Rainwater management and drainage

[Chapap]

I’ve run into several drainage problems over the years, most of which weren’t really solved cause you just can’t make water do something it doesn’t want. My current dilemma is a flooding back porch. It’s cut into a hill. Ground level is about +2’ at the far end of the porch and water drains to that side, away from the house. After a good rain, it’ll fill up and stay full for a couple days. The water table is far below (I’ve dug 5’ and was bone dry) and soil is sandy and just a tad bit dusty.

An actual drain pipe is pretty much out of the question. Would a wellpoint be a good option? I could knock a brick out of the retaining wall and drive a wellpoint there to get some surface area down in the ground for the water to soak in quicker. Would that make a noticeable difference?

 

[bobbywalter]

French it

 

[Chapap]

French it

Kinda my thought. But driving one wellpoint requires much less digging and is…. kinda the same?

 

[bobbywalter]

Start easy . ...

 

[Eddo Rogue]

+1 French drain.

 

[Ranger850]

I'm not familiar with a 'wellpoint' but French Drains can be cheap and easy. If done right, they will last forever. Good flow in the pipe is key. You don't want water sitting in them and draining out of the bottom holes. You want it moving all the way through. I was going to french drain my new front lawn, but the line I need to take has too many roots from the Oak tree so we are still trying to figure out how to keep the water away from the front porch.

 

[Chapap]

I'm not familiar with a 'wellpoint' but French Drains can be cheap and easy. If done right, they will last forever. Good flow in the pipe is key. You don't want water sitting in them and draining out of the bottom holes. You want it moving all the way through. I was going to french drain my new front lawn, but the line I need to take has too many roots from the Oak tree so we are still trying to figure out how to keep the water away from the front porch.

A wellpoint is typically (100% according to what I read) used for construction dewatering and small hand pump wells. They are a perforated, stainless pipe that start at 1.5” x 36” with a thick, pointed steel cap at the end. You drive them down into the water table to get water, but as I said, I want water to go the other way through it.

 

[Eddo Rogue]

I have a little French drain for just the laundry machine in the guest house. the dirt is mostly decomposed granite, so it didn't take much Frenching. Works good.

 

[Rimjam]

French drain is my vote. More effort initially but virtually maint free after that & no moving parts to wear out.

 

[RonD]

Water runs downhill

If there is flooding then the downhill part has equalized, water level is the same so can't drain/no downhill anymore
OR
A new easier downhill was found, over the wall, lol

If the water is coming over the top of retaining wall in heavy rains then put the french drain at the top of the wall, easier to do, so it can drain off the excess water in those heavy rain periods

 

[Chapap]

So here’s what I’m working with. This is a project of “I bet I can do it” as opposed to a real problem that needs to be fixed. Red box is retaining wall (about 2.5’ on left and 1’ on right). Red line on right is house. Green is groundline. Blue is drain location.

White is concrete slab. It slopes away from house, and portion on right is flat sidewalk that runs away/around the house. Ground continues to slope beyond that. I’m trying to keep the low spot from filling.

I installed the wellpoint and added a silt catch thingy with cleanout access cause I figure why not. I lined it with some coarse screening to hold pea gravel and drilled holes in the bottom so it doesn’t just hold water. We shall see what happens.