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Bluffs at Lake Lucy - DC Review - SBI Responses 091620SP-2 Conveyance of Outlots At the time of recording the final plat, the following outlots must be conveyed to the City free and clear of any encumbrances: Outlot A 12.67 acres Parkland, trail, wetland & stormwater pond Outlot B 2.17 acres Wetland & stormwater pond Park and Recreation 1. All trails and sidewalks shall be constructed as shown on the street plan or as modified by construction plan redlines. 2. All trails shall meet all City standards for trail construction. Planning 1. All property within the plat must be included in The Park PUD (“PUD”). 2. All lots and homes must be developed consistent with the standards in the Compliance Table. 3. Documents establishing a homeowners association for the plat must be submitted by the Developer with application for final plat approval and recorded with the final plat against the property within the final plat, except for Outlots A and B. The HOA documents are subject to review and approval of the City Attorney. Engineering 1. Any requirements set by the MCES to work within the MCES’s sewer and utility easement shall be addressed by the Developer. Response: Acknowledged. 2. An executed agreement between the developer and the MCES allowing work within the MCES’s easement shall be provided to the City prior to the issuance of grading permits. Response: Acknowledged. 3. Developer shall continue to coordinate with Carver County (“County”) and the City regarding future improvements to Galpin Boulevard. The Developer shall address all conditions associated with the County’s review. Also see Condition 7. Response: Acknowledged. 4. The Developer shall abandon all existing wells and septic fields in accordance with all federal, state, and local regulatory agency standards, and obtain all necessary permits for said abandonments. Prior to commencement of abandonment activities, a copy of all required permits from the appropriate regulatory agencies shall be provided to the City. Response: Acknowledged. 5. Grading within bluff setbacks is subject to review and approval by the City prior SP-3 to grading. Response: Acknowledged. 6. The Developer shall submit revised grading plans and stormwater plans so that no stormwater runoff flows directly onto the public trail. Response: The trail grading has been revised and storm sewer has been added. 7. Final grading plans, including pond locations, sizing and analysis, along with right-of- way dedications off Galpin Boulevard, shall conform to the future Galpin Boulevard reconstruction project. Cross reference of grading plans, profiles, and respective cross sections are to be provided at key locations such as intersections, ponds, or other special features required by the County and City for review prior to acceptance and recording of the final plat. Response: Acknowledged, with the understanding that the plans as proposed work for the future Galpin Blvd improvements. 8. All retaining walls exceeding four (4) feet in height shall have plans and details prepared by a registered engineer or landscape architect prior to issuance of building permits. Response: Acknowledged, retaining wall design plans have now been provided to the City, by the developer. The retaining wall engineering plans were prepared by The Hanson Group, dated August 18, 2020. 9. All newly constructed streets and the extension of any existing streets shall be public streets, owned and maintained by the City, after acceptance of the public improvements by the City Council. Response: Acknowledged. 10. All newly constructed public streets shall be designed to meet the current standard specifications and detail plate for residential streets (Detail Plate #5200), unless otherwise directed by the City Engineer. Response: Acknowledged. 11. The Developer shall abandon the existing access, construct a new access and provide an access easement for parcel 25.0100400 onto “Della Drive”. Response: The plans have been updated to show the proposed driveway for 7011 Galpin Blvd. 12. A water service lateral shall be stubbed off the of “Della Drive” water main for the future connection to parcel 25.0100400. Response: Water service lateral added to plans as noted above. 13. A geotechnical engineering shall be on-site during grading operations. If groundwater is encountered during grading, grades shall be adjusted to maintain a three foot separation from the bottom floor elevation and adhering to the recommendations of the soil engineer on site. Changes to grades shall be submitted to the City for review and approval. Response: A geotechnical engineer will be on-site during the grading operations. 14. All curb ramps shall be constructed to meet ADA standards and the City’s Detail Plates #5215-5215D. Response: All curb pedestrian ramps will be constructed to meet ADA standards. SP-4 15. A detail of the proposed street lights shall be provided prior to the issuance of building permits. Response: The developer will provide a street light detail for the City review, prior to the street light installation. 16. Street lights within the development shall be owned and maintained by the electric utility company, be installed at all intersections and at the end of each cul-de-sac subject to review and approval by the City prior to issuance of building permits. Response: Acknowledged. 