Pond Boss Forums POND CONSTRUCTION Building a dam Spillway help

I am in the middle of building a 7-acre, 37-acre-feet (according to NRCS) pond in SW Oklahoma. The NRCS has designed a simple overflow spillway pipe, but I would very much like to install an overflow that drains from near the bottom as described in the Ray Scott video. It seems to make good sense, but I have been unable to find any plans or even descriptions. Can anyone give me a lead as to design, materials, costs, and experience with such a spillway? Many thanks, Tom Pool

Canepole, if your spillway pipe is like a pipe that sticks out of the surface of the water, perpendicular to the water surface, then all you have to do is take a pipe (PVC) of larger diameter, and "sleeve" it over the actual stand pipe. Make sure the outer pipe is taller by a few feet than the original spillway pipe. The outer pipe should be at lease several inches greater in diameter than the original pipe.

Then you can take a metal shaft (like a dowell rod) and stick it through the outer pipe to serve as a stop to support the outer pipe; the rod will rest accross the top of the original pipe.

The outer pipe should be several feet higher than the original pipe at whatever your comfort level is for high water.

I may be over simplifying this.

I'm sure someone else will chime in.

Sunil, I think I get it. Very simple, and there is still time to alter my set-up. Clearly the outer, larger pipe must end at some distance above the bottom of the pond, and this pond is quite deep at the dam (estimated 38'). What distance is recommended for a new pond? Thank you very much for the quick reply. Tom Pool

Tom, I'm really out of my element on this one, so I can't recommend how far off the pond bottom you would want to be with the outer pipe.

The reason I knew about that method of using an outer pipe is because it was discussed on this forum maybe 6-12 months back.

Your posting is fairly new, so as the day goes on, others will give valid input.

By the way, your project sounds great. That's really deep at 38'.

Good luck.

Sunil, I know it is really too deep to be useful, but that is just the lay of the land. To get the acreage I desired and access to the watershed required (we don't get enough rainfall in SW Oklahoma) I had to build a high dam to extend the pond laterally sufficiently. Sadly, I am posted in Guam and have to enjoy the building of this pond vicariously through my brother and nephew. It has been my dream since adolescence and I'm missing the best of it. Thanks again for the help. Give me five years then come fish it with me. Regards, Tom

Tom,
Scroll down the topics and you will see many posts regarding spillway systems.
You may want to take a look a siphon system with an emergency spillway.

By the way, when I “visited” Saipan and Guam many moons ago, we fished at low tide with hand grenades....

When you look out over the blue Pacific in the direction of Oklahoma dream BIG – mine came true...

Good luck,

George Glazener
N.E. Texas ¼ acre and 2 acre ponds

Tom, OK, five years it is then.

While the overall depth of 38' may be unusable for most fish, others here have done nice things with making islands and humps on the bottoms of deeper areas that will come up to more shallow depths. These become fish attracting areas.

I think another benefit is that all the earth does not have to be "removed," just moved into piles. This benefit has been stated by others.

There might be some kinds of desireable fish that could utilize that deeper water.

Wow, that's a big pond Canepole! :p The green is for "envy".

One way is to run the overflow pipe through the dam, then elbow it straight down close to the bottom of the pond.

The pipe must run through the dam at the maximum water level you want. A small vent pipe MUST be tapped into the main horizontal pipe, sticking straight up. The vent pipe should be taller than the water should ever reach, and have a tee on top with hardware cloth to prevent critters from blocking it.

Leaks that follow the overflow pipe are not a big worry with this type of overflow.

Thanks, everyone for all the information. I wish that I had known about this forum months ago. But it is not too late to be helpful. I just found out last night that the pipe is already through the damn. It's galvanized (wish I had known to insist on PVC) and runs straight through the dam and nearly parallel to the water surface at maximum desired water level. Bobad, your suggestion should be entirely possible, although it would have been much easier to fabricate if the pipe had been PVC. I had not considered that it might not be smart to move deeper water in the middle of winter. Will have to research that.

To maximize water that is roughly 6' deep, I have carved out the sides of the pond. I am a little worried about controlling erosion at the relatively steep edge. Is there a preferred groundcover that might help hold these edges.

