We have a 3.4 acre pond in Virginia. It had a 12" standpipe with a mushroom cap, leading to a 15 inch culvert through the core of the dam. It worked well for 50 years.
Last summer we grouted the old culvert (it was rotting away) and installed two 18 inch culverts - layed in horizontally, with no standpipe. The culvert inlets are covered with rebar grates (about 3 inches OC). We thought we had plenty of excess flow capacity.
Wro-o-o-o-ng! The grates are plugging up with leaves very rapidly. In a recent heavy rain, both culverts were completely submerged by 4 inches, and the water level was lapping at the overflow spillway. To remove the leaves, we needed to wade into the water and pull away handfuls of leaves, with considerable force.
Most of the leaves seem to be surface litter. If we had a wide-open culvert, I am sure they would just flow through. But we are worried that kids or animals might get sucked into the culvert.
Has anyone else faced this problem? Any ideas for us?
Welcome to the forum I have a six acre pond that has two 24” culverts side by side and no cover over either one they haven’t stopped up in the 10 yrs that they have been there, have had a few branches that got in front of opening nothing to impede the flow. Only once in ten years has the water ever gotten to about 2” deep in culverts not enough to suck anything other than sticks and leaves
One of my small ponds has a grate over the drain culverts and it would completely cover with debris. I ended up putting a piece of fencing in front of it at a steep angle with the top just above the grate level this catches the debris before it gets to the drain and is able to gather more debris than the grate would clog up with. When the water level gets to the culvert it is flowing over the fence but all the debris is held in the fence.