[gulley]

We have had a lot of rain in California this season and the crawl space under my house has flooded twice and I've had to pump out hundreds of gallons of water. I need to improve the drainage along the side of my house where – along the lot line, about six feet from my house – my neighbor has a hedge that stands in a mound of soil slightly elevated above ground level and that runs the length of the lot, about 120 feet. (see drawing attached). Our lots slope very slightly toward the street.

What can I do to improve the drainage on the side of the house between me and my neighbor? (Our house has gutters and flex pipe that carry water away from the house, but I didn't show them in the drawing.)

 

[chandler48]

When was the neighbor's berm installed, and why? If it was recently and to prevent washing his property, then it probably wasn't permitted and should not be there.

 

[stick\shift]

Assuming the berm is staying, I would put in some kind of artificial creek to drain the water away instead of letting it soak into the ground. Like a pond liner with rock mulch on top of it.

 

[SW Dweller]

Best check with your county AHJ about water run off. A whole lot of people get involved when you start moving water off your property.

We should all have ways to contain the water where it falls. A whole lot less flooding that way.

 

[Nealtw]

The berm may stop surface water but the problem is ground water and the berm ah little to do with that.
A drain system with a permanent pump is what is needed.
The drain should be down at footing level.

 

[SPS-1]

Basically, you need to give the water someplace to go, keeping in mind that water flows downhill.

So you need to find a low area that you can direct rainwater to. (And directing it to the property of your neighbor on the other side, is not the best idea)
But maybe the street is lower and an option ?
You might have to make a map of your property with heights. A laser or even stakes, string, and line level can be used.

In many places, cities had bylaws prohibiting modifying the terrain in ways that effect how water flows over (at least) other's properties. Hence the above comments about your neighbor's berm.

 

[DoomsDave]

@gulley nice to meet you!

Where in CA are you? What kind of situation I.e.rural, suburban or urban?

In my opinion this is a complex thing and the more facts the better.

Hope you ain’t getting washed off by an atmospheric river.

 

[gulley]

California central coast. Suburban. Rainy season almost over. You know our seasons right? Drought, fire, earthquake and flood.

 

[FM3]

What can I do to improve the drainage on the side of the house between me and my neighbor?

Probably a swale or a french drain. Need real pictures of the yard.