Pond Boss
Posted By: bigfrog Stand Pipe and Overflow Pipe? - 08/31/05 02:35 PM
To Pond Pros and Mad Scientists alike,

I am so grateful for the information that is shared on this board. Not being a real pond pro, I do not post frequently, but enjoy this forum immensely.

Construction has begun on a new 2 acre pond, and I am looking forward to incorporating many of the ideas that I have gleaned from this board. I am fortunate to live in an area where the NRCS provides great service to those considering ponds on their sites. I involved them in two ponds a few years ago and was very pleased with the results. The first ponds and the new pond are watershed ponds and were created by building a dam across a draw in hilly land. The same engineer has designed this new pond as well.

In the earlier designs and in the new design, the ponds include a 6" through the dam overflow pipe with two anti-seep collars and trash guard. In addition, the ponds have 1 1/4" inside diameter perforated PVC stand pipes that have a shutoff valve on the outside of the dam for stock watering or draining water from the pond. In addition, there is an emergency spillway above the overflow pipe so that if the overflow pipe could not handle the outflow, then water could exit via the emergency spillway.

My question is this. Do I need the standpipe in addition to the overflow pipe and emergency spillway, or are there other ways to draw the water down if needed? The engineer says that this feature is optional, and they will approve the pond either with or without the stand pipe system.

I personally have not used the stand pipes at all on the other ponds and just wonder what the feeling of the folks here are on the necessity of these in addition to the overflow pipe. I am also wondering how well those PVC valves on the outside of the dam may function years down the road? (They are located in about a 6" PVC pipe sunk into the ground vertically, and you can turn them by using a "T" handle tool like you shut off a conventional water district line to a house with.) My NRCS engineer is non-committal on the need for a stand pipe. He indicates that they recommend them for being very useful were one to need to draw down the pond for mgmt purposes or for other reasons. On the flip side, he also stated that it is one more thing going through the levee and that if not properly installed can cause problems.

Maybe someone on this list that can speak to the necessity or value of the standpipe (when in addition to the overflow pipe and spillway) and their potential reliability years down the road. Or, are there other methods of drawing down a pond for mgmt purposes in the absence of the stand pipe that work as well.

Thanks!
Posted By: bigfrog Re: Stand Pipe and Overflow Pipe? - 08/31/05 02:39 PM
Upon re-reading my post (and I did preview it first too), I realized I probably did not make something clear. I realize the function of the stand pipe, emergency spillway, and the overflow pipe are very different. I mentioned the overflow pipe and spillway only because I thought that might be relevant regarding alternate ways to draw down the pond in the absence of the stand pipe. Sorry for leaving that out.
Posted By: Dave Davidson Re: Stand Pipe and Overflow Pipe? - 08/31/05 02:53 PM
I agree with the NRCS guy. No way I would poke a hole in the bottom of the dam. You can always use a siphon system to draw down the water.
Posted By: Theo Gallus Re: Stand Pipe and Overflow Pipe? - 08/31/05 03:08 PM
Stock watering can also be done less drastically. I have a 1" plastic water line buried below the frost line around the end of the dam. We put 2 anti-seep collars on it. The top end runs into the pond to a filter suspended about 2' below the surface (supposedly, the cleanest water in the pond is below surface plants/plankton and above bottom muck). The bottom of the line ends at a freeze-out hydrant where I water the cattle.
Posted By: Meadowlark Re: Stand Pipe and Overflow Pipe? - 08/31/05 03:11 PM
bigfrog,

As a mad scientist who has built two ponds and has two others under care, I would never use anything through the dam for drainage, overflow, etc. only as a last resort.

Natural spillways cost far less, will never leak or clog up like pipes, will never rust or otherwise decay, and require very little to no maintenace. I have ponds as old as 75 years with natural spillways that have never been even maintained...cows keep the growth in check.

There are certainly situations where a drainpipe may be required due to unavailablilty of a suitable location for a natural spillway...but IMHO, folks are far too quick to routinely recommend those through the dam drains when natural spillways are readily available.

As Dave said, you can use siphon systems to drain if that becomes necessary.
Posted By: Alligator Re: Stand Pipe and Overflow Pipe? - 08/31/05 07:20 PM
Could you use a syphon design instead of the overflow pipe? There would be no need for a stand pipe...unless I am missing something here. Lots of ponds in East Texas use Spillway only design (no built in way to drain - but hey how many times do you actually NEED to drain). I have both spillway and syphon. Either way, Emergency Spillway = good idea.

