Pond Boss Forums INTRO Questions & Observations Overflow pipe?

Info: The pond is .25 acres. Only filled by rain water and some slope from back yard. Rains alot in winter not much in summer, Im in south La.

Well i had just fininshed my pond and had a couple of lil rains maybe a foot or 2 of water in pond. I figured i still had time to put in an overflow pipe. Well we just had a huge rain storm and it overflowed my pond in to my back yard! I couldnt believe it. There is no levee around the pond in my back yard so that water could drain from the back yard into the pond. So my quesion is whats a good size for an overflow pipe? 4"-6"12"??? The other problem is it has to drain into my side ditches which is just a hair lower than the current water level.
Thanks!

The people who respond will probably want to know specifics such as pond size (# acres filled by water), watershed size (# acres which drain into your pond), rainfall info, and probably some general description of surface of watershed (less might drain off disked field than an asphalt parking lot).

If there is any doubt go bigger! A 6 inch pipe should be sufficient but you really get some gulley washers down there so --- maybe 8 inch?

6 inch pipe is plenty for a 1/4 acre pond. The pitch flowing into your ditch is up to you. Just remember that if the outflow end is higher that will be the pond level. A 6 inch pipe can handle a lot of water if you are not on a stream and with your size. being a small pond.

Ok, took some elev.'s yesterday and looks like my pipe coming out into the drainage ditch will be under water. Will water still drain from the pond into the ditch even if the pipe is under water? The water elev. that i want is only 4" higher than the bottom of the drainage ditch! PLz post up any problems i may have or will this still be ok.

Thanks!!!!!!

be sure and get a pipe that is in a oval shape(i think this is the write word)it;s not comletely round,the bottom side is flat.this let's more water out than a round pipe.i have a 12" pipe on a 4 1/2 acre pond but it only gets about 1/2-3/4 full of water.next time i would use the above type pipe.

I haved kind of same situation and instead of a pipe I built a concrete overflow that is 4 ft wide and about 6 inches deep with a 2 inch berm in the middle. I have a piece of welded fence wire covered with mesh that sits in the area infront of the raised berm and keep the fish from heading down the drain. If you want a couple of pictures let me know. My pond is about 1/3 acre.

Jixxxer, as Brian wisely stated, the pond level will be governed by the level of the discharge. Let's say that you bury the drainline two feet deep, put an elbow at the discharge end and install a riser that is cut off four inches above the bottom of the ditch. That will be the level that your pond water will always return to. The pond level may be adjusted by increasing or decreasing the height of the riser. There will be outflow any time the pond water level is higher than end of the riser and higher than the level of the water in the ditch. When the water level in the ditch is higher than the pond level and higher than the riser, there will be backflow unless you install a check valve.
Water can be drawn from as deep as you like if you install a 45 degree fitting with an additional length of pipe. If you choose to draw water off the bottom, a "T" can be put at the end of the intake and stabilized with a length of pipe coming off each side of the "T". A screen made of 1/4 inch or 1/2 inch hardware cloth can be placed over the intake(s). At the discharge I would use window screen secured with a long hose clamp for easy removal and cleaning.
Perhaps you should consider improving your ditch or consider building an eighteen to twenty four inch high levee around the pond, which would allow you to lengthen the riser. Of course, with a levee, the drain field would be lost.
Since the carrying capacity of a pipe is directly proportional to the area of the its inside dimension, a round pipe will be just fine. Besides, although they may exist, I've never seen fittings that would accommodate a flattened pipe.