9620 19TH AVE SE 2018-01-02 MF Import

erosion control hydroseeding of the swale area, which is not ndvlE the specified seed mix. The attached detail showing the cross-section of the biofiltration/grass swale should be included on the storm V drainage plans and the landscape plans. The detail will help clarify swale construction. Piping Open ends of pipes 12" or greater should be equipped with , O trash racks. Miscellaneous: rn Gµ � The discharge location of root drains snouia oe snown co U K �11C ensure that roof runoff is routed to the detention system. The top and toe elevations of all rockeries adjacent to or associated with stormwater facilities must be given. The City is concerned about designing situations with water either flowing or standing near the base of rockeries and retaining walls. A sheet is attached that gives specifications for situations where rockeries and/or retaining walls are adjacent to surface ponds or vegetated swales. The appropriate detail should be given on the plans. !i It is important to leave enough horizontal room for \ construction of)the rockeries. City of Everett inspectors �• indicate that 4 feet is typically necessary. The plans need 1 to show this distance. -- salischarging to'an w_e d. The plans sh8w-the--i�iofiltrati.Ch.. ._ existing drainage course that is not adeq_uate to convey the flow from this site. The site drainage must be conveyed to the wetland system that exists to the west of this site. A completely tightlined system may be used or a ditch may be q)wconstructed with a catch basin and pipe outlet providing the final drop to the wetland. If the system must cross private property, an easement will be required. Appropriate energy dissipation will be required at the pipe outlet to prevent erosion. The outlet to the wetland must be constructed between June 15 and September 15, during dry weather only.