Outlet works for a detention basin is a spillway with a width (L) of 9.15 m (30.0 ft) wher...

Outlet works for a detention basin is a spillway with a width (L) of 9.15 m (30.0 ft) where the discharge is given by the weir equation.

The reservoir area is listed below.

Route the inflow hydrograph from Problem 6.1 through the detention basin termine the maximum discharge rate from the basin and the maximum water level in the basin. The starting water surface elevation in the basin is 152.4 m (500 ft).

Problem 6.1

The outlet works for a detention basin consists of two 1.22-m (48-in.) diameter concrete pipes (n = 0.013) 61.0 m (200 ft) long on a slope of 0.01. The entrance loss coefficient is 0.5 and the exit loss coefficient is 1.0. Assume the tailwater depth (yt) remains below the top of pipe for all discharge rates. The reservoir area is listed in the table below.

Route the following hydrograph through the detention basin and determine the peak discharge rate from the reservoir and the maximum water surface elevation in the reservoir. The detention basin is empty at the start of the storm.