8204 SPOKANE DR 2016-01-01 MF Import

puecic woRnrs TO: FROM: DATE: SUBJECT: Wgtpond/Detention• MEMORANDUM Kirk Brooks Jane Zimmerman May 3, 1995 Drainage Calculation Review, Broadway South Condominiums The stage-storage relationship of the pond is required to show thatthe pond has the capacity to store the required wetpond permanent storage volume and any live detention volmne. WY1-(kmc� Routing of the�design storm developed hydrograph through the pond is required to verify that the entire wetpond design volume is reached during the design storm. The size of the primary orifice can be decreased as necessary, to a minimum allowable orifice size of 1 inch, to back up enough live storage. If a 1 inch orifice dcesn't result in the required storage in the pond, then the percentage of the wetpond design volume provided as dead storage must be increased until the combination of dead storage and peak live storage equals the wetpond design volume, cl�r� n:� •+t.� we ti-pc,�,d c�es�yn 51uri�, wh;d„s �+t,e lp rrwrH., , Z4 -h� 51-c rrn . The control structure must ensure that d�e detention release rate dces not exceed the allowable release rate aIId that the detained volume in the pond reaches or exceeds the wetpond design volume for the design storm. OriMce si�in�v: Non-publicly maintained restrictor devices may have a minimum orifice � ze of ] inch for both detention systems and wetponds. The orifice size calculated on sheet 3 of 5 appears to be inconect. 1l�issslleueullS: Calculations must be submitted for the downstream drainage system. Per City standards, the system should be designed for a� year srorm. io - - : =_..� �-�, . _._...