The Short Answer: Three Different Jobs
A French drain collects or intercepts water through a permeable drainage trench, then conveys that water toward an approved outlet. Homeowners often use the name for more than one landscape arrangement, so it is safer to describe the collection trench and the outlet than to assume every system called a French drain works the same way.
A catch basin — sometimes grouped with other surface drains — collects water at a grate or area inlet. The basin is the intake. Conveyance piping and an outlet still have to be planned.
Grading changes the surface route water follows. A swale is a shallow, shaped path that keeps runoff moving on the surface instead of burying a collector first.
Site conditions can call for more than one of these in the same written scope. The comparison below is for planning. It is not a diagnosis. Request a Drainage Estimate after FDZ looks at the source, the grade, the collection points, and a workable outlet.
Swipe or scroll sideways to see all four columns, including what each approach does not solve by itself.
| Approach | What it collects or changes | Conditions worth investigating | What it does not solve by itself |
|---|---|---|---|
| French drain | Water already in the soil or entering along a slope or foundation, collected through a permeable trench and carried toward an approved outlet. | A yard that stays saturated after the surface looks only damp, seepage at a low wall, or wet soil beside a slab after rain has stopped. | A visible low spot that still needs a surface route or inlet, roof water that has not been routed away from the house, or a hardscape that traps runoff with no collection point at the surface. |
| Catch basin | Water already running on the surface, taken in at a grate or area drain and continued through conveyance piping. | Ponding in a low corner, a patio or driveway sag, or runoff that can reach one visible inlet. | Water that never reaches the inlet, a missing or undersized conveyance line, or a site with no suitable outlet. Surrounding grade that directs water toward the basin is how many inlets are meant to work, not a defect by itself. |
| Grading / swale | The surface route runoff follows on soil and landscape. Adjacent grading can move water around a slab. Changing the pitch of existing concrete is a different class of work — slab correction or a surface collector at the edge. | Yard runoff crossing a walk or drive, a swale that has filled in, or soil next to a slab that no longer falls away from it. | Surface correction may move runoff that is still on top of the ground. It may not resolve water already in the soil or seepage from below grade, and it cannot create an outlet the lot does not have. That distinction takes a look at the site. |
How These Systems Move Water
Every working system has a collection point, a conveyance or flow path, and a place for water to leave. If any of those three is missing, the work is not ready to install. Oklahoma State University Extension ties drainage problems to hydrology, soil, grading, and slope — including runoff, saturated soil, and seepage — and treats a workable outlet, plus avoiding a worse problem for a downslope neighbor, as part of the job.
The panels below are a conceptual illustration. They do not show slope, cover, pipe size, or capacity, and they do not send roof water into a perforated collector.
Text equivalent. Panel one: a French drain collects water through a permeable trench and conveys it toward an approved outlet. Panel two: surface water enters a catch basin and continues through conveyance piping to an outlet. Panel three: runoff follows a graded surface route or swale to an outlet. Roof water is not shown feeding a perforated collector. The panels do not specify slope, cover, pipe size, or capacity.
French drain
Collection: soil water enters a permeable trench
Conveyance toward an approved outlet
Catch basin
Collection: surface water enters a grate or inlet
Conveyance piping continues to an outlet
Grading / swale
Collection: runoff follows the finished surface
Flow path / swale toward an approved outlet
Three Situations Owners Often Notice
These examples are illustrations, not completed FDZ projects. A puddle, a soggy strip, or water crossing a drive does not, by itself, name the system. There is no fixed number of hours after rain that proves you need a French drain.
Water Collecting Beside a Patio
What you can observe: a low corner stays wet after rain, water sits against the slab edge, or the patio surface appears to send runoff toward the house instead of away from it.
What FDZ would need to investigate: the slab pitch, nearby downspouts, whether the soil is only wet at the surface or staying saturated, and whether a basin, a channel at the slab edge, or a grade correction can reach an approved outlet.
Approaches that might warrant consideration include a catch basin or area drain, a channel drain at a hardscape transition, or regrading if the surface route is the problem. A French drain is not the default because water is visible next to concrete.
A Side Yard That Stays Wet After Puddles Disappear
What you can observe: the surface no longer holds a puddle, but the soil stays soft, turf thins, or the strip beside a foundation or fence remains damp longer than the rest of the lot.
What FDZ would need to investigate: whether water is still entering from a slope or roof, how the lot falls, what is in the way of a trench, and whether a specified subsurface collector can actually discharge.
A French drain may belong in the conversation when water is in the soil or entering below the surface. If the strip is only a leftover low spot, grade or a surface inlet may be the first look. Adjacent patio or foundation concrete is described separately when it is part of the same written estimate.
