Short answer
The goal is even soil moisture all the way around the house, not wet soil. Use a soaker hose or drip line in the band of soil next to the slab (Plano defines its foundation zone as the first 24 inches), water slowly outside the 10 a.m. to 6 p.m. window, and stop before water runs off. Plano and Frisco currently allow foundation watering by hand or soaker hose for up to 2 hours on any day, and Prosper allows it year-round in all zones. Rules change with drought stages, so check your city's page before you set a timer.
Why watering the soil next to a slab helps
Collin County's most common soil, Houston Black clay, has a plasticity index of about 44 to 55 and a "very high" shrink-swell rating in the USDA's NRCS soil survey data. Dr. Jake Mowrer of Texas A&M AgriLife Extension described these clays in a 2022 interview: "When they get wet, they swell, and when they get dry, they shrink." AgriLife's Travis County office adds that such clay soils "absorb water very slowly", and the North Texas Municipal Water District puts local clay's intake at "about a tenth of an inch per hour".
A slab resting on that soil rises and falls with it. The problem is uneven movement. The Foundation Performance Association, a Houston group of engineers and industry members, says in its maintenance guide that "uniformity is the key: uniform moisture content in the soil, uniformly maintained in all areas around the foundation." The Texas Section of the American Society of Civil Engineers makes the same point in its residential foundation guidelines, saying near uniform moisture on all sides "may be beneficial" and that "caution should be advised against excessive watering."
Why it matters right now
The US Drought Monitor showed no drought in Collin County on August 11, 2026. By September 22, 79% of the county was in extreme drought or worse, according to the Drought Monitor's county statistics. The National Weather Service in Fort Worth noted that as of September 5, DFW had gone 52 days in a row without measurable rain. That is the kind of stretch when clay shrinks and gaps open at the edge of a slab.
How to do it
Where the hose goes
Plano is the only Collin County city found that defines the zone in writing. Its Water Management Plan defines "foundation" as "the first 24 inches of soil from foundation slab" and says soaker hoses should be used "only within a tree's dripline or within 24 inches of a foundation." The FPA maintenance guide says irrigation "should be done at least one to two feet away from the foundation, and then lightly."
In practice that means:
- Lay a soaker hose or drip line in the soil band beside the slab, not against the concrete and not out in the lawn.
- Go all the way around the house, including the shady side and behind shrubs. Watering one side only is what uneven moisture looks like.
- Cover it with mulch so it doesn't get sun damage and less water evaporates. The FPA suggests uniform ground cover extending at least five feet from the foundation.
How much and when
- Slowly. Clay takes water in slowly, so a slow soaker or drip line works better than a spray head, which mostly runs off.
- Outside the 10 a.m. to 6 p.m. window in the warm months, when most local rules restrict outdoor watering.
- Stop before runoff. Every city rule below says no runoff, and water pooling against the slab is a problem of its own.
- Adjust by feel. The soil next to the slab should be damp, not muddy. If it's still wet a day later, you're watering too much.
There is no single schedule that suits every house, soil and sun exposure, and we haven't found an official source that sets one. Treat any fixed "minutes per day" figure as a starting point, then watch the soil.
Common mistakes
- Sprinklers spraying the wall or slab. The FPA says not to let sprinklers spray the structure.
- Soaking only in a crisis. Big swings from bone dry to saturated are what move slabs. Steady beats heroic.
- Ignoring leaks. A dripping outdoor tap or AC condensate line wets one spot. The FPA lists leaking plumbing, drains and condensate lines among the causes of "local high moisture contents that can result in differential movement."
- Trees next to the house. Tree roots pull a lot of water from clay. The FPA suggests watering trees well away from the foundation so their roots grow in that direction.
What the cities currently allow
Plano, McKinney, Allen and Frisco are member cities of the North Texas Municipal Water District. Its 2024 Water Conservation Plan sets a year-round baseline: from April 1 to October 31, spray irrigation is limited to no more than two days a week, with no lawn irrigation from 10 a.m. to 6 p.m.; from November 1 to March 31, at most one day a week. The plan adds that "additional irrigation may be provided by hand-held hose with shutoff nozzle, use of dedicated irrigation drip zones, and/or soaker hose provided no runoff occurs." Drought stages can tighten these rules, and each city publishes its own version.
These rules change with drought stages, sometimes quickly. Everything below was checked on September 30, 2026. Check your city's page before relying on it.
- Plano: From April 1 to October 31, sprinklers run on two set days by address, with none from 10 a.m. to 6 p.m. Plano's April 2026 announcement says foundations and landscaping "may be watered for up to 2 hours any day by a hand-held hose or soaker hose," and low-flow drip systems "may operate as needed." See also Plano's watering guidelines and our Plano page.
- Frisco: Frisco's Water Efficiency Plan allows a "hand-held hose with shut off nozzle, soaker hoses, drip irrigation, or bubbler systems when needed, no more than 2hrs per day," and says "water runoff should not occur." Sprinkler days are on the city's watering schedule. See our Frisco page.
- Prosper: Prosper's watering guidelines assign sprinkler days by zone and list foundation and tree watering as permitted in all zones, by shut-off nozzle, drip lines or soaker hoses, year-round. See our Prosper page.
- McKinney: McKinney's watering FAQ describes a summer conservation plan: water on your trash day "and three days later if necessary," with no outdoor watering from 10 a.m. to 6 p.m. Trees, flowers and gardens can be watered more often with "watering cans, hand-held hoses, soaker hoses, or dedicated zones using drip irrigation." Foundations aren't named, so ask the city before assuming the same exception applies. See our McKinney page.
- Allen: the city's watering page allows a hand-held hose, soaker hose or dedicated drip zone at any time, provided no runoff occurs. Sprinklers are limited to two days a week and banned from 10 a.m. to 6 p.m. from April through October. See our Allen page.
Watering is maintenance, not a repair
Consistent watering can help limit seasonal movement, but it doesn't undo movement that has already happened, and it isn't a substitute for an engineer's opinion if you're seeing growing cracks or sticking doors. See signs of foundation problems for what to watch, and drainage correction for the gutter and grading side of moisture control.
If an independent engineer has recommended repair or drainage work, this guide can pass your request to a local foundation repair company. See how it works.
Frequently asked questions
How far from the foundation should a soaker hose be?
Plano's Water Management Plan defines the foundation zone as the first 24 inches of soil from the slab and limits soaker hoses to within 24 inches of a foundation or a tree's dripline. The Foundation Performance Association suggests watering at least one to two feet from the foundation, lightly. Keep the hose in that band, not against the concrete.
Can I water my foundation during watering restrictions in Plano or Frisco?
As of September 30, 2026, yes. Plano allows foundations to be watered for up to 2 hours on any day by hand-held hose or soaker hose, and Frisco allows hand, soaker, drip or bubbler watering up to 2 hours a day with no runoff. Rules change with drought stages, so check the city's page first.
Should I water into the gap between the soil and the slab?
No. The Foundation Performance Association says not to water directly into the gap, because water can run under the slab and wet one area much more than the rest. Water the soil beside it slowly instead.
How long should I run a soaker hose on my foundation?
No official source sets one schedule for every house. Water slowly, outside 10 a.m. to 6 p.m. in summer, and stop before runoff. Aim for soil that stays damp, not muddy, and adjust from there. City rules cap foundation watering at 2 hours a day in Plano and Frisco.
Will watering my foundation fix cracks I already have?
No. Even moisture can help limit future seasonal movement, but it doesn't reverse past movement. If cracks are growing or doors are sticking, have an independent Texas-licensed professional engineer look at the house.