Below the surface, these shelves extend out a ways ending at a ledge adjacent to much deeper water. That was my understanding of the recommendations to create ambush points for the bass. I will add structure to the edges of that shelf and plan to use the 5-gallon concrete bucket anchored to angle iron system. Does anyone have other recommendations or "artificial" structure? Again, I am very grateful for the assistance. Tom

Canepole not sure if this is what you were talking about but hope it helps.
http://muextension.missouri.edu/explore/agguides/agengin/g01531.htm

Tom,

Two that have worked very well for me are 1) common bermuda and 2) pensacola bahia grass.

I have no idea what your climate is like or if you have access to these seeds. The bermuda works well and is very pleasing around the pond. The bahia really thrives on hot weather and humid conditions, and will not tolerate cold. It sends down a very large root system, tubers, which make it very good for erosion control. It is also somewhat invasive as it readily spreads in favorable conditions.

JBL, that is a GREAT website. Thanks very much! Meadowlark, I think our winters are too cold for the bahia. I am beind advised to plant "switch grass" around the emergency spillway and rye to hold the ground over the winter on the dam and exposed sides of the pond, and then plant bermuda as you suggested in the spring.

I have another question: In carving out the sides of the pond to increase the amount of 6'-8' water, what should I do with that earth? I can move it towards the belly of the pond to increase the width of that shelf, or I could remove it from the pond entirely. As we all fight silting in, it seems a shame to move any more earth into the belly of the pond, but I am not sure if having a wider shelf would actually increase the productivity of the pond, or only increase the number of ambush opportunities for the bass. I hope this makes sone, and I hope someone has some insight. Many thanks, Tom Pool

Tom,

If I understand your situation correctly, a good use of that material would be to build several submerged "islands" in that real deep portion of the pond. Build the islands well up above where the thermocline will run and then add some permanent structure on it to top out just below the surface. I did this in a 4 acre pond with 25 foot depths. I wanted to make use of some of that "bad" water area in the deep portions and make it an asset rather than a liability for fish. It has worked really well. Those "islands" have turned out to be real fish magnets. It's relatively easy to build them, especially since you are moving the dirt anyway.

Regarding the rye grass, you probably know that you need to seed it really heavy for erosion control. It has a thin blade and tiny root system and it takes a lot of seed to hold soil. One thing that has worked for me it to use old hay spread around over the exposed surface area. It gives good protection, decomposes into good soil builder, and can provide a lot of grass seeds as a free benefit. I've used the big round bales for that purpose and just unrolled them over the exposed areas. Really stops erosion, but you need a tractor to handle them.

p.s. I thought you were in Guam, but see your pond is an Okie...yes bahia probably would not survive your winters.

Meadowlark, that's good advice about the round bales and the rye. I will do as you suggest. My bulldozer man has built a lot of ponds and seems very devoted to the success of this project. This is the first of three ponds I plan to build on 500 acres that I purchased just for that purpose. It is practically against his religion to push dirt into the middle of a pond. We are still studying it. Thanks again for your timely assistance.

Pushing dirt back into the area where you removed dirt does seem counter-productive. I'm not talking about huge areas, however, just small islands. Ours were probably 15 to 20 feet in diameter and we used the track-hoe to build dirt up. It works, but does seem odd.

Meadowlark, I need some further advice about the roundbales. We have completed the earth work on the pond and I need to cover the exposed areas quickly before rain can make a mess of it. How did you secure the unrolled bales to the sides of the dam and other steep inclines? Is it necessary to do so? How long will the hay hold up before disintegration? Will it have to be removed before planting the eventual cover grass?

On a different issue, the bulldozer man felt it was too late to create a hump in the middle of this deep pond. I do not want to have catfish in this pond. What other species might make use of this deep water? I have caught crappie in deep water, but the references seem to recommend perch as the bass forage fish of choice. Is there a problem with crappie? What are the implications associated with more artificial structure, like an old automobile body or two? Would the engine and trans need to be removed or is thorough draining adequate?

Last, the excavation at the deepest part of the pond exposed a spring. Can this or should this be exposed further? It seems unlikely to me that the spring would overcome the pressure head caused by more than 30-feet of overhead water, but my training is medical and not fluid dynamics. Thanks again for any suggestions. Regards, Tom

Tom, I'm sure ML will comment soon on the bale thing.

Regarding you hitting a spring, from what I've read here on the forum, it may not be good news. A lot of the members have experience with that.
You may want to create a new topic in this general category, maybe under "Selecting a Site" or "Soil," or maybe a new thread in this sub-category to make sure you get some pertinent answers.

