Pond Boss Forums POND CONSTRUCTION Building a dam Drainpipe Riser emergency overflow dam heights????

First off next week I have a contractor coming out to do some renovating. Fixing some old wind damage wash out and muskrat damage..

Here's my main question though.. I'm thinking of welding a riser on my drain pipe hoping to raise my pond a couple feet so I'll have more capacity in times of drought like this.. What's the risk? I'm thinking the main risk would be actually raising the water level above the pipe.. Also I have a really thick damm all clay so I'm not to worried about water traveling around the pipe down.. Also if Anybodys done this I'd love to hear your story and opinion and possibly see some pics of your setup.. what could be done to make this work the best and be leakproof,? weld some kind if collar before the 90° riser then completely burry it all in clay.. Gimme some ideas guys I wanna do something while I can with the pond down 3'.. Thanks for the help guys

BGK

I have done this very thing...when I bought the place i have now there was a pond on it...a long dammed up creek that runs through the timber...I bought an elbow (not 90 degrees) and put it on the existing tube. Bought a five gallon bucket of tar roof sealer, put it all around the existing tube..a LOT of it...filled in the ridges completely and then used enough to add a couple inches of thickness all the way around it. Then did the same thing to the new piece I was adding. Used a lockdown collar and joined the pieces together. Next I boxed in the tube with railroad ties and packed it with clay to cover the joint...added some rock on top to keep the clay there when the water is high. This has worked great...raised the water level almost 2 feet. The only concern you might have is the increased water pressure on your dam..but I doubt that is an issue..I have pics but I can't seem to upload them...I can email them to you if you like

I pm'd you thanks for the info.. My pipe is thick wall steel so I'm thinking just weld the 90° and a riser on it..

Anyone else done something like this?? What's your results?

We have done this one several ponds. We are happy with the results on each pond. One pond took a 72" riser. Feel free to PM me if you need more information.

I made my riser for my dam drain.. I planned on putting it in this weekend but 6+" of rain changed my plans.. Took some pics of the riser couldn't get a full 90° elbow so I'll have to 45 the drain pipe to get it standing straight up.. Also i made an end to maybe keep vortex to a minimum, don't know if it'll work but it just slides off and on (with hammer treatment ) what's you guys opinions..

BGK,

That is really cool! I wish I knew how to weld. It would come in handy for some invention ideas I've had!

I assume you'll paint it before installing?

Yeah i have some good epoxy paint we use on oil stock tanks that'll I'll slather on it.. After it's welded on..

Good deal. Impressive!

Looking good! What's it weigh? It's hard to tell from the pictures, but I'm guessing 3/16" or 1/4" for the anti-vortex and 3/8" or 1/2" for the pipe?

1/4" on the vortex (diamond plate) 1/2" thick for the piping.. Probably about 75 lbs

BGK, Nice beefy addition. What is the orange inside the pipe? Is it a screen? If it is a screen, are you worrried that it would plug?

No the kids put their basketball in there..

I think I'm gonna have to pump the pond down to get it welded on.. I have a couple questions if I don't get much response through this thread I'll make a more specific thread for them..

Anyways.. First how much dam height is recommended to be above your water level.. And also how much emergency spillway height should be below your Sam height.. Hope that makes sense..

Maybe we can get 100 miles of hose and pump it into my pond. I only came up about 8" last weekend. Hoping tomorrow dumps more.

I am by no means qualified to answer this question. However, I will use my farm/common sense to give my thoughts. Somebody who knows about these things will need alot more info about the scenario.

Have you ever had the outflow pipe not handle all the water and it started to back up into the pond, increasing the water level? If so, how much did it rise? How many years have you had the pond to gauge this? If you ever had the water level come up to start using the emergency spillway, raising the pipe seems like you will use that spillway more.

The emergency spillway is just that. You never wnat to use it, but......... it's there for the very rare case. Maybe once every 100 years? I would think that if you satrt using that emergency spillway frequently, it should be in very good shape or disaster may follow.

I don't think the emergency overflow has ever been used.. But the water level does back up over the pipe (not efficient setup).. I'd say the emergency overflow is 4' above the pipe and the dam is 3' above the emergency overflow.. The riser will add about 30" of water when full. Is there any kind of standard for height of dam above pipe and same with emergency overflow..

I changed the title to be a little more specific.. Sorry for any confusion..

So after adding the pipe, it will force the water to be 6" from using the spillway on a regular basis. You said that your size of pipe does not always handle the amount of watershed coming into the pond. So it stands to reason that the spillway WILL be used, possibly frequently. You have to determine if you really want to do that.

A few other questions that may help others to tell you more
-- Even if you are 6" from the spillway, will the water have an additional place to flood to (like lots of acres) instead of going over the spillway?
-- Will the water level even come up to the top of the new pipe and STAY there? If it never does because of insufficient watershed, this gives you a bit of an area similar to what I just asked about areas it can flood to.

If I have been following the posts correctly, you just went thru the rains from the hurricane and it brought your pond up 3'. If you put this riser on, and that happens again, what then? Seems like you are in jeopardy of that happening every year because of your location. If it was me, I would be leaning towards building the dam and the spillway higher.

I don't think anyone will be able to give you a formula that fits all ponds. To many variables for every pond. It's the famous "IT DEPENDS".

I think my dam is high enough but my spillway might need raised.. All my measurements so far are just by eye I'm taking all the measurements this weekend with a transit..

As far as my pipe draining now when it was built the put a cover on it closing the top third of the pipe I have no idea why maybe has to do with vortexong but seems very inefficient at draining.. I have plenty of watershed to fill it and plenty of room for the extra water.. Basically just from eyeing it I'm gonna have to raise my emergency overflow but I need to know how much difference is recommended between it and dam. Also when have a major drought I'm hoping it will only lower to the current full level..

Just my 2 cents wort here...I would consider the width at the top of the dam as well...there will be more pressure from the extra water being held back, not sure how much topsoil you have on the top of the clay on your dam, but it could turn to mush if the water gets above the clay layer into the topsoil. Is vortexing a bad thing? Does it slow water going through? And with your anti-vortex device, will this create 4 mini vortexes (or perhaps vortices?). My tube does it when the water gets above the tube

I would tend to agree. The percentage that your spillway should be raised is more than the percentage that the dam is raised....Only a speculation on my part.




My thought on this is that they wanted to keep the water in your pond for awhile. It would be a form of controlled flood protection down river from you. It would also let the pond have a "flow thru" for a longer period of time. Isn't it a good thing to keep the water flowing for the health of a pond, even if it is flowing out and not in?

Here's a couple pics I think have more than enough dan Amrit it's like everything else around my property it's probably solid clay.. First pic is from the side looking toward the father in laws house.. Second pic is from the opposite side.. Other pics are just kinda randoms of the dan area..

The ground can look different than it actually is. I would wait for the transit measurements this weekend.

Yeah and the pictures make everything look messed up