Laserfiche WebLink
Mr. David Hempel <br />July 31, 2017 <br />Page 2 <br />Grading, Drainage, and Erosion Control Plan <br />6. Provide additional drainage/utility easements to accommodate proposed drainage swales; <br />a. Lots 1-3 Block 1 <br />b. Lots 1-2 Block 2 <br />7. Provide a drainage easement for the Fable Road North EOF located on Lot 5 of Block 4. <br />8. Provide the natural EOF elevation for Lot 4 of Block 1. Verify if compliant with adjacent low floor <br />elevation. <br />9. The City requires 3 feet of freeboard between the lowest building opening and the 100 -year HWL. <br />The City/Watershed District requires 2 feet of freeboard between the lowest building floor <br />elevation and the 100 -year HWL. Provide the HWL for the previously constructed pond (Outlot A), <br />and ensure freeboard requirements are met for all adjacent lots in Block 3. <br />Street Profiles / Details <br />10. Design vertical curves to meet 30 mph design speed for stopping sight distance. Specifically, <br />confirm that the sag curve at station 28 on Fable Road North meets the design speed <br />requirements. <br />11. Curb type shall be the Modified S design shown on the Hugo detail. <br />Stormwater Management <br />12. Label the location and provide the invert of the Filtration Pond outlet pipe on the plans. What <br />happens to the outlet flow at this location? The City owns the adjacent land to the east, and there <br />is an existing trail near the property line (running N -S along Clearwater Creek) that is currently <br />being inundated by runoff from this existing basin. The City will require that discharge from the <br />Filtration Pond outlet pipe does not flow overland across the trail. A culvert crossing may be <br />necessary to correct this problem. <br />13. Provide a detail of the revised Filtration Basin's outlet control structure. <br />14. Clarify the function of Device #6 in Pond 10P: Revised Pond with Filtration in the HydroCAD <br />model. What happens at the weir elevation of 922.50? The plans show the riprap overflow at <br />923.50. <br />15. Time of concentrations typically include a maximum limit of 150' for sheet flow. Generally, runoff <br />becomes concentrated after this distance, and should be modeled as shallow concentrated flow. <br />Revise the following time of concentrations in the HydroCAD model to reflect this limit: <br />a. Existing Subcatchment 8S <br />b. Existing Subcatchment 10S <br />c. Proposed Subcatchment 9S <br />Wetlands <br />16. Provide an electronic shapefile to confirm the most recent wetland delineation. <br />17. No wetland impacts are proposed as part of the Phase 4 improvements. <br />We will continue to work with the developer to address technical design and other minor issues related to <br />the project as the project moves forward. <br />Thank you for the opportunity to provide comments on this project. If you have questions, please do not <br />hesitate to contact me at 651-286-8463. <br />K:1D19047801Admin\D-1LTR-d hempel-FableHiNth PP 07 31 17.docx <br />