HomeMy WebLinkAboutApplication Files_82693_pg0606 2. Compute the time of concentration(t,)based on the metliocLs described in Chapter 3 of TR-55.A
nainitnum value of 0,167 hour,,;(10 minutes)should be used. For sheet flow, the [low path should
not be longer than 300 feet.
3. Using the computed CN, t., and drainage area (A) in acres, compute the pesk discharge for the
water quality storm (i.e., the water quality flow(I&IQ.F1), based on the procedures described in
Chapter 4 of TR-55.
0 Read initial abstraction(IQ)from Table 4-1 in Chapter 4 of 77?-55(reproduced below);
compute 1,4/P
'Table 4-1 L values for runoff curve numbers
Curve• la -C&IL
la
.........
number 3n number 6YnUP , nnumbe..
r6
0 857 ::15: .35
55 .1,63� 30
6
86:;. 'A326
2 878 �;5 ....
...........
41 ..............
42 15W. 72 :�
-!7!.2
1448..�� 73 790 88 0273
44 2545 59
89 247-::
45 5 ���.166
2.4.44-1 1333
6 1,279 76 0 632 91 0198
97 �-2.255 62 1216 597 92 edp0174
—48 2l67 63;
9' .0532-- 941;....
V:
65
'
b7 4 985 82
0941 :133; .410 980091
0 Read the unit peals discharge(q,)from Exbibit 4-ffI in Chapter 4 of 7R-55(reproduced below)
for appropriate t,
(q Ex
pe I trib tion hibit 4 111 Unifbeak dischar2e r.) for N RCS (SCS) ty I I I ainfal di s u
.................
.....................---
P: .
..........
RGG
ggg
'J:rl A
A::�
:j ...........
4
�-J
.......... ...... .
L!
SG
J.]
...... ...
..........
..........
.................
............
�A
..............
Time of concentratio (T,),{hours]
2004 Connecticut Stormwater Quality Manual