Hello - I have a 2.5 acre pond that sits at the bottom of a valley. It is spring fed and typically stays around the same level, unless we have a very long summer drought. The main source of water bubbles up out of the ground about 1000 feet from the pond and trickles down a creek bed into the pond. There is another inlet that catches alot of run off, but a very high water table. In this area and in one spot near the main creekbed the water bubbles out of the ground just from driving a mower over it.
Where the main creek bed feeds into the pond, I get sand / sediment build up creating a sand bar. I just had the pond dregged and removed a lot of water shield and muck / built up sediment and quite a large sand bar. There is a link below tgat contains a video which should give you a pretty good idea of my issue. About 3 years ago watershield totally took over the pond. In the video when I pan out to show the pond, that used to be completely covered in watershield. The remaining watershield you see is where the excavator couldnt reach. The watershield was so thick that as the sediment rushed into the water it hit a wall of weeds and the sediment just built up there. I thought that dredging and removing the watershield would solve this issue. Last night we had our first massive rain since the pond was worked on and now the problem is back.
When we get these heavy rains the water just RUSHES down the creekbed (normally it is a trickle). This time I could see alot of the sediment disperse into the water, but it still made this sandbar. How can I prevent this sand bar from forming? I just built a land bridge over the creek and I'm going to add a bunch of rip rap near the pipe inlet and outlet, and a few other places above and below the pipe to prevent washout and also slow the water. Will the rip rap help by slowing the water down? Would love to know if anyone else has had this issue of sediment build up and how to prevent it.
I should also note that I have a pond siphon overflow which i've been having trouble with. I've attached a picture for reference (but not sure it will work so here's a video https://www.dropbox.com/scl/fi/ytc5...4av69wabzskita8&st=xi71tav2&dl=0 ) . In the picture the highlighted circle shows what I will refer to a water level control pipe. My pipe is 2 inches in diameter and originally extended about 3 feet under water at about a 45 degree angle. It has several holes drilled into it. The siphon is supposed to break once the water level hits one of these holes. It doesn't stop on mine until the water gets all the way to the end of water level control pipe. Incredibly frustrating as we'll get heavy rains at night, and then I wake up and my pond is drained. I drilled a bunch more holes into the pipe; it didn't break siphon. I cut the end of the pipe off so that the water level wouldn't get so low, and then drilled even more holes. It didn't work, but now it stops pumping at a level i can live with. Perhaps this fix is for another thread, but i thought i should mention this because in my mind, if the water is pumped out faster than its coming in, then at some point the sedimentary water will start to build up at the inlet because the water has become shallow there and it doesn't have as much depth to disperse. Is my logic sound?
If there is room on the property, dig a sediment pond before the main pond where the creek flows into the main pond. The water velocity will slow down, the sediment will drop out there and enter the main pond. Plan on cleaning out the sediment pond annually. That's really the only fix to the problem.
