A French drain is a trench with a perforated pipe bedded in washed gravel, usually wrapped in filter fabric, that collects water underground and carries it downhill to somewhere it can leave the property. Around Wichita, people usually ask for one because a yard stays soggy for days after a storm, water creeps into a basement, or a neighbor's runoff crosses the lot. Sometimes it's exactly the right fix. Sometimes reshaping the surface does the job for less money.
French drain or regrading?
| What you're seeing | Usually points to |
|---|---|
| Water runs toward the house across the surface after a rain | Regrading and swales. Surface water is easiest to move on the surface. See grading and drainage. |
| A low spot that stays wet even though the grade looks right | A French drain, or a surface drain inlet piped to an outlet |
| Water seeping through basement walls or up at the floor joint | A foundation (footing) drain at the base of the wall, often tied to a sump. This is a bigger dig, closer to foundation excavation around Wichita work |
| Downspouts dumping at the foundation | Extensions or buried solid pipe first; a French drain is not a downspout line |
| Groundwater seeping out of a slope or a hillside cut | An interceptor drain across the slope, above the problem |
A common mistake is tying downspouts into a perforated French drain. Roof water arrives faster than the gravel can take it and pushes back out of the pipe right where you didn't want it. Most contractors run downspouts in a separate solid pipe.
Drain tile vs. French drain
"Drain tile" is the old name, from the days of short clay tiles laid end to end, and around Wichita it usually means a foundation drain: perforated pipe in stone at the base of a basement wall. A French drain is the same idea used out in the yard. The parts look alike; what differs is where the pipe sits and what it protects.
| Exterior footing drain tile | Interior drain tile | Yard French drain | |
|---|---|---|---|
| Where it sits | Outside the basement wall, at or below the top of the footing | Inside the basement, below the floor slab along the walls | Anywhere in the yard, usually 18 to 24 inches deep |
| What it protects | The basement, from water building up against the wall | The basement, from water at the floor joint and under the slab | The lawn and the ground near the house |
| Where it goes | To daylight or a sump | Almost always to a sump pit and pump | To daylight, a sump, or a legal outlet below |
| Who digs it | An excavator, as part of new construction or an exterior waterproofing dig | A waterproofing crew with a jackhammer, no excavator | An excavator or drainage installer |
For houses, the residential code the county has adopted (2018 IRC, section R405.1) requires a drain around concrete or masonry foundations that hold back earth around a below-grade living or usable space, unless the foundation sits on well-drained sand and gravel soil, which most Wichita clay lots don't. The code's version: perforated pipe or tile laid on at least 2 inches of washed gravel or crushed rock and covered with at least 6 inches more, wrapped in filter fabric, with the stone reaching at least a foot past the outside edge of the footing and 6 inches above its top, discharging by gravity or a pump to an approved drainage system. That's the standard to hold a drain tile installation to.
A basement window well is a small version of the same problem: a hole beside the wall that has to drain somewhere. Wichita's code wants it tied to the footing drain or set on a gravel bed; see egress window well drainage.
When a yard French drain isn't enough: if the water is coming through the basement wall or up at the floor joint, a drain out in the yard won't reach it. That's a footing drain, inside or out, and the outside version means digging down to the footing; see exterior basement waterproofing digs. Either way, the water still has to go to one of the legal outlets below.
Wichita clay changes the design
Much of the ground here is clay that drains slowly and swells when it's wet. That matters for a French drain in three ways:
- The drain has to go somewhere. In tight clay, a drain can't soak water into the ground the way it can in sand. It needs a real outlet: daylight at a lower point on the lot, a dry well or pop-up emitter where the ground allows, or a sump that pumps the water out.
- Slope on the pipe. On a flat Wichita lot, finding enough fall from the wet spot to an outlet is often the hard part. Installers commonly aim for about 1% (roughly 1/8 inch per foot) or more, and long runs on flat lots can need a deeper start or a pump.
- Fabric and clean stone. Clay fines clog gravel over time. Wrapping the trench in filter fabric and using washed stone helps the drain last.
Near the Arkansas and Little Arkansas rivers, where the ground is sandier and groundwater sits closer to the surface, the problem is different: a drain may run constantly in a wet spring, so the outlet and any pump have to handle steady flow.
Tell us about the dig
(316) 869-0053Where the water is allowed to go
Getting the water off your lot without creating a problem for the street or the neighbors is part of the job:
- Storm sewer, not the street. Wichita City Code (Section 16.32) limits the storm sewer to stormwater, with listed exceptions. Uncontaminated flow from a foundation drain, footing drain, crawl space pump, or sump pump is one of those exceptions, but inside the City of Wichita it may not be discharged onto the street (City Code 10.04.060). That's spelled out on the MABCD sewer and storm sewer permit application, which is also the form for a storm sewer tap.
- Easements. Many Wichita subdivisions have drainage easements along back and side lot lines. Digging in a utility or drainage easement or the city right-of-way needs a City of Wichita permit, and blocking an easement swale can push water onto the lots upstream.
- Floodplain lots. Grading or excavating in a mapped floodplain takes a floodplain development permit through MABCD.
- Neighbors. Pointing an outlet at the property line just moves the problem. A good installer will show you where the water ends up.
Call Kansas 811 first
A typical yard French drain is 18 to 24 inches deep, which is right where gas services, electric lines, cable, and fiber run. Kansas law requires a locate through Kansas 811 at least two full working days before digging, and hand-digging within 24 inches of each side of the marks. Sprinkler lines and private lines to a shop aren't marked by 811, so point those out to the installer. More on permits and Kansas 811.
What goes into the price
French drain quotes come down to length, depth, how far the outlet is, how much stone and pipe the trench takes, whether a sump or pop-up emitter is needed, and how much lawn, landscaping, or concrete has to be cut and put back. Hauling off clay spoil adds cost too. See what drives excavation cost around Wichita, and ask each bidder to spell out the outlet: it's where cheap French drains fail.
Common questions
Does a French drain work in clay soil?
Yes, if it has a real outlet. In clay the drain mostly collects water and carries it away rather than soaking it into the ground, so the pipe needs steady fall to daylight, a dry well where the ground allows, or a sump pump.
Can I drain my French drain or sump pump into the street in Wichita?
Not onto the street inside the City of Wichita. City Code 10.04.060 bars sump and foundation-drain discharge onto the street. Clean drain water can go to the storm sewer under the code's exceptions, through a permitted connection.
Should my downspouts tie into the French drain?
Usually not. Roof water arrives too fast for a perforated drain and can back up out of it. Most installers run downspouts in a separate solid pipe.