Retaining Wall Drainage in Frisco, TX

Why Retaining Wall Drainage Matters in Frisco

A retaining wall holds back soil, and the water in that soil pushes too. Without drainage, hydrostatic pressure builds behind a wall and can make it bow, crack or collapse.

The largest soil mapped in Collin County, a clay, takes in water rapidly when it is dry and cracked, and very slowly when it is moist. In dry periods its cracks run 1/2 to 4 inches wide at a foot deep.

May and October are the wettest months at DFW Airport, at 4.78 and 4.37 inches. July and August are the driest, at 2.08 and 2.18 inches. A 10-year storm at Frisco is estimated at 2.49 inches in one hour, and a 100-year storm at 3.57 inches. Over 24 hours, the estimates are 5.98 inches for a 10-year storm and 9.32 inches for a 100-year storm.

If your wall stays wet, seeps through the face or has started to lean, call or send the form. A free on-site estimate checks the drainage first.

What Goes Into Retaining Wall Drainage in Frisco

The diagram below shows a drained block wall. Here is what a drained wall can include, plus one upkeep habit.

Perforated pipe at the base. Basic drainage starts with a perforated pipe at the base of the wall.

Gravel backfill. The zone behind the wall is backfilled with gravel.

Free-draining gravel. A segmental block maker recommends free-draining gravel with virtually no fines, which it calls “wall rock”.

Filter fabric. The same maker recommends filter fabric above the wall rock and below the topsoil.

Weep holes. Weep holes complete basic drainage. Pipes, gravel, weep holes and criblock designs are all ways to drain a wall.

Downspouts. This one is a habit, not a part: send downspouts away from the wall.

Call or send the form, and we will check which of these your wall has.

Adding Drainage Behind an Existing Retaining Wall in Frisco

If a wall was built without drainage, adding it is its own job. Fixing a wall that does not drain runs $60 to $70 per linear foot, done by excavating behind the wall.

If the wall is already failing, the job may become a repair, at $250 to $1,250 per job, or a full remove and rebuild, at $6,000 to $14,500. The retaining wall repair page covers both.

You will know which one you are looking at after the free on-site estimate. Call or send the form.

Frisco Rules on Retaining Walls and Drainage

Frisco’s code has several drainage rules that touch walls and fences. No part of a retaining wall may interfere with or alter a drainage swale between lots. A fence shall not adversely affect drainage, and fences are not permitted in FEMA-designated floodway areas.

The city also requires that no portion of any residential lot be in the 100-year floodplain, and altering or filling floodplain needs a flood study. Frisco keeps watershed studies for Cottonwood Branch, Panther Creek, West Rowlett Creek, Rowlett Creek, White Rock Creek and Stewart Creek, and the Cottonwood Creek Greenbelt runs 77 acres.

For the wall itself, no permit is required for a masonry retaining wall less than 24 inches tall, and a retaining wall taller than 36 inches must follow a design submitted by a registered engineer. The permit fee is $150 per wall, and it doubles if work starts before the permit is obtained. Check with Development Services, Building Inspections before you build. Contractors need a valid Frisco contractor registration and a permit to work in the city.

Keeping Retaining Wall Drainage in Frisco Working

Habits that help a sound wall include:

clean the weep holes yearly;
keep downspouts pointed away from the wall.

Between those, watch for signs of trouble such as leaning or bowing, leaking or seeping, cracking, efflorescence and foundation shifting. If one shows up, call us. We answer Mon–Sat 8–6.

What the Free On-Site Estimate Checks

On a drainage visit, we look at:

whether the wall has a pipe, gravel or weep holes, and whether water is getting out;
where roof and yard water reach the wall;
swales between lots and any creek or greenbelt nearby;
the height and condition of the wall;
room to excavate behind it, since tight or difficult sites need more manual labor;
the soil, since clay-heavy soil can raise excavation labor by up to 50%.

Your price is set at the free on-site estimate. Call or send the form to set it up.

