1600 121ST ST SE 2016-01-01 MF Import

A planting schedule for the treatment area of the wetpond muat be approved by the City. The plans should call out the type of vegetation to ae planted, the density of the plantings� and the total number of plants needed. Plants suited to the depth of water in the ellowmirisarand/orould be used, such as hardstem bulrush, y cattails. Required density of plantings is a minimum of one per square foot (1.0' O.C.) in the Silver Lake drainage basin, or one per 2.25 square feet (1.5' O.C.) outside of plantedVin groupsrrather thanninWatcompletelyfrand mame type pattern. The pond detail must clearly show tne arra of the pond to be planted and a note ahould referen�:e the plantii�g schedule. The actual contours for the pond and how they relate to the surrounding topography must be s;hown. Per City standards, if the side slopes of the wetpond will be greater than 3:1 (H:V) retai.�inq walls must be provided. Rockeries are generally not allowed in association with wetponds. Pipes in wetpond areas must ha•✓e sufficient cover to allow for future sediment removal w:thout damage to the pipe. A minimum of 2 feet of cover, both horizontally and vertically, is required. The inlet and uutlet structures to the wetpond must be designed so that all stormflow is forced to travel the full lenqth of the wetpond. If any berms are to be constructed as part of the wetpond design, the following note regarding pond berm materials on the plans must be included on the plans: NOTE: Berm soils shall consist of material conforminq to the following gradation: Sieve Size 3" ,� 4 �'200 � Passinq 100 65-90 12-20 The following notes regarding construction of the wetpond treatment cell, and the topsoil specification, must be included in a conspicuous place on both the storm drainaqe plans and the landscape plans: