Last night, we had a strong thunderstorm, and the culvert flowing through the Oxbow feeding the canal was washed out.
The ‘bridge’ over the culvert is the old towpath for the original canal. The water flows from Minerva Deland school playing fields into The Oxbow Lake.
This structure been recently refurbished using plastic pipes, as the old ones were rusted out.
Seeing as how this is a new repair, how did this happen after only ONE heavy storm?
It’s the overall design that is at fault. These small pipes simply dam up the exit with debris that naturally falls into flooding streams.
The water can’t escape, and so it flows over the top of the trail.
The next problem is that no rip-rap or concrete barrier was placed on the upstream side of the trail, so scouring of the gravel took place.
Small particle size gravel was used as fill over the pipes. This tactic was used before and rocks about 6″ – 8″ were used, and these washed out.
After every rain storm, The Town of Perinton staff visit and remove the debris. Unfortunately, they don’t take it away, and leave on the side of the culvert, where it washes back and clogs the pipes again.
Perhaps the answer is to remove these pipes and simply replace them with a wooden footbridge? There would be much less maintenance and it would prevent motorized vehicles from accessing the trail?
This is a classic case of a culvert becoming clogged with debris and subsequently over-topping. It just took one thunderstorm. Imagine if this had been on a canal embankment dam culvert or spillway. The dam overflows and the soil is easily washed out – scouring. A couple of hours of this and an embankment dam would fail.
Updating this post July 24th 2018
Last night’s heavy rainstorm caused more damage to our culvert. Much soil was eroded from one side where the culvert is lined with concrete. Scouring has occurred behind the wall, which will eventually collapse.
Another hole has appeared more centrally and a great deal of gravel has been washed away.
A lot of bedrock is now exposed at the upstream side of the culvert tubes, and of course, they are partially blocked by debris.
I would guess that another rainstorm will wash out the area completely. At least it will make pipe removal a simple process!
UPDATE 8 14 2018
A huge rainstorm washed out the rip-rap, pipes and gravel completely today.
UPDATE 8 15 2018
All traces of bridge – gone!
Here’s the old pipes.