Storm drain in backyard question
I’ve got a very tiny backyard (roughly 18′ by 17′) that was previously covered with large flagstones and cement… and which would flood almost uncontrollably when the main storm drain would get backed up. I’m currently having workers grade the yard away from the building (previously it angled TOWARD it!). They’re also planning to dry-lay the new pavers, which should allow for much better drainage.
But here’s the potential problem: they replaced the main storm drain pipe that was in the middle of the year, and which connects to the other storm drain lines in the cellar, as the existing one had failed and rotted away. A plumber had previously suggested adding a dry well/French drain beneath that pipe, so the pipe would really just be a backup to deal with heavy rains that overwhelmed the dry well, so I asked the workers to do that. However, there was apparently a bit of a misunderstanding, and instead they built what’s essentially a catch basin made of brick with a concrete bottom.
There have already been issues with mosquitoes in the tiny yard, so I’m worried that any standing water will make that worse– though the water in the basin did dry up in roughly a day and a half (though we’re mid-construction so the drain cover isn’t on yet). So here’s my question: Is this catch basin going to cause issues with standing water? Is there any easy way to make it permeable, either by drilling weep holes or by removing the cement at the botton and digging deeper and adding gravel (essentially making it a catch-basin/dry-well)? It’s not quite an ideal situation, and the main worker wants me to just trust him… but it’s a very small yard enclosed by another building!
Guest User | 1 year and 10 months ago
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justinromeu26 | 1 year and 10 months ago
i perhaps should not be commenting on this because i really have not done any reading on it but have done something like this in my own backyard to deal with standing water and made some assumptions about how they work:
i dug a column vertically down 8′ and ran a trench about 12′ across to that column. I put specially made pvc pipe in these and those pipes are wrapped in a cloth to keep dirt out of them. i back filled this with gravel and covered most of it with bricks (that i hoped would always let water through between them). Our issue here is clay and i try to get beneath the clay (i did not and i have no idea how deep the clay goes).
Have you looked at your soil or looked at what is under the top soil there? something tells me brooklyn is not made up of clay like it is around Juniper Swamp (where the park is now) over here. Before you do this, you want to know how well the soil drains (mine does not) and that might tell you how deep you have to go. But there is also this: i suspect the weight of the water above inside this system weighs so much that it pushes the water below further into the soil, dispersing it in all directions. That is what i HOPE with the clay i have in the back here. so i think you are right, go deep with it, 6′ below the walls of the device they made and fill it up with rocks to keep the surrounding soil from collapsing. the weight of the water will press the water further down (i think).
Here are some issues i had here: the lines between the bricks were not sufficient to drain the water (it worked for a while) because they clogged with detritus. so i drilled hole in the bricks. it rained last night and yes, i just checked and the water drained off. so they are still working but i am worried they will plug.
this kind of work is better left to pros who can TELL you what must be done. Even after i did what i describe above, i would tell someone “i am not qualified” if they called me and asked me to supervise this sort of operation.