Runoff Crossing a Driveway
What you can observe: rainwater sheets across the drive, a dip holds water in the tire path, or flow from the yard crosses the concrete and leaves the other side wet.
What FDZ would need to investigate: the driveway pitch, whether the water is yard runoff or an open ditch that belongs under the drive, and whether a surface collector, a grade change, or a crossing pipe is the right class of work.
Yard runoff and a sag in the slab are drainage and driveway questions. An open roadside or yard ditch that has to pass under the drive is a different system — driveway culvert and tinhorn installation. Excavator services apply when the same job needs a deeper cut; they do not replace the drainage assessment.
Where Downspouts and Channel Drains Fit
Roof water is a concentrated stream. Downspout drainage can carry that flow in solid pipe away from the house, or a catch basin can take it at a grate and send it into drain pipe. Neither arrangement is automatic. Collection method, conveyance, capacity, and outlet have to be evaluated together for that roof and that yard.
Water crossing concrete at a garage apron, patio edge, or walk may need a channel or trench drain rather than a yard basin. The channel is still an intake. The pipe and the outlet remain part of the same plan.
Why the Outlet Matters
Collection without a place to discharge is not a complete system. The route has to stay accessible for maintenance, leave the discharge point stable, and use an outlet that is actually allowed for that lot.
Do not assume the street, a curb opening, a neighbor's yard, or a municipal connection is an approved outlet. Public-ditch, curb, roadway, and existing-system connections need the review that applies in that jurisdiction. City of Oklahoma City drainage rules are not automatically the same as a county road or a private rural lot.
FDZ's yard-drainage offering uses daylight, pop-up emitters, swales, approved curb outlets, and approved connections to a suitable existing system when those options fit the site. We do not discharge onto a neighboring property or connect to a sanitary sewer. Pumps and dry wells are not part of this offering.
What FDZ Considers During Assessment
Source and timing of the water — when it appears, how long the soil stays wet, and whether it is roof water, surface runoff, or water already in the ground.
Existing elevations and water paths, including how the lot, slabs, and any swales already move runoff.
Existing drains and downspouts, and whether buried pipe still has an outlet.
Utilities and equipment access, so a trench or basin can be installed without guessing what is in the way.
Driveway, patio, sidewalk, and building interfaces — where water meets concrete or a foundation.
Outlet feasibility and the approvals that apply to that discharge.
Restoration and later maintenance: backfill, grading, access to grates and cleanouts, and what is included versus itemized.
Plans or specifications you already have. Conflicting notes or site conditions that do not match those notes are resolved before installation.
After that look at the site or a review of the plans you share, FDZ writes a drainage estimate for the agreed scope.
Comparison Questions Before You Request Work
Can grading solve a drainage problem without buried piping? Sometimes. If the water is still on the surface and a finished grade or swale can carry it to an approved place, buried collection may not be the first move. Surface correction may not resolve water already in the soil or seepage from below grade, and it cannot create an outlet the lot does not have. That call is made on the site, not from a photo of a wet spot.
Can French drains and catch basins be part of the same plan? Yes, when the site has both surface ponding and subsurface saturation, or when a basin feeds a line that is planned for that combined flow. Many lots need one or the other. Combined systems are written that way on purpose.
What if there is no suitable outlet? Then the work is not ready to install. FDZ will say so rather than bury a collector that has nowhere legal to discharge. Changing the collection point does not create an outlet.
Further Reading
These are the primary references used for the technical points above. Each is cited only for what it actually supports.
- Oklahoma State University Extension — Addressing Drainage Issues in the Urban Landscape (BAE-1542). Used for how drainage problems can be runoff, saturated soil, or seepage; the need for a workable outlet; routing downspouts away from the house; and not creating a worse problem for a downslope neighbor.
- NDS / ADS — Catch Basins & Grates. Used for how a catch basin collects surface water at a grate and sends it into drain pipe, and for the point that the connected pipe limits how much water the inlet can move.
Request a Drainage Estimate
If this sounds like the water problem on your lot, Request a Drainage Estimate. Include the job address, where water collects, where it appears to come from, what you notice after rain, any existing drains or downspouts, and access notes. Photos or plans you already have can go with that request. We write the estimate after looking at the site or reviewing those plans.
If your yard needs this kind of work, FDZ Construction assesses and installs yard drainage in Oklahoma City — French drains, catch basins, downspout piping, channel drains, grading or swales, and erosion protection. Driveway ditch crossings are a different system; see driveway culverts and tinhorns.