Gator
Posted By: Ric Swaim Re: Stand Pipe and Overflow Pipe? - 09/01/05 01:07 AM
Looks like I'm in the minority here.
Most ponds around here have stand pipes. If installed correctly & you have good clay soil there shouldn't be a problem. I checked around before I built my new dam for references & pond owners here don't even know what an antiseep collar is. I guess it's this red clay, it compacts like a rock.
My small pond had a stand pipe that rusted & fell. The pipe thru the dam clogged & the pond refilled. All this before I bought the place 19 years ago.
I used a siphon to drain the pond last year & it wasn't easy. After 3 tries with the sipnon stopping and then using a pump I finally got it drained & had to hurry to unstop the original pipe so it wouldn't refill. (There's a good spring feeding)
When I built the dam for my new pond I put in a drain pipe so I would never have to go through that again.
Just thought you ought to hear a different view.
Mike Otto had a piece in Pond Boss mag about pipes through dams.
Posted By: Theo Gallus Re: Stand Pipe and Overflow Pipe? - 09/01/05 01:28 AM
I'm sure the utility AND viability of stand pipes varies considerably depending on climate and soil types.
Posted By: Dave Davidson Re: Stand Pipe and Overflow Pipe? - 09/01/05 11:37 AM
Ric, an anti-seep collar is a piece of sheet metal. About 4'x4'with a hole through the middle to accomodate the, through the dam, drain pipe.
Posted By: Matt Clark Re: Stand Pipe and Overflow Pipe? - 09/01/05 03:43 PM
Ric:

I'm in that minority along with you. I have a water line through the dam. It will (if needed) be used to water livestock and consists of a 300' stretch of 1.25 inch black poly, high-pressure water line, connected to a frost free hydrant below the damn, with a shut-off buried 4 feet down and a t-handle valve.

We installed a 24" square anti-seep 1/3 of the way between the damn and the hydrant. That would be the one (and only) weak point in this system. The anti-seep is galvanized (but it's double dipped and quite stout). I suppose it's subject to rot, but it'll outlast me, I'm sure. Inlet side is same 1.25" poly, in a "pigtail" formation with holes drilled along it's length.

I've drawn water a few times from it to haul fish in a tank to the pond. Spose I could use it to drain pond, but it's only about 2/3 of the way to the bottom...
Posted By: Theo Gallus Re: Stand Pipe and Overflow Pipe? - 09/01/05 06:49 PM
You guys have anti-seep collars quite different than the ones I used on my drain line and water line. They are 4'x4' rubber sheets you staple to a wooden frame and cut a hole through the middle for the pipe. Then place the pipe with the collars in the trench and backfill and compact.
Posted By: Dave Davidson Re: Stand Pipe and Overflow Pipe? - 09/01/05 07:10 PM
Theo, with wood, seems like it would rot.
Posted By: bigfrog Re: Stand Pipe and Overflow Pipe? - 09/01/05 08:50 PM
Thanks to everyone for the quick responses to my question. I feel much better making a decision about this and intend to discuss it with my contractor further now that I am aware of some of the pros and cons. In the specifications, it does not call for anti-seep collars on the PVC stand pipe system, just on the 6" overflow pipe. Unless they have a good idea for fabricating one like the rubber one Theo mentioned, I may opt for the increased trouble of working around not having a stand pipe, since my needs to use one have been non-existent thus far. Although it does sound like they provide a nice system if and when they are needed. I am still curious if anyone can address failures with the valves? I guess it could be that they likely outlive the installer so no one has had any problems with these yet.

Thanks again for all the insight.
Posted By: Theo Gallus Re: Stand Pipe and Overflow Pipe? - 09/01/05 11:05 PM
DD said:
 Quote:
Theo, with wood, seems like it would rot.
The wood frame will certainly rot; it's only purpose is to hold the rubber sheet in place until you get the clay compacted on both sides of the collar. Then the soil is supposed to hold the collar in place.

That's the theory. I'm certain the wood is gone now (soft pine after 4 years) and the dam does not leak at either pipe. But I'm not about to dig it up to check the collars. ;\)

bigfrog:

The collars we used were a standard item from the local discount drainage supply place, where we got our pipe and drain box.
Posted By: Alligator Re: Stand Pipe and Overflow Pipe? - 09/02/05 02:33 AM
Ok, I have been pondering this stand-pipe thingie (oh geeze watchout) and I dont understand the intention of the standpipe design. Granted, I had a stand pipe, so I am not knocking what works. It works. But why would you NEED a stand pipe. What does it's design provide that a drain pipe does not provide?

I keep thinking about "why would you put a hole in the bottom of your dam" - there must be a good reason. What is it?