17. All newly constructed water mains shall be public water mains, owned and maintained by the City, after acceptance of the public improvements by the City Council. Response: Acknowledged. 18. Water mains located on Della Drive shall be tied into the high-pressure zone located on Galpin Boulevard. Water main extensions on Topaz Drive and Lucy Ridge Lane shall be tied into the existing water main stubs (low-pressure zone). Response: Water main located on Della Drive tied into the high-pressure zone located on Galpin Boulevard. Water main extension on Topaz Drive and Lucy Ridge Lane tied into the existing water main stubs (low-pressure zone). 19. The water main located on Della Drive shall be tied into the existing stub off Ruby Lane and a gate valve near the connection point shall be installed. The gate valve shall be closed to separate the pressure zones. Response: Water main located on Della Drive tied into the existing stub off Ruby Lane with gate valve near the connection point. Gate valve will be closed to separate the pressure zones. 20. The Developer shall field verify the location of all water main taps to the existing public mains off Galpin Boulevard prior to commencement of any utility construction and update the plans accordingly. Response: We have had the minor utilities located and had a contractor verify the location and depths of the existing raw water line on the east side of Galpin Blvd. 21. The Developer’s contractor shall schedule a preconstruction meeting with Engineering and Public Works Utilities departments prior to the commencement of any work to the water main installation and tapping from Galpin Boulevard. Response: Acknowledged. 22. Updated plans indicating the location of all underground utilities on the east and west side of Galpin Boulevard, along with plans and profiles of any utility crossings on the east and west side of Galpin Boulevard, shall be submitted for review and approval prior to the commencement of any utility construction. Response: The location of all underground utilities on the east and west side of Galpin Blvd at the watermain connection point have been located and are shown on the plans and the raw water line has been located and the depth has been determined. 23. Water mains shall be constructed at a minimum of 7.5 feet below grade, or insulated, and constructed in conformance with the City’s standard specifications and detail plates. Response: All water main to be constructed at a minimum of 7.5 feet below grade, or SP-5 insulated, and constructed in conformance with the City’s standard specifications and detail plates. 24. Cluster valves located around water main tees shall be installed at a minimum of five feet from the tees to the valves, where feasible. All valve locations and any other water main appurtenances shall be reviewed and approved by the Engineering and Public Works departments prior to the commencement of any utility construction. Response: Acknowledged, gate valves are proposed as shown, please provide with any revisions deemed necessary. 25. All comments and conditions regarding fire appurtenances, spacing, and location set forth by the Fire department shall be addressed by the Developer. Response: Acknowledged. 26. All newly constructed sewer mains shall be public sewer mains, owned and maintained by the City, after acceptance of the public improvements by the City Council. Response: Acknowledged. 27. All conditions set forth by the MCES for the direct connection and installation of an access manhole to their trunk line shall be addressed by the Developer, and all permits required for the connection and installation of the manhole shall be obtained prior to the commencement of construction. Response: Acknowledged. 28. The Developer shall ensure the City’s sanitary sewer nomenclature is incorporated in the construction plans. Response: City of Chanhassen sanitary sewer nomenclature is now incorporated in the construction plans. 29. PVC sanitary sewer pipes that will be constructed at a burial depth of 0-16 feet shall be constructed of pipe class SDR 35, burial depths of 16-26 feet shall be of pipe class SDR 26, and burial depths of greater than 26 feet shall be of pipe class C900. Response: PVC sanitary sewer pipes will be constructed appropriately in relation to burial depth and the respective pipe class. 30. Inverts that have a 20-inch or greater differential shall be supplied inside drops per City standards and be constructed per the City’s Detail Plate No. 2104. Response: Sanitary sewer inverts with a 20-inch or greater differential supplied with inside drops per City standards and details. 31. No roadway connection shall be made to Topaz Drive. Response: Roadway connection removed to Topaz Drive. 31. Untreated or stormwater from lots not captured and routed to treatment facilities, particularly in backlots, require a conveyance system to be installed to route stormwater to treatment basins. Response: Most of the site stormwater from homes has been directed towards storm sewer system to be treated. 32. No sump structures shall be installed in backyard pickups. SP-6 Response: No sump structures in backyard pickups. 