How do you compute required pump capacity

[Petersr]

My previous request was a little misleading. I would like to determine the required pumping capacity to handle the water created by a flood on an industrial building approximately 5000sf floor area, surrounded by earth with only driveways. The volumn of water is created by a storm 2 inches per hour. The soils are a mixture of gravel and clay. If you need to determine the permeability of the soil, how do you do that? Thanks for any help with that equation.

 

[dicksewerrat]

Well we will need a lot more data. How long is the storm? No water can escape? Total area of lot? Soil moisture? Total impervious area of lot?

 

[cvg]

what is volume of retention basin?
what is required time to drain the basin?
what is the acreage of the site?

ask your geotech to run a perc test to get an idea of the percolation rate in your soils

 

[boo1]

Sites listing Soil Percolation Rates and Percolation Tests is:

http://ianrpubs.unl.edu/wastemgt/g1472.htm

http://www.extension.umn.edu/distribution/naturalresources/DD0583.html

 

[gibfrog]

The best solution would be to RAISE your finished floor elevation. If this is not possible, then consider a pump. Remember, that the pump is most likely to fail when you need it the most due to a local electric power loss. Like winds knocking down poles or tree limbs knocking down wires.
The pump will need a an onsite generator backup and a spare cold unit standby, along with operation/maintenance personell.

As previously stated, much more data is needed to evaluate the pump. A 2"/hour rainfall event may not be very realistic. How critical is flood prevention? Is flood proofing possible?

Clifford H Laubstein
FL PE 58662