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� y <br /> C�H . <br /> � Hw <br /> K�� . �`TTV �r � _^c....r, p•i_STTo DrTc��.r�OY r�,�^UT�=`.!=YTS � . <br /> �v~i� , mre sizing aE on-site detentions in t`:e Ci�� of c:erett is <br /> y y based on a 24 hour desic,z s�ors t�ical o: lor.y du:aticn <br /> ��d winter sto�s in �verett. For sites lerge: t:�aii 5.o ac_es, <br /> o��� on-site deteat:a;s systems vill be :;i�e� by Citj o� Everett <br /> nersonnel vit:� t::e use a- E?a's co�puter based sto�uater <br /> Q• aanagement nodel (Sn 2*) . A coey of the caapute.^. or:r.t�ut will <br /> �y� be provided to t'�e apnlicant at his/her :ecuest. <br /> H For sites s�zlle= than 5.0 acres, a se:ies of t:l�les shoc.-n <br /> gyH belo:r alloc: t:�e annlicant t� dete�i:.e his or her on-site <br /> C�y detent:on rect:irznent. These tables �:a=e develonec basad u�on <br /> a � a series o� cc��u�er siaulatians of stora::atzr ^�:oi= f=�� a <br /> 3�y hvcoc:�etical 20` ac=e dra=:tace basin. This 20 zc=e d:ainace <br /> - - bas�n incluZefl �an parcels varyinc in shzoe and s__e :rom o .25 <br /> ac:es to 5.0 ac�es. <br /> i:c:r �o use t'+e ''�O�eS' <br /> The first ste� is to. dete�ine t`�e desica stors c=i'teria for <br /> �e site in cues..=on. Tz�le 1 �hohs ::e desi_e.i st�� c�it=ria <br /> Por eicht c=zinzce basins/areas in Eve=e'=t. The loca�_ons of <br /> :.�'.E G:.21212G? b25:.'15 are S:lOw:1 1:1 i=�:== 1• <br /> ;,.`ter t.4e ces:ca stor� c__�e__a a=e �2=z'-�'-�•ea� �`e allewzble <br /> :fl_0252 T2�2 :O: �:0 OII-51�� ceteat_cr. SJS�T.2� 15 G2C==1:e+ �V <br /> usinc tables 1 .t:�ouch 4 . To use t�1=s '_ =`i==uch 4, t�e <br /> existirsg slcpe and cround cove= cancit'_ons o� �e sita in <br /> �1 cues�ian nee: to �e ceterined. � . <br /> ' ' The slone oE t:e sita aus� be cete�':e3 ::oa a t�pc�-anhical <br /> � - <br /> sur�ey o� t�e site or bv using :`.e C:ty's 1986 aera.al <br /> '�' tonog^�'anhical aaps. The sldne r=Pe'_'s to' .t-'�e slooe of overland <br /> flocr rat::er t'�an the slone oz t�e cha..ae1 or s:+a1< '�z� drains <br /> � f t:�e site. The exis�iny cround cover can be classiPied as <br /> � <br /> woods or Eores.e3; as laG�ns, c:ass o: landscapi.^.g7 as are <br /> '�1 " c��nacted ez�:� or czavel sur:.acec; cr zs a=� =�?e=�=OLS <br /> 1 f sur�ace. <br /> � <br /> :he Zinimu� size ori:ice zllawec for cn-sit=_ dPtea._oa sys..ems <br /> 1 is 2" . Assu�inc a borda . ori�ice (c�r.t=ac�ion coei:icient of <br /> ' 0.51) and a head o� t;:o Peet, t:e �in_�u� flow raca `.�=ough a <br /> � 2" oz'iPice is 0.1] cfs. Therefore, allocra'nle release rate.s of <br /> '�' less than .13 c�s should not be uszd to calcalate on-site <br /> detention recuireaents (see exaaole ;2 be7.o:+) • <br /> ��� <br /> 1_' • , . <br /> � -' . <br />