. Recorded flow rates for a net rain of 1.92 inches in 12 hours are shown in Table 3. If the base flow is 375 cfs throughout the storm, determine the 12-hr unit hydrograph, and convert it to a 6-hr unit hydrograph. Then apply the 6-hr unit hydrograph (UHG) to determine the total hydrograph (including 400 cfs base flow) for a 24-hr storm having four 6-hr blocks of net rain at rates of 0.7, 3.8, 10.8, and 1.8 in. per hour. [Hints: need to use "lagging method" as well as "S-UHG method"; Table 3 Time (hr) flow (cfs) Time (hr) flow (cfs) 42 1725 375 48 1250 6. 825 54 900 12 2200 650 3650 18 490 66 24 3900 72 410 3200 30 78 375 36 2375