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

By Houston Gutter Repair Co. · September 20, 2026 · 7 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.

In the French drain vs gutters debate, the gutters usually win on cost: most wet side yards are a downspout problem first and a drainage problem second. Here's how to tell which one you have.

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 a gutter contractor's. The point of this guide is to 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.

It's easy to spend $4,000 on a French drain that feeds into the same clay it's draining, when the actual problem is 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 standing water is one of the few mosquito sources a homeowner can control directly. Moving the downspouts dries it out in a day. That alone is worth the $200.

After the fix

Once the downspouts are moved or the drain is in, check the side yard after the next two storms. It should be firm underfoot within a day. If it isn't, note where the water still sits and how long it takes to go.

Watch it rain before you spend

The cheapest diagnosis is a rainy afternoon. Put on boots, stand in the side yard during a storm, and watch. Where does the water come from: the gutter edge, the downspout, the neighbor's roof, or the ground itself? Where does it go next? Take a short video. Ten minutes in the rain will tell you more than any estimate, and the video makes it easy to show a contractor exactly what happens.

Don't forget the neighbor's water

In a narrow side yard, half the water may come from the house next door. If their downspouts point at the shared strip, extending yours won't dry it out. It's worth a friendly conversation: show them where the water pools, and suggest both of you turn your downspouts toward your own front or back yards. Many neighbors are happy to, especially if the wet strip is also hurting their side. If a fence or a shared drain is involved, check your HOA rules or the city's guidance before changing anything that affects the property line. Simple fixes, like turning a downspout or adding an extension, rarely need more than agreement between the two of you.

A side-by-side look

Questions to ask a drainage contractor

• Where exactly does the water exit, and is that point lower than the trench?
• What pipe and fabric are you using, and how deep?
• How will the AC pad, fence posts and utility lines be handled?
• Can the downspouts be tied in, or kept separate?
• What happens if the outlet clogs, and how is it cleaned out?

Mistakes with wet side yards

• Laying gravel on top of clay and calling it drainage. The water sits under the gravel instead.
• Tying downspouts into a French drain that's already struggling, which floods it.
• Building up beds against the foundation so the soil slopes toward the house.
• Paving the strip without a channel drain, which turns it into a gutter of its own.

What a good estimate should tell you

If you call a gutter contractor about a wet side yard, a good one will look at the gutters and downspouts above it and price whatever they need. If the water is still going to pool after that, they should say so and point you to a drainage contractor — but the gutter side fixes it more often than not, and it's the cheaper half to try first.