33. Access routes to storm basins shall have a slope no greater than 3:1. Response: Access routes to storm basins have slope no greater than 3:1. 34. Driveways shall be setback in accordance section 20-1122 of City Ordinances. Response: Driveways to be setback in accordance with section 20-1122 of City Ordinaces. 35. All driveways shall be located outside side lot drainage and utility easements. Response: All driveways to be located outside side lot drainage and utility easements. 36. A $300 fee per light shall be collected with the development contract for electricity costs for the first year of operation. Response: Acknowledged. 37. The contractor shall contact the City inspector for inspection of all insulated pipe crossings. Response: Acknowledged. 38. For all storm sewer plans: any HDPE pipe shall be called-out as “N-12” in accordance with City standard specifications. Response: All HDPE storm sewer pipe shown as XX” N-12 HDPE. 39. All plans, specifications, project manuals, and submittals shall be in conformance with the most recent version of City Standard Specifications and Detail Plates (http://www.ci.chanhassen.mn.us/436/Standard-Specifications-Detail-Plates). Response: The plans and specifications call out the City standard detail plates. 40. As the property is within the Lake Ann Sewer District, a sewer interceptor charge and a sub-trunk charge will be due at the time of building permit issuance for each lot. For 2020, the Lake Ann Interceptor Fee and Lake Ann Sub trunk Fee are $1,970.00 and $2,068.00, respectively. Response: Acknowledged. 41. All retaining walls within the development shall be owned and maintained by a Homeowners Association. Response: All retaining walls within the development will be owned and maintained by the Homeowners Association. 42. All sidewalks not abutting platted Lots (e.g. on Della Drive abutting Outlot B) within the development shall be owned and maintained by a Homeowners Association. Response: All sidewalks not abutting platted Lots within the development will be owned and maintained by the Homeowners Association. 43. Any retaining wall located within a public drainage and utility easement shall enter into an encroachment agreement with the City. Response: Acknowledged, please provide the encroachment agreement so we can prepare the documents for the walls. SP-7 44. The “Specifications for The Bluffs at Lucy Lake” prepared by Sathre-Berquist, Inc. provide Special Provisions that are not in accordance with the City’s Standard Specifications or Detail Plates. These Special Provisions shall be updated to either amend any modification that would conflict with the City’s Standard Specification and Detail Plates or be removed entirely. If the Developer and their Engineer elect to modify the Special Provisions, the City will provide redlines to assist with their modifications, however in accordance with Engineering Condition 39, all plans, specifications, project manuals, and submittals shall be in conformance with the most recent version of City Standard Specifications and Detail Plates (http://www.ci.chanhassen.mn.us/436/Standard-Specifications-Detail-Plates) and their conformance is ultimately the responsibility of the Developer. Response: The special provisions have been removed from the Specifications Book. 45. On sheet 4 of 4 on the Final Plat: Block 3 Lot 4’s ten (10) foot drainage and utility easement located in the middle of the lot shall be twenty (20) feet wide to accommodate maintenance activities for the designed drainage on the lot; the right-of-way shall be extended at the end of “Topaz Drive”, between Block 3 Lots 5 and 6 to reflect the approval of the Preliminary Plat for “The Park”; Block 3 Lot 8’s southerly drainage and utility easement is illustrated at ten (10) feet wide which is oversized, it is possible to lessen this width to five (5) feet. Response: The 10-foot d&u easement has been left on the final plat as it is noted on the markup as 10 or 20 feet. 46. On sheet 1 of 23: In the zoning index, cul-de-sacs are called out to have a 45’ radius, this shall be updated to 48’ per Detail Plate #5205; the “City Project No.” is 2020-12, update accordingly. Response: Updated sheet 1 of 23 accordingly. 47. On sheet 2 of 23: It is recommended that detail plates remain on the sheets specified as “Detail Sheets” (sheets 17-23) and not be incorporate on random sheets throughout the plan set for clarity which will also allow for larger plan views on the corresponding sheets; the remnant driveway entrance north of “Della Drive” shall not be removed in association with the development, the City will assess its removal upon commencement of the Galpin Boulevard improvement project; throughout the Street and Storm Plans it was found that draintile does not extend on both sides and the full extents of the streets, the plans shall be updated to ensure draintile is installed on both sides of the street per Detail Plate #5200 and extend the full length of the proposed streets; street lights shall be located more closely to hydrants at the end of cul- de-sacs (where applicable) in order to allow for better snow storage practices; in addition to changing the castings at the end of Ruby Lane, a note shall be added to coordinate with the City to assess if additional repairs are required to the catch basins; Street Note #2 shall be updated to clarify sidewalks are 