Assuming a non-COVID-19 scenario, where you were hired by City ABC to assist the City

Water Resources department in designing a groundwater aquifer recharge basin. Refer to

the schematic below.

Treated effluent from Wastewater Treatment Plant (WWTP) flows through a cylindrieal

pipe of diameter (d)=0.6m. This pipe is slanted at an angle 30° towards the end to allow it to

connect to a 2m x 6m closed top rectangular channel. After some distance, the rectangular

channel is open to the atmosphere (A2). The rectangular channel discharges water to a

4000 m² storage basin, 5m in depth. Water seeps in through this storage basin to the nearby

groundwater table at a rate of 10-5 m/sec to recharge the aquifer.

City ABC

WWTP

I AP

"d=0.6m

0=30

42

2m wide

6m deep

Recharge basin

A= 4000m²

h = 5m

a If for outdoor recreational water activities, the city wants to retain at least 80% of the

total recharge basin volume, what minimum discharge should the WWTP supply in

m³/s to result in 1m/year increase in the groundwater table of area 12000 m².

120/nb. Draw the velocity profiles at A1 and A2.

What are the velocities in the cylindrical pipe and rectangular channel?