Laserfiche WebLink
, � . <br /> . A . <br /> • <br /> Reid, Middleton � Associat�s, Inc. �` <br /> FL.F N0. 02-85-094 Engineers • Surveyors • Pionne+s i <br /> October 10, 1985 � <br /> Revised Oct. 25, 1985 <br /> S`lORM WATER DETFN'PION CAI.QJLA'FIQNS FOR <br /> SII,VER I.� SELF SERVICE S10RPGE APID CAib+]ASEi <br /> BY HIGEr WEST ODREORATIOd� <br /> C727 OF �I�.E7IT� WAS�HII7Q10N <br /> Area = 3.197 Acres ' �.�� <br /> Residential lot with grasa field and woodc.�d azeas west of residence �� G � <br /> Existing runoff coefficient = (SEE P�TA� CI�I,C. S'FIEET AAID PIAN <br /> 7t� = 450/1(60) + 10 min. = 17.5 min. ,,� � y <br /> �tensity = i = 1.38 in/hr @ 10 ,Yr. Stocm EVerett Curve � � ,� � <br /> Q existing = c i A =� ( 1.38 ) 3.197 =�9� c.f.s. <br /> � 2• , � �{'r. <br /> , ; <br /> , <br /> Area = 3.197 Acres � <br /> Prorated runoff coefficient = SEE A7TA�lID CALC. SHE�T = 0.82 �`j3 <br /> Design Stocm = 25 year � � ' � .a ` <br /> Required Detention = Qo ='0.97/ 0.82(3.2) = 0.35 i._,1 -�j�j+�} �" ?� a:- �' . <br /> �_.. . <br /> T = -25 = 2706/0.35 =.b2A3 l,- � �j �f <br /> Vs = (4329(62.93))/(62.93 +25)-(40(035)62.93 <br /> = 3098.19 - 881,02 = 2217.17 �i . � � "�-';=, .�ji�j <br /> V total = 2217.17 (0.82) 3.2 = 5,817.85 Cu.ft. �'(� '. �'' '��i��"� <br /> Due to the lack of a def3ned storm drainage channel to the south of this <br /> project artd after a meeting with Dan Mathias, City of E�ecett. 7i�is project <br /> will discharge it's s�ocm water into the existing drainage way at the norkhwest <br /> corner of the project and contribute to the regional etoLm water detentien <br /> systan fund for said basin. �e contribution will be based on a cu.ft. charge <br /> of $2.37 for the required detention volimie Eor this project; - <br /> = 5817.85 X 2.37 = $13,788.30 . ! / <br /> -., l <br /> � +.- � r � if ��+ c'1 , <br /> � �, , , , t <br /> �-�'t ;',_ � � � <br /> ��- � ` ` � � <br /> ! <br /> 121 S�h Avenue North, Suir_ 200, Edmonds, Washinqton 98020 (206) 775-�4�4 <br /> : <br />