Originally Posted by

**nogoodnamesleft** Hi there all you clever folks .....I'm having a problem with my local council regarding flooding, basically they are trying to palm me off with some bs "solution" that I know by common sense, will be completely innefective ...unfortunately, I'm useless at maths, so I'm unable to work this out myself ....would one of you kind people help me out with a calculation please ?

During the flooding, the water remains "standing" at the same depth for some hours...I have calculated the volume of the "standing" water to be 140m3 (although, that's probably irrelevant) ...there are 2 x 6inch diameter drainage pipes at the bottom of this "tank" draining this water out.

For the purpose of this equation, we can assume that the pipes draining the water away are running full bore at 100%, completely unhindered.

What I need to know is......

1) what is the flow rate of the incoming water (bearing in mind it's keeping the "standing" water at the same depth, as it's being drained by the two 6 inch pipes) ?

2) what diameter of drainage pipe would be required at the bottom of the "tank" to keep it empty in the first place ?

Please dont be concerned with all the potential things that could cause the answer to vary ......I just need a reasonably calculated answer on a simple in/out basis !!!

I hope its possible to work that out ....maybe I've just made you laugh ??

It would be really helpful, if I could find that out, so - thanks in advance