Channel Drain Installation: Driveway Trench Drain Guide
A channel drain catches water along a line instead of at one spot. It is a narrow plastic trough set into the pavement with a grate on top. Put one across the bottom of a driveway, in front of a garage door or along a patio edge, and water sheeting across the surface drops in before it reaches the house.
This guide covers how to choose a channel drain for a driveway, how big to cut the trench, how to set it in concrete and how to connect the outlet. The specs come from NDS, the manufacturer of the Pro Series channel drain kits we sell. Channel drains are also called trench drains; they are the same thing.
What a Channel Drain Does
A catch basin collects water that pools at one low point. A channel drain collects water that runs across a whole edge: the width of a driveway, a garage door opening or the side of a patio. Water drops through the grate, flows along the channel and leaves through an outlet into a pipe.
Typical jobs:
- Across a driveway where it slopes toward the garage
- At the bottom of a driveway, before water runs onto the street or a walkway
- Along a patio or pool deck that drains toward the house
- At a doorway, walkway or courtyard edge
Choosing a Channel Drain for a Driveway
For a driveway, the grate has to carry the weight of the cars and trucks that cross it. NDS rates channel drains by load class; Class B covers autos and light trucks with air-filled tires at under 20 mph. Both grates in our NDS 5 in. Pro Series kits are NDS light-traffic grates.
| Spec | Galvanized steel grate (864GMTL) | Plastic grate (864) |
|---|---|---|
| Grate | #824 galvanized steel, ADA compliant | #814 light gray structural foam polyolefin, UV inhibitors |
| Traffic | Light traffic: cars and light trucks under 20 mph | Light traffic: cars and light trucks under 20 mph |
| Open area | 19.32 sq in. per foot | 23.52 sq in. per foot |
| Flow | 59.1 GPM per foot | 71.95 GPM per foot |
| Channel | 5 in. Pro Series deep profile, 4-3/4 in. deep, 1 m (39-3/8 in.) long | Same channel |
| Pack | 3 kits, about 9.8 ft | 9 kits, about 29.5 ft |
| Our price | $209.95 per 3-pack | $466.50 per 9-pack |
Each kit has one channel, two grates, grate screws, an end cap and an end outlet. Choose galvanized for a steel finish at a driveway apron or garage door. Choose plastic for long runs along patios and pool decks, or for a lower cost per foot. For forklifts or tractor-trailers, NDS makes heavier Load Star reinforced nylon and ductile iron grates; request a quote.
Planning the Run
- Put it at the low point, across the flow. The drain should sit where water collects, at a right angle to the direction it runs.
- Measure the length. Each Pro Series channel is 1 m (about 3.28 ft). Channels snap together end to end, and you can cut the last one down in 4 in. steps using the molded cut guides.
- Decide where the water goes. Plan a pipe run downhill to a pop-up emitter at daylight, an NDS Flo-Well dry well or a storm drain where allowed.
- Pick your outlet. The Pro Series has three: the end outlet (3 in. hub, with a 4 in. knockout), knockout bottom outlets for 3 in. and 4 in. sewer and drain fittings at both ends of each channel, and knockout side outlets for 3 in. pipe. Bottom and side outlets can go anywhere along the run.
- Plan the slope. Pro Series channels have a flat bottom. NDS recommends a 1% to 2% slope toward the outlet, so on long runs set the far end higher. At 1%, that is about 1 in. of fall every 8 ft.
How Deep and Wide Should the Trench Be?
NDS shows the Pro Series set in concrete for vehicle traffic, with the concrete wrapping the channel on both sides and underneath:
| NDS load class | Concrete on each side and below | Grate recess below the surface |
|---|---|---|
| Class A (pedestrian) | 4 in. | 1/8 in. |
| Class B (cars, light trucks) | 4 in. | 1/4 in. |
| Class C (heavy pneumatic tires) | 6 in. | 1/4 in. |
- Width: at least 14 in. The channel is 5-1/2 in. wide with its flange, plus 4 in. of concrete on each side.
