Yard Drainage Options Around a Houston Foundation
Yard water near a Houston slab can be moved with a swale, a dry well or regrading; each works differently, and the dry-well guidance cited here is from Washington State, not Texas (Texas NEMO (Texas A&M University System with Texas Sea Grant and AgriLife Extension), Grassed Swale fact sheet, checked 2026-10-23; WSU Extension, Clark County, Improving Drainage, university extension page, checked 2026-10-19). SteadyHomeHouston publishes free guides on Houston foundation repair. When quote requests open, the contractor we refer you to will pay us for each referral; you pay us nothing. We're not a contractor.
Updated
Quote requests are coming soon. For now, call (832) 646-1494 or email hello@steadyhomehouston.com.
📞 Call (832) 646-1494When quote requests open, the contractor we refer you to will pay us for each referral; you pay us nothing. We're not a contractor.
Call (832) 646-1494 or email hello@steadyhomehouston.com.
Why water near a slab matters
Our sinking foundation guide covers the soil side; this page sticks to where yard water goes.
Swale
A Texas A&M program fact sheet says a grassed swale "can be thought of as a broad, shallow vegetated drainage ditch" that slows stormwater as it drains. It recommends land with a 1 to 2 percent slope, says the soil "should also be permeable to allow for infiltration," and adds: "Any water pooled after a storm event should be completely gone within 48 hours" (Texas NEMO (Texas A&M University System with Texas Sea Grant and AgriLife Extension), Grassed Swale fact sheet, checked 2026-10-23).
Dry well
A Washington State University extension guide written for Clark County, Washington, calls a dry well "a small pit lined with geotextile fabric or weed cloth and filled with 1½” to 3” gravel," and says the surrounding soil "should be sufficiently permeable to allow adequate infiltration of the runoff" (WSU Extension, Clark County, Improving Drainage, university extension page, checked 2026-10-19). That is Washington guidance, not a Texas or Houston rule, and it was not written for Houston clay. Not engineering advice; ask a licensed professional engineer (TBPELS roster, checked 2026-10-19).
Grading the yard away from the house
In its owner's guide, the Foundation Performance Association, a Houston-based nonprofit professional organization, gives a target for the ground beside the slab: "The grade falls 6” within 10’ (a 5% slope)." The same checklist asks whether downspouts "connect to pipes or swales" and whether roof water drains 5 feet away (FPA-SC-20-0, Owner's Guide to a Better Foundation, 2016, checked 2026-10-17). Fill or regrading near a slab can also be a permit matter: in unincorporated Harris County, the engineering FAQ says bringing in dirt outside a Special Flood Hazard Area takes a residential application, a site plan and a fill affidavit showing how water will move afterward (Harris County Engineering permit FAQ, official county page, checked 2026-10-19).
Comparison table
| Option | What it does | Placement note | Source |
|---|---|---|---|
| Swale | Grassy, shallow channel that carries surface runoff away | Pooled water gone within 48 hours | Texas NEMO (Texas A&M University System with Texas Sea Grant and AgriLife Extension), Grassed Swale fact sheet, checked 2026-10-23 |
| Dry well | Gravel-filled pit that lets clean runoff soak into soil | Washington guidance: surrounding soil must be permeable; ask a professional engineer | WSU Extension, Clark County, Improving Drainage, university extension page, checked 2026-10-19 |
| Grading | Ground sloped down and away from the slab | Falls 6 inches within 10 feet (5%) | FPA-SC-20-0, Owner's Guide to a Better Foundation, 2016, checked 2026-10-17 |
| French drain | Buried rock-and-pipe trench (Washington guidance) | Details live on the French drain page | WSU Extension, Clark County, Improving Drainage, university extension page, checked 2026-10-19 |
Who to ask
Inside a city, ask whether the work needs a city permit, and who pulls it; in unincorporated areas, ask whether the work needs a permit or other approval, and who gets it. If the slab is already showing distress, have a professional engineer look at grading and drainage as part of a foundation inspection before anyone moves soil. Watering the soil in dry spells is a separate topic, covered on our foundation watering page.
Compare foundation repair options
Drainage work is often priced separately from slab repair; credited Houston-area repair ranges are on our cost page. Quote requests are coming soon. For now, call (832) 646-1494 or email hello@steadyhomehouston.com.
When quote requests open, the contractor we refer you to will pay us for each referral; you pay us nothing. We're not a contractor.
Related: French drains · Foundation watering · Signs of foundation problems · Foundation repair guides · Home
Sources
- Texas NEMO (Texas A&M University System with Texas Sea Grant and AgriLife Extension), Grassed Swale fact sheet, checked 2026-10-23
- WSU Extension, Clark County, Improving Drainage, checked 2026-10-19
- FPA-SC-20-0, Owner's Guide to a Better Foundation, 2016, checked 2026-10-17
- Harris County Engineering permit FAQ, checked 2026-10-19
FAQ
What is a swale?
Texas NEMO, a Texas A&M education program, describes it as a broad, shallow ditch planted with grass that slows runoff and lets it soak in where the soil allows (Texas NEMO (Texas A&M University System with Texas Sea Grant and AgriLife Extension), Grassed Swale fact sheet, checked 2026-10-23).
Does a dry well work in Houston clay?
We can't say. Washington State University's Clark County, Washington extension guide says the soil around a dry well "should be sufficiently permeable to allow adequate infiltration of the runoff" (WSU Extension, Clark County, Improving Drainage, university extension page, checked 2026-10-19); it is not Houston guidance. Not engineering advice; ask a licensed professional engineer (TBPELS roster, checked 2026-10-19).
How much should my yard slope away from the slab?
The Foundation Performance Association's owner's guide uses a fall of 6 inches within 10 feet, a 5% slope (FPA-SC-20-0, Owner's Guide to a Better Foundation, 2016, checked 2026-10-17).
Is a French drain the same thing as a swale?
They solve different problems. One moves surface water across the lawn in the open; the other collects water below ground in rock and pipe, which our French drain page explains in depth (Washington guidance: WSU Extension, Clark County, Improving Drainage, university extension page, checked 2026-10-19).
Sources
- Texas NEMO (Texas A&M University System with Texas Sea Grant and AgriLife Extension), Grassed Swale fact sheet (nemo.tamu.edu, checked 2026-10-23)
- WSU Extension, Clark County, Improving Drainage (extension.wsu.edu, checked 2026-10-19)
- TBPELS roster (pels.texas.gov, checked 2026-10-19)
- FPA-SC-20-0, Owner's Guide to a Better Foundation, 2016 (foundationperformance.org, checked 2026-10-17)
- Harris County Engineering permit FAQ (oce.harriscountytx.gov, checked 2026-10-19)