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<br />STOAM ORAIN STORl16E REQUI REMENTS , ��� �� � �^ S �' ?
<br />,, �
<br />� ,c�.�� Y � ,s�t�� ,.
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<br />� � � c � � l,
<br />A■ �p acres �'"��� � Are� of B�sin
<br />C ■ Q I p ,� 5� Existing coeffic.ient of imperviousness of
<br />� ' Bas1n ground
<br />cd = c' S3
<br />L. ■ %SO feet
<br />s
<br />Yr
<br />T�
<br />- 3. 3 x
<br />_- � ��� �'.i �,�r; �
<br />�- Q, ft/sec.
<br />� �� minutes
<br />I � ��( in/hr.
<br />��
<br />/�; ��'.
<br />Qe � �, q Z, cfs
<br />Qa = p, Ig cfs
<br />T� ` `�7 /o
<br />�s s Z��'C�
<br />Developed coefficient of imperviousness of
<br />Sasin as planned
<br />Length (maximum) of' overland travel
<br />Slope averagej from Basin high polnt to low
<br />point on watercoursel
<br />Runoff rate
<br />�
<br />Time of concentration from fo►mula:
<br />10 +(L t Yr (60)) � T�= l0+05560� _.� �� :�, Sti
<br />Rainfali intensity fran r,+i�fall curve
<br />(10-year storm)
<br />Existing outflrn,+ from site using equation: �
<br />C�I�� • Qe=0IG�0.96�iZ0 ��,�r i�, �i'�' 11 ���� r,
<br />�' -
<br />Maximum outflow permltted peo• acre �,qz
<br />imperviousness fram formula: ,Qo � Qe = ACd =`�(;53;
<br />minutes Storage time (to capacity) frmn formula:
<br />i= � �2706 _ ZS = �17, E•
<br />Y . I F�
<br />cf/A/Cd Required volume of storage per ai:re in Basin
<br />from equaiion: �� 4�29 97.t _
<br />S 4o(q�,b)(:i�)
<br />Izz,G
<br />yt = Zci�Og( cubic feet
<br />l �
<br />Ur�.jl<< ., ,�
<br />( �r �Cc, Ir�•(;��., � ��
<br />I�vr,� �/o�„M� P�.,,��
<br />^ 34
<br />1 97
<br />Requlred volume of storage for thi.s Basin fram
<br />equation: �t . ysACd =2744iZo�•s3
<br />F3N��cz�,4 =�u,.i33��(g8x��+'/z(��)�q�)�-Yz��s,(-v.'%
<br />_ �� � FG�r� jC -�rr Ccn'��',-.,,., �.
<br />AVE�. Ikl%fH �[}-� �`' 2�` �� ��`J��eC '� � I
<br />lo,�� v�..v�-,.� = 44, Gs6 Fp3 p�;,•,I�
<br />S�a*Ti��cr 2.ar�P = %z C'��i4•g��C�s� = 108�� � ' ;I
<br />�.1�T i1�,_ �-�_ = 4�, s�� r-, 3�
<br />
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