6” thick and curb ramps shall be constructed in accordance with Detail Plate 5215-5215D; it is recommended that Street Note #4 be updated to eliminate the use of plastic rings as the City prefers concrete rings; add to Street Notes the requirement that all work outside platted areas are to be coordinated with the City and Residence, which includes R&D of Ruby Lane and Laky Lucy Ridge, prior to construction activities commencing; add to Street Notes that all signs associated with the development are to be furnished and installed by the contractor in coordination with City review, and that signs within County right-of-way will require coordination with the County; ensure that all trail intersections have a 20’ radius as required by Detail Plate #5216; add to Street Notes that cluster mailboxes shall be installed at the throat of cul-de-sacs, this is required to facilitate better snow storage practices at cul-de-sacs. Response: Detail plates to remain on title sheets for Street and Sanitary & Watermain plans, as SP-8 well as being included on the Detail Sheets. Proposing to remove driveway entrance north of Della Drive with grading plan while keeping pond access route as shown. Extended draintile along both sides and the full extents of the proposed streets. Streetlights have been revised to be allow for better snow storage, please provide revisions to locations if preferred. Added note to coordinate with the City to assess additional repairs if required to catch basins along Ruby Lane. Revised Note #2 and #4 while adding additional notes as listed above to meet City recommendations. 48. On sheet 3 of 23: Horizontal scales shall be provided on all profiles within the plan set; while driveway grades are provided, the general location and layout of proposed driveways and building pads are not illustrated, the plans shall be updated to illustrate proposed driveway and building pad locations for review and approval by the City; the newly proposed sidewalk along “Della Drive” shall terminate at the north side of the cul-de-sac throat; an exhibit illustrating the proposed driveway location and grades to parcel 25.0100400 shall be submitted for review and approval prior to the commencement of grading, the location of the driveway entrance, in accordance with Carver County’s review memo, shall be no closer than 100’ to Galpin Boulevard and grades along the proposed driveway shall meet City Standards, lastly the water service must align with the newly proposed driveway location. Response: Horizontal scales are shown on the plan sheets. We have provided general location and layout of proposed driveways and building pads on separate exhibit. Sidewalk along Della Drive now shown to terminate at the north side of the cul-de-sac throat. Exhibit proposing driveway location and water service to parcel 25.0100400 (7011 Galpin Blvd). 49. On sheet 4 of 23: The dimensions of the cul-de-sac bubble at the end of Topaz Drive shall be illustrated; the R&D note for the area of Lucy Ridge Lane calling out “Restore Yards: irrigation and sod” shall also include all privately owned underground improvements (e.g. invisible dog fences); plans to be updated to illustrate clearly that the sidewalk along Lucy Ridge Lane shall connect between the newly proposed alignments to the existing “R&D” areas; the newly proposed sidewalk along Lucy Ridge Lane shall be extended to and terminate at the east side of the cul-de-sac throat; the sidewalk along Topaz Drive shall be removed; the plan and profile stationing for Topaz Drive shall begin from the end of the cul-de-sac (reverse stationing); there appears to be an erroneous call out near Topaz Drive profile (“CL-CL Lucy Ridge Lane Sta: 06+48.90”), update accordingly; the extension of public trail dead-ends with no turnaround provided, a turnaround shall be shown on the plans for review and approval. Response: Dimension labels now shown on cul-de-sac bubble at end of Topaz Drive. R&D and restore note has been revised appropriately, and erroneous CL-CL label has been removed. Topaz Drive plan view stationing has remained the same, but profile view has been revised to show in same direction of stationing. Trail connection, extension, termination, and removal comments have all been revised and addressed appropriately. 50. On sheet 5 of 23: As no sanitary mains are proposed to be C900 note 1 is unclear, clarification is required; note 2 shall be updated as sewer services shall be 6” SDR 26 solvent, non-gasketed weld joints; note 4 shall be eliminated as no DIP will be allowed or is proposed in the sanitary sewer system, only PVC C900 when required (e.g. at the inside drop connection); note 11 shall be updated to state that all services shall extend to the property line (per Detail Plates #1005 and 2001) unless otherwise noted as services may extend past the property line where sidewalk is located; note 13 shall be updated to correctly call out the City’s standards as “Standard Specifications and Detail Plates”; note 13 shall be updated to state that the exception SP-9 is for sanitary and water services past the property line or curb stop which is in-line with City Ordinances, for clarity; note 17 shall be updated to state all watermain shall be PVC C900 DR 18; note 19 must be updated to provide the contractor the City’s Utility Department phone number 952-227-1300; a note must be added that RieberLok gaskets on all C900 PVC shall be used in accordance with City Standards. Response: Appropriate revisions to note 1, 11, 13, 17, and 19 have been made, as well as the removal of note 4 and additional ReiberLok gasket note. Note 2 has been revised to be 10’ beyond the property line to be past the minor utilities in the D&U easement. 