2017-03-28_PWETCPacket - Laserfiche WebLink

Home

14. Aprons or flared -end sections shall be placed at all locations where the storm sewer outlets a ponding area. All outlet flared -end sections above the NWL of the pond shall be furnished with hot dipped galvanized trash guards. All trash guard installations will be subject to approval by the City Engineer. 15. Riprap and filter blanket shall be placed at all outlet flared -end sections. The placement of the riprap shall be hand placed. The minimum class of riprap shall be MnDOT 3601.2 Class III. Design criteria justifying the size and amount of riprap are required. Geotextile material is not allowed for filter aggregate where ice action along the shoreline may tear the geotextile (see Detail Plate). 16. The invert elevations of the pond inlet flared -end sections shall match the NWL of the pond. Submerged outlets will only be allowed with the use of an outlet structure (see Detail Plate). 17. Long radius bends may be used for grater than 24" pipe diameter if necessary and approved by the City Engineer in vertical and horizontal alignment. However, only one series of bends will be allowed, either vertical or horizontal, between structures. 18. If the public storm sewer is to be installed less than 10' deep within private property, the easement shall be a minimum of 20' wide with the pipe centered in the easement. If the storm sewer is 10' deep or greater, then the easement shall be twice as wide as the depth or as required by the City. 19. Show or define access routes for maintenance purposes to all manholes outside the public right-of-way and inlets or outlets at ponding areas (8% maximum grade, 2% cross slope, and 10' wide). Access easements shall be dedicated at the time of final platting to provide this access. 20. Junction manholes should be designed to limit the hydraulic head increase by matching hydraulic flow lines and by providing smooth transition angles. 21. In the development of any subdivision or ponding area, the Developer and/or property owner is responsible for the removal of all significant vegetation (trees, stumps, brush, debris, etc.) from any and all areas which would be inundated by the designated controlled NWL of any required ponding easement as well as the removal of all dead trees, vegetation, etc. to the HWL of the pond. 22. The Developer and/or Engineer upon the completion of the construction of a designated ponding area is required to submit an as -built record plan of the ponding area certifying that the pond constructed meets all design parameters as set forth in the City's respective stormwater management plans. 23. Utilization of existing wetlands for stormwater management is subject to review by the appropriate regulatory agency in accordance with the "Wetlands Conservation Act". 24. Outlet control structures from ponding areas are required as directed by the City. Location and appearance of outlet structures shall be subject to City approval and