Percolation and evaporation losses

[mayor610]

Dear ALL,

We in Chhattisgarh are in the process of designing Sewerage Master Plan by proposing to trap the DWF flowing in nullahs through a weir and diverting it the proposed STP d/s through intercepting sewer which is also proposed to be laid along the river.

The point is ---since all the existing nullahs are unlined , is it correct to presume PERCOLATION LOSSES as 20 % with only 2 % evaporation losses.
Terrain consists mainly of quartz mica schist & quartzite with granite gnesis intruded by granite & dolerite.

Regards,

Mayor610

 

[cvg]

you need to conduct percolation tests to determine percolation rates. evaporation is time dependent and is a function of surface area, wind, humidity, air and water temperature. you will need to estimate loss rates on your parameters