51. On sheet 6 of 23: The plan view shall be adjusted or an inset provided illustrating the water main connection required of the proposed water main between Lots 3 and 4 and the existing water main off Ruby Lane; the water main shall be located on the southern side of Della Drive to facilitate separation from CBMH 19’s sump structure, limit the depth of any possible water main lowering, and ensure that the water main does not go lower than the sanitary sewer main’s grade; a detail shall be provided specific to MH 1 which should account for the compaction/fill around and up to the 8” PVC C900 connection for the inside drop; show all utility crossings, including water main, in all profile views including the inset for the inside drop MH connection; all existing utilities need to be identified in the profile views, especially under, east and west of Galpin Boulevard to ensure no conflicts are present; due to the complexity of notes and existing utilities near around Galpin Boulevard where the proposed water main will tie-in to the existing water main, a separate inset shall be provided; the call-out for connect to existing shall be updated to “connect to” and not “wet tap” and include reference to the high pressure zone; casing is required for the extents of water main proposed under Galpin Boulevard; a gate valve shall be installed on the east side of the tee located near 8+60; certain areas of sanitary sewer are called out at less than 0.5% grade, it is highly recommended that grades be adjusted to maintain a minimum of 0.5% for constructability as any sanitary sewer mains below the minimum allowable grade will be required o be removed and re-installed; where grades are greater than 16’ sanitary sewer main shall be PVC SDR 26, i.e. at locations east of MH 2 or north of MH 8; clarify the nomenclature “HBOE”; update line work for proposed storm sewer in profile to follow the color style consistently (appears grey when it must be green). Response: Plan view has been revised and profile view added to show proposed water main connection off Ruby Lane between Lots 3 and 4. Water main along Della Drive has been revised to limit the depth of water main lowering while not going any lower than the sanitary sewer main’s grade. MH 1 detail, please provide an example of the required detail. All utility crossings now shown on S&W and SS profile views. Sanitary sewer grades have been revised to at least 0.5%, as well as the appropriate material revisions due to constructability purposes and sewer depth. Nomenclature for “HBOE” (Hydrant Break-Off Elevation) has now been clarified and provided in the Sanitary Sewer & Watermain Construction Notes on Sheet 5 of the construction plan set. Sanitary and watermain (S&W) and storm sewer (SS) profile views are separate, we prefer to have as much SS left as grey in S&W profile views as possible to avoid colors taking over. Greyed out SS runs in S&W profiles are shown when running alongside the sanitary sewer runs with the appropriate SS and crossings as necessary. 52. On sheet 7 of 23: There is a yellow line identified in the plan view for Topaz Drive, clarify accordingly; it is unclear where hydrant assemblies transition from 8” water main to 6” in plan view, clarify accordingly; gate valves shall be installed north and west of the tee located at the intersection of Topaz Drive and Lucy Ridge Lane; update call-out in profile view of Topaz SP-10 Drive for the removal of plug and add removal of hydrant as well, for clarity; maintain ten foot separation between Block 4 Lot 7’s sanitary and water services and MH 9; update call-out in profile view of Lucy Ridge Lane where existing stub is located to “8” PVC SDR 26”, per as- builts. Response: Yellow line, centerline (CL), has been revised to no longer show as yellow in plan view for Topaz Drive. The 8x6 reducers will be installed 6-8 feet, prior to the hydrant. Appropriate gate valves have been added to water main near Topaz Drive and Lucy Ridge Lane intersection. Updated plan and profile view for water main connection west of Topaz Drive cul- de-sac. Sanitary sewer and water services for Lot 7 Block 4 have been revised to maintain 10’ of separation from MH 9. Revised profile view sanitary sewer connection along Lucy Ridge Lane to show as 8” SDR 26 per as-builts. 53. On sheet 8 of 23: Add note that trash guards are only to be installed on inlets or FES 24” or greater; castings on catch basins at low points shall be “VB”, update accordingly. Response: Added trash guard note under FES table, along with appropriate profile views as requested. Revised low point catch basin castings to VB accordingly. 