- Depth: the 4-3/4 in. channel, the 1/4 in. grate recess and 4 in. of concrete below come to about 9 in. at the shallow end. Add depth toward the outlet for the slope.
- Concrete: NDS calls for at least 4,000 psi, vibrated to remove air pockets, with expansion and control joints to protect the channel.
Source: NDS 5 in. Pro Series concrete installation detail (PDF).
Materials and Tools
- NDS Pro Series channel drain kits (channel, grates, screws, end cap, end outlet)
- 3 in. or 4 in. PVC or corrugated pipe and fittings for the outlet run
- #3 or #4 rebar stakes, about 16 in. long, for holding the channel at height
- Concrete mix rated at least 4,000 psi; expansion joint material
- Glue for joints: NDS lists Homax Professional Welder or waterproof silicone for its polypropylene 3 in. and 5 in. channels
- Concrete saw (for existing pavement), shovel, string line, level, tape measure, hand tamper, fine-tooth saw
- Painter's tape or plastic to keep concrete off the grates
How to Install a Channel Drain in a Driveway
- Call 811 and check local rules. Have buried utilities marked before you cut or dig, and ask your town where you may discharge stormwater.
- Mark and cut. Snap a line across the driveway at the low point. For existing concrete, saw-cut a strip at least 14 in. wide and break it out.
- Dig the trench. Dig to about 9 in. deep at the high end and deeper toward the outlet for the slope. Compact the soil at the bottom.
- Assemble the run. Snap the channels together with their interlocking joints. Fit the end cap on the closed end and the end outlet where the pipe leaves, or knock out a bottom or side outlet. Cut the last channel to length on a cut guide. Glue the joints with Professional Welder or silicone; PVC solvent cement does not bond to the polypropylene channel.
- Set the height and slope. Run a string line from end to end at the slope you planned. Drive rebar stakes beside the channel and clip it in place with the molded rebar clips, so the grate will finish 1/4 in. below the driveway surface. Screw the grates in now so the channel keeps its shape during the pour.
- Connect the outlet pipe. Attach 3 in. or 4 in. pipe to the outlet with a coupling or 45° elbow, as in the NDS outlet connection detail (PDF), and run it downhill to your discharge point.
- Protect and pour. Tape or cover the grates. Pour concrete under and around the channel to at least 4 in. on each side, and vibrate or rod it so there are no voids under the channel. Add expansion joints where the new concrete meets the old slab.
- Finish and cure. Trowel the surface so it slopes slightly toward the grate. Keep traffic off until the concrete has cured.
- Test it. Run a hose across the driveway and watch the water drop into the channel and come out at the far end of the pipe.
Patios, Pool Decks, Pavers and Curves
- Patios and pool decks: without vehicle traffic, NDS says a compacted gravel base is generally enough for light-duty drains, though many installers still pour concrete around the channel for stability. Set the grate 1/8 in. below the surface.
- Pavers: NDS has a separate paver installation detail (PDF). The channel still sits in a concrete bed, with the pavers butted against it.
- Asphalt: see the NDS asphalt installation detail (PDF).
- Curves: add NDS Qwik-Turn radius couplings between channels. Each one bends the run up to 6 degrees left or right, and you can link several for a tighter curve. For sharp corners, NDS makes 90° (#861) and 45° (#862) elbows.
Common Mistakes to Avoid
- Grate set flush in a driveway. NDS recesses it 1/4 in. under traffic so tires do not hit the grate edge. In foot-traffic areas, recess it 1/8 in.
- No concrete around the channel. Under cars, a channel in gravel or soil can shift and crack. The load rating depends on the concrete surround.
- Gluing with PVC cement. It will not hold on polypropylene channel. Use the glue NDS lists or waterproof silicone.
- Grates left off during the pour. Wet concrete can push the channel walls in. Keep the grates screwed in and covered.