Cross-section diagram of a segmental block retaining wall with interlocking blocks, free-draining gravel behind them, filter fabric under the topsoil and a perforated drain pipe at the base — How a drained block retaining wall is built: free-draining gravel and a perforated pipe at the base carry water away, so pressure does not build up behind the wall.

Retaining Wall Drainage Cost in Frisco

Typical ranges.
Job	Typical price
Block (segmental) wall	$15–$50 per sq ft of wall face
Natural stone or boulder wall	$20–$100 per sq ft of wall face
Timber wall	$13–$30 per sq ft of wall face
Poured concrete wall	$20–$40 per sq ft of wall face
Retaining wall repair	$250–$1,250 per job
Drainage added behind an existing wall	$60–$70 per linear ft
Engineering design	$500–$750 per wall

Typical ranges.

Job

Typical price

Block (segmental) wall

$15–$50 per sq ft of wall face

Natural stone or boulder wall

$20–$100 per sq ft of wall face

Timber wall

$13–$30 per sq ft of wall face

Poured concrete wall

$20–$40 per sq ft of wall face

Retaining wall repair

$250–$1,250 per job

Drainage added behind an existing wall

$60–$70 per linear ft

Engineering design

$500–$750 per wall

What Happens After You Call

Call or send the form. Tell us about the slope, the wall you have or want, and how to reach the spot.

Free on-site estimate. We measure the height and length, check the drainage and the soil, and look at access for equipment.

Your price. Your price is set at the free on-site estimate.

Build. The wall is built to the plan from the estimate.

Local Retaining Walls Conditions in Frisco

Houston Black clay is the largest mapped soil in Collin County, about 37% of its mapped acres, and it has high shrink-swell potential with cracks 1/2 to 4 inches wide in dry periods.

Water enters this clay rapidly when it is dry and cracked and very slowly when it is moist. Walls on clay often need extra reinforcement, and clay-heavy soil can raise excavation labor by up to 50%.

In Denton County, the largest mapped soil components are Sanger, Somervell, Callisburg, Gasil and Ponder, not Houston Black.

DFW Airport averages 37.01 inches of rain a year, with May and October the wettest months.

We work in Phillips Creek Ranch, Frisco Lakes, Richwoods, Newman Village, Starwood, Grayhawk, Hollyhock, Lone Star Ranch, Plantation Resort and Lexington, near The Star, Toyota Stadium, Riders Field, Stonebriar Centre, Frisco Square, National Videogame Museum and PGA of America headquarters.

Permits: City of Frisco Development Services, Building Inspections: Frisco requires no permit for a masonry retaining wall under 24 inches tall, and a retaining wall taller than 36 inches must follow a design submitted by a registered engineer. The permit fee is $150 per wall. Contractors must hold a valid Frisco contractor registration.

Retaining Wall Drainage Questions in Frisco

Do I need a permit for a retaining wall in Frisco?

Each city sets its own wall height at which a retaining wall needs a permit, and some require one at any height. Check with the Frisco permit office before building. The free on-site estimate includes measuring the wall height that rule is based on.

When does a retaining wall need an engineer?

Where a city requires an engineered design, it sets its own wall height for it, and some cities publish none. Check with the Frisco permit office. The free on-site estimate measures the wall height. Your price is set at the free on-site estimate.

What does a retaining wall cost in Frisco?

Depending on the project, block walls run $15 to $50 per sq ft installed, natural stone $20 to $100, poured concrete $20 to $40 and timber $13 to $30. Height, access, slope, soil, drainage and permits move the price, so the final number comes from the free on-site estimate.

How long does a retaining wall last?

Concrete walls last 50 to 100 years, stone 40 to 200 years and wood 10 to 40 years. Without drainage, water pressure behind a wall can make it bow, crack or collapse.

Why is my retaining wall leaning?

Water pressure from poor drainage, and footings without enough strength or missing rebar, can cause a wall to lean. The free on-site estimate looks at the wall to find the cause.

Does a retaining wall need drainage?

Yes. Basic drainage is perforated pipe at the base of the wall, gravel backfill and weep holes. Clean the weep holes yearly and send downspouts away from the wall.