54. On sheet 9 of 23: It is unclear what the low opening elevation is from the grading detail to the plans due to the use of double parentheses, e.g. when evaluating if lowest opening is 1 foot above emergency overflow on Block 3 Lot 4 the EOF elevation is 1013.0 adjacent to the lot while the call-out of ((1013.8)) appears to indicate the “adjacent grade to low opening” per grading plan, which is out of compliance, update plans accordingly and/or clarify; catch basin 7 needs to be relocated to a minimum of 10 feet away from the curb ramp; catch basin 12 and 13 shall be relocated to achieve a 90 degree connection; there is a portion of new impervious area on Lucy Ridge Lane that will not be captured by the proposed storm system, verify that the new impervious area will not inundate the existing storm sewer system north of Lucy Ridge Lane; Block 4 Lot 7’s backyard drainage sheet flows over the trail, no private drainage shall flow over the public trail system and needs to be accounted for in the storm plan (grading, back-yard storm conveyance, etc.); relocate CBMH 2 to the east in order to eliminate the double crossing of the public trail; relocate CBMH 10 to be centered on the property line (typ. of all backyard CBMHs); show all utility crossings on profiles (typ); add sufficient depth between CBMH 4 and CBMH 2 to decrease velocities below 12 fps, all RCP laid at slopes greater than 5% grade shall be tied; clearly illustrate where B6 curbing locations are for review and approval; add note that all FES shall have a witness post installed, the City will furnish witness posts; the outlet structure detail for Pond #2 shall be updated and drawn to reflect proper elevations (i.e. the outlet pipe is above the inlet pipe as drawn); add note to ensure outlet structures meet Detail Plate #3109A. Response: The holddown detail to call out grades. (SBI plans show BF = basement floor, the (xx) is 0.7’ below the basement floor,a dnt ((xx)), show the ground grade 10 feet outside of the back of the home. Catch basin 7 to remain as shown due to removal of pedestrian ramp/sidewalk along Topaz Drive, while catch basin 12 and 13 have been relocated to achieve a 90 degree connection. High point revisions made to be as north as possible on Lucy Ridge Lane, if this is does not suffice for the new impervious area not being captured by the proposed storm sewer, we will provide catch basins on north at connection, please advise. Lot 7 Block 4 rear yard drainage revised and now obtained by storm sewer system. Proposing CBMH 2 as shown due to grading constraints for trail. Proposing for CBMH 10 to be as shown due to grading constraints. Utility crossings now shown on all profile views, while revisions to storm sewer design have been made to decrease velocities to be below 12 fps. Added note to storm sewer construction notes and profile views where RCP grades are greater than 5% that all joints shall SP-11 be tied. Added notes to storm sewer construction plans that state B6 curbing locations for appropriate storm sewer structures, as well as indicated on the street plan sheets. Storm sewer construction note added that all FES structures shall have a witness post installed to be furnished by the City. Revisions to outlets structures have been made to show proper elevations with an additional note under the OCS table to meet Detail Plate #3109A. 55. On sheet 10 of 23: Update profile to ensure inverts connecting to in structures match crown elevations (HGL), typ; the RCP pipe between CBMH 20 and CMBH 19 shall be CL. 5. Response: Updated profiles where possible to match crowns, our only connection issue is at CBMH 19 from CBMH 20. Revised pipe between CBMH 20 and CBMH 19 to be Class 5. 56. On sheet 12 of 23: Profile from approximately 1+50 to 0+00 shows inadequate cover over 27” RCP pipe, adjust accordingly. Response: Grading plan has been revised to provide cover over 27” RCP pipe. 57. On sheet 13 of 23: The indentation and spacing of all notes shall be updated for clarity; note 2 discusses removal of sand/silt in ponds, a decompaction note must accompany this requirement as infiltration is a proposed surface water management technique; note 5 must reference the street detail and/or must be accompanied by a cross-section; note 6 shall be updated to allow for a minimum of 0.5% slope on driveways per Ordinance; notes referencing MnDOT seed numbers appear to be obsolete and shall be reviewed and updated accordingly; note 13 shall be updated from “the retaining walls” to “all retaining walls”; notes or the plan shall be updated to incorporate locations of bench marks, stockpiles, haul routes, staging areas, and dewatering plan, and typical lot benching detail; add note that all walls over 6’ in height require fencing or other barrier; adjust all retaining walls to be located wholy on private property and not City owned Outlots and/or wetland buffers. Response: Indentation has been revised with spacing to remain as is for clarity and sheet space. Note 2 decompaction note is addressed on the Erosion Control plan sheet 16, Item G. Note 5, 6 and 13 have been revised accordingly. Seed mix numbers need to be updated. Location of bench marks now shown on plans with lot benching details shown on grading plan sheet 13. Stockpile, haul routes and dewatering plan will be discussed at pre-con once contractors are established. Staging areas provided on erosion control. Additional retaining wall height/barrier requirement note has been added to the grading plan construction notes. Retaining walls have been adjusted to be within the proposed lots. 58. On sheet 14 of 23: swales between lots shall be graded to ensure drainage is routed along property lines and within drainage and utility easements, e.g. between Lots 3 and 4 of Block 2 drainage would be routed more or less onto Lot 4, adjust for all lots accordingly. Response: Swale has been redefined on the property line. 59. On sheet 16 of 23: The provided erosion control plan does not fully meet the requirements of Sec. 19-145 of City Ordinances, and shall be updated accordingly, furthermore no SWPPP has been provided meeting the requirements of NPDES General Construction Permit and shall be provided prior to the issuance of the Right to Proceed. Response: The SWPPP will be provided once we have a grading contractor. 