Looking for advice on budget friendly draining systems, not trying to spend a fortune. More so thinking about burying pipe with a valve. Water would be draining into another pond 35’ away. Then can easily pump water from a different spring fed pond on the other side to flood. Will be moving 3-5 million gallons.

Will be planning on doing this in the spring.

whats the water depth of the pond you are wanting to drain? If its relatively shallow, call seabreeze culverts in SE TX and see what dimension riser they can make for you that will stay put. If it's too deep for that, I would dig to the bottom and lay 2-4(depending on how fast you are trying to drain) 6 inch pvc pipe and put and threaded adapter with a plug on the outside, given that you are wanting to drain it completely when you do. Personally, I would stay away from valves. Sizeable valves are expensive and I've seen more of them seize up than stay functional. If you don't mind spending some money and want a legitimate setup, check out screw gates.

Siphon system

http://www.georgialandsales.com/pdf/PondSiphonSystem.pdf

Thank you for your recommendation, a little more info. Pond is 5 acres long, 1 acres wide. Average depth is 3.5-4 foot. Will be draining most, not all the water. Will leave an acre in the middle that will still have about 2 foot of water. Is 7’ there when full. Have already dug a hole in the dam, planted this year and back filled it last weekend. Will be digging the hole again next year to drain and lay pipe.

We stuck 4” pvc through our dam with threaded end caps on both ends.

personally, I've just capped the back side with threaded caps, I don't want to have to get that wet with a tool of some sort of it happens to be on there and the water comes up. They can make you a traditional flashboard riser that will work for you scenario I believe, but i'd call them and ask. That's a pretty big air bubble to be suspended in the water bolted to a flanged culvert. screw gate will also work but is kinda pricey, and of course, pvc pipe with a threaded cap. Not sure how fast you are wanting to be able to drain, but it takes a lot longer that you think to drain that kind of water through a 12-18" pipe. definitely go 6" if you go that route, and more than just one. personal preference

I thread both sides so nothing gets lodged in there. Mines 2 feet deep at the drain and the rest will dry out with a couple of weeks in the Texas sun

Plan on a 3-5 week drain between trips I can make there before planting. Any advice on getting rid of coontail and some other grass I have yet to identify?

if youre giving it that long to drain, the pvc route will be sufficient and the cheapest

get some pics of it if you can. there are chemicals to get rid of it, but theybasically block all the sunlight going through the water which isn't good for duck ponds, other than that, drain it. I would get a positive id if you can before you kill it, some of it may be more beneficial for ducks than you think, and its a lot easier to maintain.

What's the purpose of the ponds? Gadwalls LOVE coontail.

Originally they were zinc mine holes, now they are fishing ponds and we’ve been duck hunting the one the last couple of years as it seems to be the one the birds like the most. There isn’t a ton of coontail and I’m not as worried about it as I am the big grass mats. Whatever it is, it has basically taken over all 8 ponds on the property.

been thick during a season yet? ducks don't actually eat the coontail plant and hydrilla as well as they do the small seeds that wigeon grass produces. coontail and hydrilla will still house a lot of invertebrates, scuds, and snails though

The grass dies off and sinks in the winter, starts to grow again and takes over in late spring.

What are you calling wigeon grass? The only wigeon grass I know or have heard of grows in the brackish marsh and doesn't produce a seed...

its what youre talking about as well. it doesn't produce a "nut" or big seed like grain crops, but a small node type looking seed where the leaf comes off of the stem. It does this once a year, normally in the winter, late winter, or early spring.

If you want something that’s budget minded and will last get 6” Adrian 35 pipe from Act supply or similar. It’s about $20 for a 14’ pipe. Cap with schedule 40 6” pvc cap. I drill a 1/16” home through mine and run a piece of 10 guage wire with a handle for anything with pressure on it. I’m no expert but I did stay at a holiday inn last year.

Would that stuff be thick walled and strong enough to drive a truck over once 8-12” under the ground?