Need help rehabbing a pond

Mudfarmer · Jul 1, 2011

Need advice: I recently bought 40 acres of timberland outside of Elma in Western Washington. Most of it has recently been logged and replanted, but there is one area with about twenty year old trees covering about four acres of realatively falt ground at the bottom of a draw. There is a small creek running through that area. By small I mean about a foot across and 6 inches deep. I assumed it was rain run off and would dry up in the late summer but am now not so sure of that. It may actually be a year round spring. In any event there is a pond covering about a half acre in the midst of the four acres with obvious beaver activity (read mess) at the down flow end of the pond. So my wife and I assumed it was a beaver pond. We set out last week to break the dam to decrease the mosquitoes in the area. About a foot below mud and beaver sticks we ran into a gravel berm. My first thoughts were that those were some pretty industrious beavers. I got tired of digging at the gravel by hand after about half an hour and left the wife digging away to check out a smaller pond below the main one. It had an obvious beaver dam that I was able to dig out with a shovel. The little pond drained over the next half hour revealing a 12 inch concrete pipe at the base of the gravel berm (read dam) that was flowing about the same amount of water that the creek was delivering to the top of the pond. Best I can figure is that this was a pond built 50 + years ago to provide water for forest fire control. As far as I can find out no one has ever lived on the property. Next thinkgwas to poke a 20 foot pole up the pipe - did hit some obstruction at the full length of the pole which would have been well on the pond side of the gravel dam. I presume the pond was constructed with this pipe as a drain and that the inlet on the upside is mostly obstructed by debris, silt, beaver junk or a cap. Hence my question - any great ideas about how to clean this pipe out and make the pond drainable and functional again. I would like to drain it and clean out the silt. Any experience with how such a pond might have been designed and how to (cheaply) clear the pipe would be appreciated. I will remember to take my camera on my next project day.

Mf

bones66 · Jul 2, 2011

Several years ago I cleaned out a pipe under my road that I was going to replace because it was stopped up tight! An an old timer told me what he had done to unstop pipes in situations like mine so I tried it and it saved me Big Time. As I stated I had a culvert pipe under an old road that had gotten stopped up with many years of mud and silt and small sticks. I took a gas water pump and a long enough discharge hose to reach through the pipe. Fixed a little bit of a reducer on the discharge end to act as a venturi. Not much just wanted some power to hit the muck with rather than a lazy discharge! I put the hose into the end of the culvert pipe. The end that would have been the discharge end had it not been stopped up. Insert the hose as far up into the pipe as possible and start the pump. I used my pump hose with my venturi as a battering ram hitting the muck and blasting while I kept pushing as much hose into the culvert as I could. I'm sure by now you get the procedure. I wasn't clear if you can get to the lower end of the pipe or not. Good Luck!

MarkV · Jul 2, 2011

I would think it more common that the pipe have an elbow at the end with a stand pipe set at a height that determines the depth of the pond. If the pipe just went straight through it would be a culvert and the pond would drain.

It isn't too hard to make a siphon out of PVC to drain the pond. A google search should get you some descriptions.

MarkV

bones66 · Jul 2, 2011

MarkV said:
I would think it more common that the pipe have an elbow at the end with a stand pipe set at a height that determines the depth of the pond. If the pipe just went straight through it would be a culvert and the pond would drain.

It isn't too hard to make a siphon out of PVC to drain the pond. A google search should get you some descriptions.

MarkV

I was having a little trouble figuring out just what was going on by the description. If the upper end of the pipe was above the normal water level then it would act as an overflow and only run when the water level was higher than normal, thus the beaver wouldn't like that sound at all!

Mudfarmer · Jul 4, 2011

Thanks for the advice. My thoughts were that there is likely an elbow as well, however I have seen a pond set up with a board that obstructed a straight pipe. Using a pump with venturi device is a thought. I worked on a county road crew when I was a college student and spent a lot of time on the back end of such a device cleaning culverts. Not sure it would make a 90 degree elbow-bend though. By ther way those county nozzles swivelled, having one jet forward and three jets backwards - like to pull you of your feet as it jetted into the pipe. I will check around with rental outfits. I like the siphon idea - I have some PVC pipe sitting around. How do you get the siphon going on one or two inch pipe - don't think my lungs are up to that.

Mf