How close to my concrete driveway can I install a French drain?

Question

Hi Team

I have a sloping driveway. The slope falls away from thr garage and shed to the street.

I have water run off straight down the driveway through what appears to be a partially deliberate depression in the driveway concrete but water runs off far more than this small channel. I want to divert water to help prevent undercutting the driveway and to improve draining.

I thought a French drain is my best option. I am running French drain elsewhere on the property so this would be an easy continuation.

How close to the concrete can i safely install a French drain to the edge of the concrete?

MitchellMc · Answer

This guide on How to fix a muddy lawn shows channel drain installation @KBdoesDIY. Also, this guide on How to install garden drainage showcases a french drain.

Mitchell

KBdoesDIY · Answer

Thanks, as always!

Capturing and redirecting the water to some new garden beds was my thoughts but a drain might be good in combination.

Do you have any posts about how to install channel drains? Won't connect to storm water, rather I'll try to use the water where it's needed.

MitchellMc · Answer

Hi @KBdoesDIY,

I'd be cautious about excavating immediately alongside the driveway, as you don't want to remove or disturb the material supporting the edge of the concrete. As a general approach, I'd keep the French drain at least 300mm away from the driveway edge. If you need to excavate deeper than this, I'd increase that distance so you're not digging into the driveway's supporting base.

I'd also question whether a French drain is the best solution for the surface water you're describing. French drains are particularly useful for collecting groundwater and water moving through saturated soil. For runoff flowing down the surface of a concrete driveway, a grated channel drain installed across or alongside the driveway and connected to an appropriate stormwater discharge point can be more effective. As a grated drain might only require a channel around 120mm deep, it could potentially be installed immediately alongside the driveway without significantly disturbing the material supporting it.

Please be aware that connecting drainage to a stormwater system is considered plumbing work and must be completed by a licensed plumber.

If the water is also saturating the ground beside the driveway and you're trying to prevent that moisture from contributing to erosion beneath it, then your proposed French drain could certainly be useful.

Here's a helpful step-by-step guide: How to fix a muddy lawn.

Let me tag @KPD, @Tomahawk1, @ycdieu, @sandysmiles1969 and @Venugopal, who have all dealt with their own drainage issues in the past, to see if they have any thoughts.

Please let me know if you have any questions.

Mitchell