may become a more important amenity for the neighborhood. A number of the informal pathways exist on the property today (see Figure 12). We are proposing to use in portions of the existing trails in conjunction with newly created trails to create an informal trail around the entire property. These trails would look more like trails you would expect in the Boundary Waters or at a state park. It is possible that these trails could be located in the buffer areas where several are located today. Buffer widths will be increased to make up for any trail encroachment. We intend to leave the trails as earthen trails that would be occasionally mowed and maintained but would not have a formal bedding. Below are a couple winter pictures of the trails currently on the property. Figure 8 VII. Concept Plan — Details: 1. Sewer and Water Sewer and water service is available to the property at several locations. At this time, it is our intent to service the property east of the ravine at one or both of the sewer and water connections to the east, one on 61St Street and one just south of the trail connection in Silverwood and at the sewer connection to the west located along Hadley Ave. S. north of 65th Street S. As is mentioned later in this narrative there may be engineering standards where we need some flexability. One that may need some consideration is allowing manholes to be off -centered in the roadway. 18 2. Storm Water With our plat, we will create a plan that meets the South Washington Watershed District (SWWD) storm water requirements. As a part of our proposal we will look towards using innovative storm water treatment techniques that could save trees. We have worked on several projects that have won awards for our implementation of unique storm water treatment methods. We have a significant amount of experience and while many of the standards we used to implement were considered innovative, such as infiltration areas, and are now standard and required, there are still ways to expand the techniques and systems used to treat storm water. As shown we are estimating a need for 4-7 acres of ponding. We would like the City to consider modifying its typical pond standard to reduce the footprint of the ponds. The current standard calls for an aquatic bench (which is common) and a maintenance bench (which is less common but not unusual). Since we are all trying to provide appropriate storm water treatment yet save a significant number of trees we would request that the City look as eliminating one or both of the benches for ponds within the wooded areas of the property and/or allow 3:1 slopes down to each bench. At this time, we do not have a specific proposal but intend to look for alternatives and understand that these will need to be reviewed and approved by the City and watershed. 3. Street/ROW Considerations Generally, we are following the City roadway standards for residential streets. We are providing for a 60' of right of way and a 28' roadway face to face with surmountable curb. While this is what we have incorporated into our plan we would be happy to consider reducing either the road width or right of way width or both. We believe that an additional acre of trees could be saved by reducing the ROW to 50'. We would then also like to look at using a 28' back to back standard for the roadway. In other heavily forested projects we have developed we have had cities approve as narrow as 24' back to back roadways. We understand that this may not be a policy the City wants to consider so we are asking for consideration, more as a partnership than as a demand. We are setting aside 40% of the land that we are purchasing and it would be great if the City wanted to help increase, even more, the amount of open space we are able to provide. We confirmed with staff that access to Hadley Ave S. will not require a turn lane. Therefore, we have not indicated a turn lane on the concept plan. In addition to consideration for street and ROW widths, and possibly more important, will be flexibility to the City's roadway standards. Due to the extreme topographical changes, flexibility will be needed to the City's vertical curve standards. It is likely a 20 MPH vertical curve will be needed to complete the roadways as shown. While we will try to stay within the 10% grade maximum there may be limited areas where we need to exceed that standard. Additionally, we will likely need flexibility to any restrictions requiring the grade within 100' of an intersection to be at 1% or less. 4. Sidewalks 6' sidewalks will be incorporated on one side of the street. General locations shown in streetlight and sidewalk plan 19 Stantec May 15, 2017 File: 193802266 Ryan Burfeind City of Cottage Grove 12800 Ravine Parkway Cottage Grove, Minnesota 55016 Reference: Amundson Property (Concept Plan Review) Dear Ryan, Below are review comments for the proposed Amundson Property Concept Plan sent to Stantec on April 28, 2017: Street Comments: 1. The concept plan proposes a 61 st Street South connection to the east, this connection is recommended as shown. 