60. On sheet 17 of 23: Details appear illegible or difficult to read as printed on full size plan sheets, the detail pages shall be updated to a maximum of 8 per page, or to achieve legible SP-12 details, for clarity. Response: Revised detail sheets to have a maximum of 8 per page. Stormwater Conditions & Wetlands 1. An NPDES permit and accompanying Stormwater Pollution Prevention Plan (SWPPP) will be required prior to the start of grading. Response: A SWPPP and a copy of the NPDES permit will be provided once we have a grading contractor, but prior to the pre-construction meeting. 2. Developer shall enter into an operations and maintenance plan for the proposed stormwater management system with Riley Purgatory Bluff Creek Watershed District prior to the City issuing a right to proceed. Response: Acknowledged. 3. All comments and conditions set forth by the Riley Purgatory Bluff Creek Watershed District shall be addressed by the Developer. Response: The comments have been addressed, and are back in for review with the watershed district. 4. Stormwater runoff shall not be discharged into wetlands without water quality pretreatment as prescribed by City Code. Response: Stormwater runoff is being captured and treated by ponding, or rear yard swales, prior to discharge into the wetlands. 5. Wetland Buffers. Wetland buffers and buffer monumentation will be required adjacent to the wetlands on site. Wetland buffer widths and locations where signage will be placed on a plan sheet must be identified in accordance with the City’s guidance document. The WMO provides signs and sign posts for the cost of materials. Alternative signs (by the City or Developer) are also acceptable provided they contain similar information. Wetland buffers and buffer setbacks pursuant to section 20-411 and consistent with the preliminary plat must be memorialized with a recorded wetland buffer agreement filed with the County recorder’s office. Response: We have shown the wetland buffer posts in the locations we feel are necessary. We did not put posts below the retaining walls, since this would be within the outlot area. If the City needs additional signs, please let us know. 6. It appears the Developer is showing contours within the filtration areas under the final surface elevation of the filtration areas. It is recommended the Developer callout the final surface elevation within the filtration areas and that the Developer add in cross sections (across the pond and filtration basins) to clarify the critical elevations within the basins. Response: Pond and filtration basins now provided with greater detailed information and cross sections on storm sewer plan sheets. 7. Developer shall confirm drainage from the hill west of the proposed home on Lot 1 along Della Drive is not being directed to the home, and shall adjust grading accordingly. Response: Revised grading plan contours to provide drainage swale around proposed home so that drainage from the hill is no longer directed towards the home. GC-13 8. Inlet protections are to be added to catch basins 6, 10, 11 and the catch basin to the west of the Topaz Drive cul-de-sac. Response: Inlet protection has been added to catch basins 6, 10, 11 and the catch basin to the west of the Topaz Drive cul-de-sac. 9. The Developer is using a constant 0.4 coefficient value for the rational method storm sewer calculations. Previous additions within the development used varying coefficients determined by the impervious/pervious percentages of each catch basin drainage area. The Developer shall either modify the storm sewer sizing calculations to use varying coefficients determined by the impervious/pervious percentages similar to how the previous storm sewer was sized or provide calculations demonstrating the use of a consistent 0.4 coefficient is valid. Response: The industry design standard range for residential single family lots is 0.3 to 0.5, typical design standard is 0.40. Attached is a sheet showing that 0.40 is a reasonable design standard. 10. The Developer shall update all storm sewer so the maximum pipe velocity is 12 fps. Response: Variety of minor revisions/additions made to storm sewer design to meet maximum pipe velocity of 12 fps as necessary. 11. The Stormwater Management Plan shall be updated to address the needs of additional volume for the future Galpin Boulevard Improvement Project outlined in Kimley-Horn’s memorandum dated May 29, 2018. Response: The plans and SWMP have been updated and are back at the watershed and City for additional review. 