09/10/2014 P&Z Packet - Laserfiche WebLink

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Ms. Katie Larsen September 4, 2014 Page 2 ■ Revise the curve numbers based on RCWD Rule C values (HSG B is 61 for existing pervious areas). ■ Please include the 7.2-inch 100-year 10-day snowmelt event to determine critical water surface elevation. ■ Ponds PDI and PD2 do not have an outlet, how will water drain from the ponds? 2. Grading and Erosion Control Plan ■ There are two ponds labeled as P 1 ■ Label pond types (ex. detention basin, infiltration basin ,etc) ■ Unable to determine if freeboard requirements have been met without more information on the types of ponds being proposed. ■ Pond outlet structures as specified in the HydroCAD model not shown on plan, nor do the elevations match the plans, please clarify ■ Do not see erosion control features on plan, please verify ■ High water level for the pond in catchments P4 and P5 do not match HydroCAD results (906.69, and 906.88, respectively) ■ Pond 3 normal water level is below the pond bottom elevation Post -Development Drainage Plan: ■ There are two ponds labeled as P 1 ■ Label pond types (ex. detention basin, infiltration basin ,etc) ■ Pond outlet structures as specified in the HydroCAD model not shown on plan, nor do the elevations match the plans, please clarify ■ High water level for the pond in catchments P4 and P5 do not match HydroCAD results (906.69, and 906.88, respectively) ■ Pond 3 normal water level is below the pond bottom elevation 4. Administrative: ■ The applicant must provide an operation and maintenance agreement for stormwater facilities. This agreement must be recorded against the parcel so that it transfers with future sales of the parcel. This may be included as a part of the Developer's agreement with the City. ■ The applicant must receive permits from other agencies prior to construction. Permits needed may include the MPCA's NPDES Construction Stormwater Permit and RCWD's Stormwater Management and Erosion Control permits. Grading Comments: Benchmark or datum not shown on grading plan, please specify NGVD29 or NAVD88 for the vertical datum. Utility Plan: 1. Label exiting utilities (8" PVC sanitary, 8" DIP watermain. 2. The east sanitary MH in Arlo Ln is mislabeled. 3. Provide a detail of the proposed pump station. This concludes our plan review comments at this time. If you, or the applicant, have any questions regarding these comments, please contact me at (612) 360-1298 or dhankee@wsbeng.com.