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?