As far as artificial structure, my pond is 6-7 acres, and everytime I feel I've done a lot of structure placement, I know I should do more. People do use old cars, but I don't know the procedures; I would guess you would remove anything containing hyrdrocarbons, or remnants of hydrocarbons. Two or three cars would be good, but ten to fifteen would be better.

Tom, I would personally cover the spring ASAP. I just spent 4 hours today hauling clay to dump in a small pond that has a spring. I think another 10 hours of tractor work might do it. And, it might not. About 5 years ago, I used a backhoe to clean it out. I thought it would be a year round source of water. Instead, it sucks all of the water that runs in. Springs are aquifers that can take as well as give.

That's great information, all. It makes perfect sense too. Should have realized it. I need to get it covered soon before it fills with water. Thank you very much for the information. Best regards, Tom

Tom,

Spent the weekend on a dozer clearing ground for another new pond...so couldn't respond until now.

Round bales: Here's what I do. Place them on top of the dam and unroll them sideways and down across the backside. Gravity will help move them along once you get it started unrolling. I like to go sideways because that way you get more coverage without having to pick it up and move it back on top again...don't get in front of it once it gets up a head of steam.

By spring it will be pretty well decayed, but if you want you can simply burn off the remaining. I like it because it adds humus to your soil as it decays and in most clay dams that's needed to get a good seedbed. It will sure stop erosion if you get the surfaces covered well.

Regarding your "spring"...as Dave mentioned, really look carefully at this. Since it is in your deep water, without question, I would cover it with 2 feet of well packed clay. If left uncovered, your spring very likely, when the pond fills, reverse direction and become a leak. Maybe it won't but since it is in the deep water, with the highest pressure, I would not take a chance on it and cover it up with good clay.

Meadowlark, I think that is great advice about the clay, and there seems to be a good bit in the soil there. I would not have added so much as two feet, so I am glad that you added that dimension. Perhaps I can make my "hump" in the bottom of the pond after all in effort to cap this spring. Or, since it is a relatively small area, so you think bentonite would be a surer fix? I wish I could show you a picture, but it does not seem that I can attach a file to this forum.

Thanks also for the explanation on the round bales. Makes sense. I'm trying to make as few mistakes as possible on this pond as I plan to build two more that will be somewhat larger. I learned today that I had the wrong information on the size. NRCS says it will hold 49.7 acre feet of water and cover 7 acres. The bulldozer man says it will be larger still because he extended it laterally somewhat beyond the original planned boundaries and added two terraces to increase runoff capture from adjacent hills. The dam looks HUGE. It's going to be tough to manage the round bales going down much of a grade at all. Thanks again for the good info. Regards, Tom

Tom, you've got to get some pictures posted.

One of the first steps is to sign up for one of the "free" accounts with someone like PhotoBucket or OPhoto, and upload the photos there.

Once that's done, the procedure is fairly simple to do.

Tom,

Clay packed at 2 feet is far superior to bentonite. If it's good clay, 100% sure it will not leak when packed properly.....like I said, don't get on the front side of those round bales when they start unrolling!

Sounds like a great place.

Sunil, Meadowlark, thanks again for the information. I created the Photobucket account as suggested. Here is the URL:
http://photobucket.com/albums/d114/speardeep/

I hope this makes it a little clearer. You can see the overflow pipe that will have to be reworked to draw water from near bottom of pond. I was too late learning about the concept. Don't be misled by the cut boundary just opposite the dam. That is not the pond edge. All of that grass will be under water, quite a lot of water. We tried to disturb as little ground as possible. If you see anything that needs to be changed and that I can still change, please don't be shy. We plan to build two more ponds on the same property that will be somewhat larger. I am a lot smarter than I was two weeks ago, but I still feel that my Fingerling title is a bit generous. Thanks again, Tom

Canepole, word of advise,if you decide to put old cars in your pond as Sunil has suggested, be sure to remove the door & window handles. I have heard stories of people that have hooked record size fish but could not get them in because they would get hung up, It was latter found out that the fish were simply getting in the cars and rolling up the windows.

Seriously how big is your water shed to feed this 7 acre lake. I am just curious because I am currently working on the design of approximately a 4 acre lake(want be near that deep) but the fill area looks much like your pond site.