Repeat Example 9-4 but with the following changes to the data:(a) SCS TR-20 methodology da...

Repeat Example 9-4 but with the following changes to the data:

(a) SCS TR-20 methodology data

(i) Existing (preproject) Tc = 1.3 hr; changed from 1.0 hr

(ii) Proposed (postproject) Tc = 0.4 hr; changed from 0.45 hr

(b) Figure E9-4(a) data

(i) Emergency spillway and basin design elevation = 229.50 ft; changed from 231.00 ft

(ii) Maximum basin depth = 14.0 ft (229.50 - 215.50); changed from 15.5 ft

All other data and information remain unchanged.