Culvert fail

[drssg]

I've had good luck with french drains that do NOT have soil on top. Dig the trench, add a 4" perforated pipe, then fill the trench with 1" washed stone.

I have found that this will move plenty of water, and it does a better job at collecting surface water, so you don't have the squishy soil when mowing.

 

[Thomas]

Since NH known for growing rocks frost might have started push some rocks up.

 

[PILOON]

I've had good luck with french drains that do NOT have soil on top. Dig the trench, add a 4" perforated pipe, then fill the trench with 1" washed stone.****

I have found that this will move plenty of water, and it does a better job at collecting surface water, so you don't have the squishy soil when mowing.

****AND geotextile to filter out any fine silty material. would help a lot.

 

[drssg]

****AND geotextile to filter out any fine silty material. would help a lot.

Where would you put the geotextile material? I have heard of using that on top of the stone, if you are covering the drain with soil.

I do purchase the drainage line that is covered with a "sock" material. So far, my drainage lines have been working pretty well for the last twenty years.

 

[Pixguy]

I've had good luck with french drains that do NOT have soil on top. Dig the trench, add a 4" perforated pipe, then fill the trench with 1" washed stone.

I have found that this will move plenty of water, and it does a better job at collecting surface water, so you don't have the squishy soil when mowing.

There's no way a 4" perked pipe would take the gpm i get at times but I get your point.
I did wonder if water was getting under the culvert at some point and washing out the sand I had under it as there's lots of sand at the end pool.
Im agreeing that I need to dig out deeper, compact stone under it and just not sure I need stone on top other than to weight it down.

 

[ponytug]

I don't know if it helps, but the way I look at it, I think of culverts "floating" in soil, because they aren't as dense as soil since they are mostly filled with air. I think of having material on top of the culvert as weighing it down to keep it from floating up.

Compaction both increases the density and locks the material together to keep it from shifting and allowing the culvert to move. It also makes washouts less of an issue because there is less of a path for ground water.

If you have had material wash out, you might want to consider putting in an inlet of concrete or plastic to capture water and funnel it into the culvert.

All the best, Peter

 

[Pixguy]

I don't know if it helps, but the way I look at it, I think of culverts "floating" in soil, because they aren't as dense as soil since they are mostly filled with air. I think of having material on top of the culvert as weighing it down to keep it from floating up.

Compaction both increases the density and locks the material together to keep it from shifting and allowing the culvert to move. It also makes washouts less of an issue because there is less of a path for ground water.

If you have had material wash out, you might want to consider putting in an inlet of concrete or plastic to capture water and funnel it into the culvert.

All the best, Peter

Yes, I thought the same about the inlet and added a bag of concrete I had left over at the mouth (mostly covered by leaves now) but still continued to get sand at the end. Thank you for everyones comments so far.