615+ Street South has currently been extended to the proposed connection point in the existing development. 2. The concept plan proposes two southern connection be extended to the south property line of the project, these two connections are recommended as shown. Note, as these two streets extend south to 65th Street it is recommended that they connect, and one connection be made at 65th Street. This connection will have to be reviewed and approved by Washington County. 3. The concept plan proposes one western connection to Hadley Avenue, this connection is recommended as shown. Based on the current alignment and configuration of Hadley Avenue the proposed location makes the most sense from a sight distance and topography perspective. Sanitary Comments: The western half of the proposed development will have to be service by the sanitary sewer located in Hadley Avenue, approximately 1 100' south of the development. Based on record plan information the 8" sanitary sewer has an invert elevation of 841.73. Note, when the sanitary sewer is extended north to the development, anticipate the sanitary sewer to be between 15 to 40 feet in depth (In Hadley and within the development). The entire road width of Hadley Avenue will be disturbed during sanitary installation and will be required to be reconstructed. 2. Through easement or land acquisition, an option to provide sanitary sewer to the western half of the proposed development is to extend sanitary sewer north of 65th Street. Based on record plan information an 8" sanitary sewer stub has been installed with an invert elevation of 842.89 (sanitary stub is located near the southwest corner of 7206 65th Street). 3. For the Western half of the proposed development, if the property to the south of the project is developed as low density residential and the property to the west of the property is also redeveloped, a slight surcharge may occurjust north of the intersection of Timber Trail Lane South and Timber Ridge Lane South where the sanitary sewer line joins the City's trunk sewer system. The eastern half of the proposed development will have to be serviced by one of the two sanitary sewers located in 61St Street South (adjoining development) or 63rd Street south (just south of the development). Based on record plan information the invert to the sanitary sewer manhole in 61 st Street is 902.35 (8" sanitary sewer). Based on record plan information the invert to the sanitary sewer manhole in 63rd Street is 896.51 (8" sanitary sewer). Although sewer capacity is not an issue, there may be cover issues in this portion of the development to tie into these existing structures. The City requires a minimum of 12 feet in depth for all sanitary sewer. It is also worth noting that minimum allowable pipe slope for 8" sanitary sewer is 0.4% and 0.28% for a 10" sanitary sewer pipe. Water Comments: 1. 8" DIP water main exists in Hadley Avenue, approximately 1100' south of the development. This water main should be extended in Hadley Avenue to the north property line of the development (proposed street connection and water main loop). 2. 8" DIP water exists in 61St Street South and should be extended west through the development (water main looping). 8" DIP water main also exists in 63rd Street South that could be used to loop water main. 3. 8" DIP water main should be extended in proposed streets to the southern limit of the development (future water main looping). Stormwater Comments: 1. Rate Control: Please refer to the attached map for maximum discharge rates allowed for the Amundson Property. 2. Ponding: Pond emergency overflow (EOF) should be set at or above the 100 -year High Water Level (HWL) and be armored with rip rap to protect slopes from erosions. 3. Ponding: Pond inlets should be set at the NWL of the pond. 4. Water Quality: To meet the MS4 permit, a net reduction to TSS or TP is required or a removal efficiency of 80% for TSS and 50% TP, whichever is greater for the project site. Design with community In mind 5. Water Volume: To meet the City's volume control requirements, the site must infiltrate 1 " of runoff from new impervious areas of development. This site is located outside of the City's wellhead protection area and soils in this area are conducive to infiltration. 6. Storm Sewer: To meet the City's requirements for storm sewer design, please provide calculations for a minimum 5 -year storm sewer design using the Rational Method. Miscellaneous Comment: 1. Exploratory soil borings should be taken throughout the site to ensure the water table or unknown bedrock will not impact the design of the project. Regards, Stantec Consulting Services Tyler K. Johnson, PE Phone: 651-604-4767 tyler.johnson@stantec.com David R. Sanocki, PE Phone: 651-604-4905 Dave.sanocki@stantec.com Design with community In mind f - \ kE� . LL 0 Fn ox � LU . .. r t/ . 7/,E� . ) k . \ `} 2 / k / k / /( # i � U, i- o§ t =oE E - 2 �.� °>m�e On . C) CL it• 2 § O 7 • �` ' i ;\ o° : = a { 2« / f - \ kE� . LL 0 Fn ox � LU . .. r 0 22§mR . 7/,E� . . `m2\&. - . ZZW.Q< 2 m§§mo.:.�, U, .— ix On . it• kit f -