12. Developer is showing at catch basins 4, 18, and 19 the spread at the inlet will extend over 10 feet into the street. The Developer shall add additional catch basins at these points to reduce the spread into the roadway. Response: Additional catch basins added to storm sewer design to reduce gutter spread at catch basins 4, 18, and 19. 13. In the overall plans for the Park development dated 5/20/19 the proposed outlet for Wetland 2 was a 24” pipe but in the The Bluffs at Lake Lucy plans the outlet is an 18” pipe. It is noted that the existing outlet for Wetland 2 is an 18” CMP pipe. However, the HydroCAD modeling suggests the proposed 18” wetland outlet will cause an increase in the 100-year HWL within Wetland 2 when compared to overall development proposed conditions model and when compared to existing conditions (see table below). Developer shall confirm a larger outlet pipe is not needed and/or that the increase in the wetland HWL will not have any negative impacts on Galpin Avenue or any adjacent structures. Develoepr shall provide a larger outlet pipe if necessary. Response: Per the watershed district standards, the pipe size leaving wetland 2 has been modified to a 12” RCP to meet pre/post rates as well as existing/proposed HWL standards for wetlands. GC-14 14. In the Pond 1 OCS detail the outlet pipe is shown as an 18” but is being modeled as a 27” in the proposed HydroCAD model (assumed to be Device #1). Developer shall update the plan and/or HydroCAD model to be consistent with one another. Response: Proposed outlet pipe is a 27”. Plans/SWMP have been updated to match accordingly. 15. The HydroCAD model uses an exfiltration rate of 0.35 in/hr within Pond 1 but the stormwater narrative and the P8 model both have an infiltration rate of 0.8 in/hr. Developer shall confirm the appropriate infiltration rate and update all references to be consistent. Response: HydroCAD model has been updated to match updated design. Design infiltration rate has been based off of double-ring testing results. 16. The following updates to the P8 model need to be addressed: a. It is unclear why for both ponds a 12” orifice outlet is being used for the normal outlet directed to either the adjacent filtration or infiltration bench. Developer should change the normal outlet to a weir outlet based on the berm separating the pond and the infiltration/filtration bench or should provide reasoning behind using a 12” orifice. Response: Outlets for both ponds in P8 have been modified to match the current design. b. The flood pool elevations/volumes for Pond 1 and 2 should be calculated at 979 and 968 respectively based on the EOF elevations noted on the plans. Response: P8 parameters have been updated to match accordingly. c. The infiltration outlet for the Pond 2 filtration bench should be routed to the downstream waterbody instead of out of the system for accuracy. Similarly, in the P8 model where Pond 1 is being modeled as a filtration bench, the infiltration outlet should be routed to the downstream waterbody. Response: Design parameters have been updated accordingly. d. Developer should clarify what the wetland boundary infiltration device is that is being modeled in the proposed condition P8 models and confirm it should not also be included in the existing conditions P8 model for accuracy. Response: The wetland buffer represents the new buffer required to be created around the wetlands. It is included to represent the treatment being provided for areas of the site that are routed through the wetland buffer prior to discharging into the wetland. e. The bottom surface area for Pond 2 should be updated to 0.008 ac (or 0.01 if needed) to be representative of the plans Response: Value updated accordingly. Landscaping and Tree Preservation 1. The Developer shall conduct a walk-through of the grading limits on site prior to removals with City staff to inspect for opportunities for additional tree preservation. GC-15 Response: Acknowledged. 2. Tree preservation fencing shall be installed around existing trees to be saved prior to any construction activities and remain installed until completion. Response: Is tree fence required, or can we use the silt fence, as shown on the plans? 3. All trees shall be planted outside of the street right-of-way. Response: Acknowledged. 4. No tree Genus shall comprise of more than 20% of the total number of trees and no tree species shall comprise of more than 10% of the total number of trees. The Developer shall add 2 selections of trees to reduce maple quantities to meet ordinance requirements. Response: Will be addressed by the developer. 5. Developer shall provide tree preservation easements to be recorded with the final plat over Lots 1 and 2, Block 1 and Lots 1, 4 and 5, Block 3 as follows: easterly 300’ of Lot 1, Block 1, the westerly 200’ of Lot 2, Block 1, the northerly 100’ of Lots 4 and 5, Block 3 and the westerly 40’ of Lot 1, Block 3. Response: Please review the attached exhibit to ensure the areas we are preparing the tree preservation easements over is accurate and we will provide the necessary easements. 6. Park property boundary signs shall be installed at property corners on Lots 1-6, Block 4 and Lots 1-11, Block 2. Response: Acknowledged. 7. Landscaping shall be installed consistent with the approved landscape plan. Response: Acknowledged.