- No outlet plan. A channel with nowhere to send the water fills and overflows. Plan the pipe run before you cut.
- Too light a grate. Light-traffic grates are for cars and light trucks under 20 mph. Loading docks and heavy trucks need a higher load class.
To keep it working, lift the grates now and then, clear out leaves and grit, and flush the channel with a hose.
What a Channel Drain Costs
| Kit | Price | Length | Cost per foot |
|---|---|---|---|
| Pro Series 9-pack, plastic grates | $466.50 | about 29.5 ft | about $15.80 |
| Pro Series 3-pack, galvanized grates | $209.95 | about 9.8 ft | about $21.42 |
| Qwik-Turn radius couplings, 9-pack | $64.15 | 9 couplings | about $7.13 each |
Prices as of September 24, 2026. Shipping is $29.99 per galvanized 3-pack and $90 per 9-pack, and orders over $2,000 ship free. Concrete, pipe and labor depend on your site, so we do not quote them.
Which Channel Drain Kit Should I Buy?
- NDS 864 Pro Series kit, galvanized grate, 3-pack: driveway aprons, garage doors and parking pads. About 9.8 ft per pack.
- NDS 864 Pro Series kit, 9-pack: patios, pool decks, walkways and long runs. About 29.5 ft per pack at the lowest cost per foot.
- NDS 864 radius couplings, 9-pack: curves around patios, pools and planters.
- NDS 12 in. catch basin kit: where water pools at one point instead of running along an edge.
Frequently Asked Questions
Is a channel drain the same as a trench drain?
Yes. The two names mean the same thing: a long, narrow channel set flush with the pavement, with a grate on top, that catches water along its whole length.
Do channel drains have to be set in concrete?
Where vehicles cross, yes. NDS load ratings assume the channel is encased in concrete, and its installation detail shows at least 4 in. of concrete below and on both sides of the Pro Series channel for car and light-truck traffic (6 in. for heavier Class C loads). For garden paths and other light, foot-traffic areas, NDS says a compacted gravel base is generally enough.
How deep should a channel drain be?
The NDS 5 in. Pro Series channel is 4-3/4 in. deep. In a driveway, add 4 in. of concrete under it, so the trench is about 9 in. deep at the shallow end and deeper toward the outlet if you slope the run. The trench should be at least 14 in. wide.
Do channel drains need to be sloped?
The water needs to fall toward the outlet. NDS recommends a 1% to 2% slope, which is about 1 in. of fall every 8 ft at 1%. Pro Series channels have a flat bottom, so you build the slope in by setting the run lower at the outlet end. Short runs can use more outlets instead, since Pro Series outlets can go anywhere along the run.
Do you need gravel under a channel drain?
Under vehicle traffic, the channel sits in concrete, not gravel. Compact the soil under the trench so the concrete has a firm base. In foot-traffic areas, a compacted gravel base can support the channel on its own.
What does a channel drain connect to?
The channel outlet connects to 3 in. or 4 in. pipe, which carries the water to a safe discharge point: a pop-up emitter at daylight, a dry well, or a storm drain where your town allows it. On the NDS Pro Series, the end outlet takes 3 in. pipe or 4 in. fittings, the bottom knockouts fit 3 in. and 4 in. sewer and drain fittings, and the side knockouts fit 3 in. sewer and drain pipe.
Can you install a channel drain in existing concrete?
Yes. Saw-cut a strip at least 14 in. wide along the drain line, break out the concrete, dig the trench, set the channel and pour new concrete around it. This is the usual way to fix water at a garage door.
How much does it cost to install a channel drain?
For NDS Pro Series material from us, the 9-pack works out to about $15.80 per foot and the galvanized 3-pack to about $21.42 per foot, before shipping. Concrete, pipe and labor are extra. Retrofitting a driveway usually means saw-cutting and concrete work, which many homeowners hire out.
More drainage guides: catch basin installation · French drain installation · dry well installation. Buying for a town, school or contractor? See municipal and contractor accounts.