Syphoning Down a Lake 1

[ChristopherFehr]

As part of our process I will have to reduce the level in a small lake that forms on top of our waste rock containment by about 1 meter. The average inflow is 900 US GPM and the water will only have to be piped a short distance overt he final spill way. How would I get the flow started? I assume I will have to run the discharge to a lower elevastion than the suction, just enough to cover the head loss in the pipe?

Some one over on the mechanical forum suggested the civil forum might be better for this one.

 

[GeoPaveTraffic]

You will need to put valves or plugs in each end of the pipe and a "T" section at the high point. Then fill the pipe using the "T", block off the "T", and open both valves at the same time. That should start the syphon. It may take a couple of times, but the keys are to get the pipe full and open the valves at the same time.

 

[Slugger926]

I have seen pumps used to get the flow going. Using valves, you can then let gravity take over the flow. I worked at a research lab that had 5 ciphens running over a dam that carried 30 CFM each. Geopave's method wouldn't require a pump, but some way of filling your ciphon up.

 

[MEM1]

We do this all the time do dewater ponds at feedyards. Use PVC pipe with a ball valve at the top. Plug your discharge end and hook you ball valve to the vacuum lines on your truck. Start the truck and let it suck the air out for you. Make sure you have a clear sight valve so you don't suck water into the trucks vacuum system. When water breaks the crest close the ball valve and off she goes by herself. You could then open the ball valve to let air in to stop the syphone.

 

[HughL]

Carefully immerse the pipe(s) in the lake so that it is filled with water as it is fed in. Seal/ plug one end and anchor the open end so that it remains immersed as you drag the sealed end to the outfall point. When all is set remove the plug.

regards Hugh