Posted By: Ric Swaim Re: Stand Pipe and Overflow Pipe? - 09/02/05 11:40 PM
The hole in the bottom of the dam is to drain the pond.
The stand pipe is to maintain water level at the top of the pipe. The stand pipe can be sleaved so it will draw deeper water & not loose the top fertile water if you wish. It is also less susceptable to beavers clogging with a sleave.

A siphon can be used in the same manner & if the inlet is positioned correctly will drain most of the water from a pond when needed.

When I was siphoning my small pond I toyed with the idea of a cheap foot valve. The most econimacal idea I came up with was an innertube clamped to the outside of the pipe inlet & then pushed up inside the pipe inlet. Water could enter the inlet but hopefully the innertube would collapse preventing it's exit. It would have to be long enough as not to be pushed back out the pipe when filling it from the top of the dam. This was the hardest problem to overcome when the siphon quit & the water level was down 10 ft. I had the pond drained before I thought of it though.

Some sort of strainer should be used on the inlet of a siphon to prevent fish, turtles ect from clogging. I think that's what happened to mine.
Posted By: Alligator Re: Stand Pipe and Overflow Pipe? - 09/03/05 01:18 AM
Ric,

Put another way, what is the benefit of a stand pipe over a common drain pipe?

gator
Posted By: ewest Re: Stand Pipe and Overflow Pipe? - 09/03/05 01:21 AM
Ric :

Good points. We use a 5 gal bucket with holes drilled in it over inlet end of pipe for small pipe. Have to make sure it does not deter inflow to much or siphon will stop. We use chain link fence material to make a guard for larger pipe. We have stand pipes on 2 ponds one with a siphon also and one with just a siphon. You have to be careful about bottom valves. The one we had was hard to open even though it was a very good quality one. The reason we found out later was because at that depth the water pressure on the face of the plate was to high to turn the release wheel. One thing we use is a balloon valve . Just insert and inflate. ewest
Posted By: Ric Swaim Re: Stand Pipe and Overflow Pipe? - 09/03/05 12:12 PM
Thanks ewest, I like the idea of a ballon valve. Where a source?

Alligator, not sure what you refer to as a "common drain pipe" but I put a drain pipe in my new pond. No stand pipe just a drain. Valve is on the outlet.
Stand pipes usually have a T at the bottom with a valve for draining in the horizontal (open to the pond) with the other horizontal end connected to the pipe thru the dam. The vertical opening of the T is where the stand pipe goes.
The benifit? As you can see the stand pipe will maintain water level in the pond & allow draining or lowering water level. The drain pipe can't be used for maintaining water level.
Posted By: Alligator Re: Stand Pipe and Overflow Pipe? - 09/03/05 12:29 PM
Ric,

Thanks for clearing up bigfrogs question for me. Raising and lowering - yes, that IS a big advantage.

I assumed most stand pipes did not have drain value (mine didnt) and couldnt figure out why go to all of that trouble to build a stand pipe when a simple overflow pipe would do the same thing.

I get it now thanks.

The puzzleing thing is why build a stand pipe without a drain valve...go figure.

BigFrog,

I would like to revise my comments.

Stand Pipe with drain valve = good.

or

Syphon System = good.

Spillway good.

Not sure why you would need a overflow pipe in addition to one of the above. I suppose a good overflow pipe woudnt hurt, but a spillway does the same.

I cant speak to the maintenance issues with the valves - I think Ric and others addressed that. I can say that my stand pipe rotted and drained my lake. Like Ric, I filled in the "hole in the bottom of my dam" and went back with a Syphon design.

I am biased against holes in the dam since I had trouble with mine, others have not had any issues.

Gator
Posted By: ewest Re: Stand Pipe and Overflow Pipe? - 09/03/05 01:31 PM
Ric and Gator :

We have one stand/drain pipe like Ric described with valve at bottom. Valve is to hard to open. Wish the valve was at outlet as Ric describes. We put a siphon that goes down into pond with a u joint over the edege of stand pipe and down into stand pipe with valve at bottom of siphon inside stand pipe. It has a short piece of pipe that stands up at top of u joint with a cap. That is where you fill up with water then just pull the long handle attached to valve and it works like a charm. It is a 6 in. pvc pipe and takes about 15 gals of water to start. So one advantage of a stand pipe is you can add a siphon to it if you want and you don't have to go over or through dam again. Ric we got the balloon valve at a plumbing/water supply store -- no big deal to them they were suprised we didn't know about them. ewest
Posted By: Alligator Re: Stand Pipe and Overflow Pipe? - 09/03/05 01:49 PM
ewest,

I like the siphon inside the stand pipe idea, thats a good one!

Gator
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