Foundation

French Drains and Gutters: Fixing a Wet Side Yard in Houston

By Houston Gutter Repair Co. · September 20, 2026 · 5 min read

The side yard is the narrow strip between your house and the neighbor's fence — eight feet wide in most of Houston's newer subdivisions, five feet on the zero-lot-line homes in Cypress and the Energy Corridor. It's where the AC condensers live, where the mud never dries, and where two houses' worth of roof water ends up when both sets of downspouts point at it. Before you price a French drain, work out where the water is coming from.

Step one: count the downspouts

Stand in the wet strip and look up. Most side yards in Houston have a downspout from your house and one from the neighbor's, and often two from each. A 40-foot side wall on a two-story home carries roughly 800 square feet of roof, which in a two-inch-an-hour storm is about 1,000 gallons an hour arriving in a strip of clay the size of a parking space. Then it sits there, because Houston clay drains at something like a tenth of an inch an hour.

If the downspouts end at the wall or at a splash block, the fix is not a drain. It's moving the water. A rigid extension or a buried line running the downspout to the front or back yard, where the water can spread out, is $40–$500 per downspout and solves most wet side yards outright. Downspouts and your Houston slab has the full price table.

Step two: check the grade

The side yard should slope away from your foundation toward a swale — a shallow ditch — that runs to the street or the back of the lot. Builders cut that swale; ten years of mulch, sod and a neighbor's new patio fill it in. If the strip is dead flat, or the low point is against your slab, the water has nowhere to go even with the downspouts extended. Re-cutting the swale is a landscaping job, often $300–$800, and it's cheaper than any drain.

Step three: only now think about a drain

A French drain is a trench with a perforated pipe in gravel, wrapped in fabric, that collects water along its length and carries it somewhere lower. It works when there's a "somewhere lower." On a flat Houston lot that usually means a pop-up emitter at the curb, a connection to a storm inlet where the city allows it, or a sump. Without fall, a French drain is a buried bathtub.

What one costs here:

Those are typical ranges, not a quote, and drain work is a landscaper's or drainage contractor's job rather than ours. What we do is make sure you're not paying for one you don't need.

The order that saves money

1. Extend or bury every downspout that lands in the side yard. Yours and, if the neighbor's willing, theirs.
2. Re-cut the swale if it's gone.
3. Wait through two storms and look again.
4. If it's still wet, get a French drain quote — and make sure the quote shows where the water exits.

We've seen homeowners in Cinco Ranch and Riverstone spend $4,000 on a French drain that fed into the same clay it was draining, when the actual problem was four downspouts ending at a splash block. The drain didn't fail; it just had nothing to do with the water.

Why gutters are the first thing to check

A gutter that overflows on the side wall in every storm puts more water in the side yard than the downspouts do, and a French drain won't touch it. Sheeting over the edge means the run is undersized, pitched wrong or short a downspout — see why gutters overflow in Houston rain. Adding a downspout to that run and sending it to the back yard is a $200–$400 gutter repair and it's the thing that fixes most side yards.

The other gutter fault that fills a side yard is a missing gutter. Plenty of 1990s homes in Katy and Pearland have gutters on the front and back only, so both side walls shed straight down into the strip. A seamless gutter on the side walls with the downspouts run to the front is often the whole fix.

Mosquitoes and the wet side yard

A side yard that stays wet for a week after a storm is breeding mosquitoes, and Harris County Public Health will tell you standing water is the number one thing homeowners can control. Moving the downspouts dries it out in a day. That alone is worth the $200.

What we'll tell you on an estimate

If you call us about a wet side yard, we'll look at the gutters and downspouts above it and give you a price for whatever they need. If the water is still going to pool after that, we'll say so and suggest a drainage contractor — but in our experience the gutter side fixes it more often than not, and it's the cheaper half to try first.