Pond Boss Forums POND CONSTRUCTION Building a dam Perfect Emergency Spillway??

What are some opinions on constructing the perfect emergency spillway? Would you use concrete, PVC, corrugated pipe....????
Imagine yourself at a 4 to 5 acre pond(hum that just happens to be the size of my pond oh well). Any Ideas welcome.

Hey Bulldog Fan. From your question it seems like you're asking about the primary spillway and not the emergency spillway. The "regular" spillway is usually pipe and drains off water under normal conditions and sets your normal full pond level.

The emergency spillway is usually just a lower area on the perimeter of the pond for times when the primary spillway can't handle the flow. It's always lower than the top of the dam to avoid having the excess water go over the dam.

I'm pretty sure that's right...

Well Kinda I am refering to the E-spillway, But i am afraid that it may get used more than normal. I have a 12" spillway (downpipe) that runs through dam. My pond construction was just complete about 2 months ago and has not filled up yet but I got a Laser Transit and "shot" the grade of my water level (where I am wanting the water to be) and for the water to be 6' at where I have built my dock it will put the water about 16" below to of dam. It is approx 4.5 acre pond. I am not sure that there will ever be a problem with it in the E-spillway, but I wanted to get some Ideas as to how to construct it. The contractor that built my dam (was in a natural valley so just had to dam up the stream that ran through it) put a 20'wide x 12"deep cut out on my dam that i was going to pour in concrete, but I am wanting to move the E-spillway off of dam so now I am looking for more ideas. I think I will have plenty of time it has been raining the past couple of weeks here and the pond has not came up much, it looks like it is only backing water up. I still don't have the whole bottom covered in water yet.

Sorry so longwinded

Bull frog, depending on your water shed Normally 16 inches is not near enough free board. the standard minimun is 3 ft from top of dam to E-spillway. The E-spillway should be as wide as you can make it if it's going to be grass. This spreads the water out and cuts down on erosion. Also allows for the mimnium free board.

i 'll agree with gw, i thinks he's right

i have a 5-7 acre pond with an 8 inch spillway drain pipe in the dam face. the builder left it several feet from the top . I extended it to within a foot of the top.

my emergency spillway is about a couiple inches higher than the tube , i have to really have a seriuos rain for the eway to see water 6-8 inches in 2 days will usuaslly do it

ive had the pond 2 years and the eway has seen water each year



i'm also the one who got sucked into the tube, do not try to extend the tube when the water is over the level of the pipe it is not safe!!!!!!!

Thanks I guess I shoulda made my signature name UGA FAN(Bull Frog???). Anyway thanks for the info. On another thread that I started "where to put overflow" Jersey said he had two 12" siphons on his dam I was thinking i may could construct something like this(maybe just one siphon) as well as my downpipe spillway and an E-spillway

Lots of good stuff. The spillway's job is to protect the dam.

It should let water out safely so the water will not go over the top of the dam and wash it out.

Grass, concrete, pipe will all work.

otto

There are also some really good geotextiles to reinforce the turf available. I think Brettski did a fair amount of research on this during his construction.

Contech Land Lok erosion control

Bulldog Fan,
If you haven't built your pond yet, I would tell you to seriously look into the siphon system. You don't need a siphon and a downpipe. The siphon sucks water off the bottom, which is a good thing. I also know a guy near you that I very highly recommend to build. Good price, great job. PM me if you are interested.

I like my siphon. I don't have aeration so at least I can move some of the bottom water out when it rains.

Really like the Geotextile ideas. Yes the pond is already dug but not full yet thanks for all the info. The siphon has to be put in when the dam is being constructed?