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

� ��11 �i,il�i �,�� `i� � .1 �� I. � , , � �...�t .�l CC \l(!It itl..� r�C�Ci,rs,.l�(. � , ) �t n� � ��'',�, !'�fn�U �u.(' Ci:��ry��15 rfl �ll�f �j �.I�`ri� n�.s �tti . i 1 CJ _ M E M O R A N D U M TO: FROM: DATE: BUBJECT: I/I �'' � Gordon Witcher 4�,n � ��,Q �' Jane Zimmerman L � � ��e� �� May 19, 1993 f Plan Review �2, SEPA 92-89, Casner Creek Townhouses I have the following comments after reviewing the subject plans: CALCULATIONS Basin hvdroloq}� The submitted calculations show a reduction in the size of basin C, which contains a wetland alonq the south edge of the site. The resultinq diversion of runoff away from the wetland may adversely affect the wetland's hydrology. Per the SEPA requirements, "Develonment of the site must not adversely affect the hydrology of the site's wetlands. It is important that the hydroperiod for the wetlands not be altered to the point that major species changes will occur. The quantity and rate of water entering the wetlands must be det�rmined for current condition. Under develo�ed conditions, a similar rate and quantity of roof drainage or treated runoPf must continue to be discharqed to the wetland(s). Calculations showinq the inflow and outfluw durinq a normal rainfall year relative to existing and post construction conditions must be provided. Prior to anplication for buildinq permits and plan review by the Public works Department, a characterization of the hydrology of the wetlands on or adjacent to this project that may be affected by the development of this site must be reviewed and approved by the Planning Department." Detention• The configuration of the detention pond, k�ith the non- permeable berm between the two cells, will result in dead � storage in the first cell of the pond. Therefore, not all of the volume of the first cell will be available for live storage durinq storms. This fact must be accounted for in