Working with an engineering firm on plans for a 22-24 acre pond that will incorporate an old 6 acre pond that was drained about 10 years ago. All the engineering plans call for a vertical stand pipe with a trash rack, but I am concerned with the need to add a structure over the standpipe to force water to be drawn from 4-6+ feet below the surface. The pond will be about 25 feet at the deepest point and a good deal of the area will be over 10 feet. I can't seem to find much online in products designed to extend down over a standpipe that deep or a trash rack that extends more than maybe 1 foot down. Any thoughts or suggestions on where to look for design plans or premade structures?

dhall,

Any impermeable structure you place over your standpipe, that ALSO extends above the surface of the water will only allow water to be drawn from the lower edge of that structure.

Imagine placing an 18" culvert over a 12" standpipe. Utilizing a 10' long culvert, that stuck up in the air by 2', the water draw would then be 8' below the surface of the pond.

If a rain event raised the water elevation of the pond by 1', then the water inside the 18" culvert would also go up by 1'. As it spilled into the standpipe, additional water would enter the 18" culvert from the bottom edge.

I hope that helps with the conceptual part.

However, that type of arrangement would restrict the water flow out of the standpipe. You definitely want your standpipe to flow at the designed capacity to avoid water reaching your emergency spillway whenever possible.

Maybe add a bottom water drain ahead of the main standpipe, or as a separate system?

Another option would be to add a bottom siphon system. Then you could easily control your water draws, and you would not be adding another pipe through the lower portion of your dam.

I have attached a link to an automatic siphon system that you can control from the surface.

Siphon Diagram

Good luck on your new pond/lake! Welcome to Pond Boss.

I believe I would add an emergency overflow at the dam. Just in case the main one stopped up.

How big does it need to be to be called a lake? Around here, 10 acres is called a lake.

If you own it, you can call it anything you like!!