An NDS channel drain is a surface drainage system — a long, narrow channel topped with a grate — that collects sheet water running across hardscapes like driveways, patios, and pool decks and carries it away to a drain pipe. NDS (National Diversified Sales) makes a full range of channel drains, from narrow decorative profiles to high-capacity systems, so there is a match for nearly any surface drainage need.

An NDS Pro Series channel drain capturing surface runoff.

What is an NDS channel drain?

A channel drain (the term and nds drain channel describe the same thing) sits flush with the paved surface and runs in a line across or along the area to be drained. Water flows over the surface, drops into the channel through the grate, and is carried to an outlet that connects to underground drain pipe. Because it captures water along its whole length rather than at a single point, a channel drain is ideal for wide, flat hardscapes where standing water would otherwise collect.

The NDS channel and trench drain lines

NDS makes several channel and trench drain lines, each suited to a different flow volume and setting:

• Micro Channel: about 1-1/4 inch wide, for light flows around pools, spas, patios, and walkways.
• Slim Channel: about 2-1/4 inch wide, a low-profile, decorative option for light sheet flow on hardscapes.
• Mini Channel: about 3 inches wide, a narrow trench drain that blends subtle looks with surprising strength.
• Pro Series Channel: available in 3, 5, 8, and 12 inch widths, scaling from driveways and patios up to plazas and high-flow areas.
• Spee-D Channel: a high-capacity, lightweight alternative to poured concrete trench drains.
• Dura Slope: a modular system with a built-in slope and ductile iron grates for heavy, deep applications.

Where NDS channel drains are used

Driveways and parking areas

Across the mouth of a driveway or garage apron, a channel drain stops runoff from reaching the building or pooling on the slab.

An NDS Mini Channel drain on a residential patio.

Patios and pool decks

On patios and around pools, narrower decorative lines remove light flows while blending into the hardscape.

Walkways and commercial hardscapes

Along walkways, plazas, and commercial paving, channel drains keep pedestrian surfaces dry and safe.

Choosing an NDS channel drain

Match the line to the flow and setting: light residential flows suit Micro, Slim, or Mini; driveways and larger areas suit Pro Series; the heaviest flows suit Spee-D or Dura Slope. The Channel and Trench Drain Selector can match a line and width to your project, and the full range is on the NDS channel and trench drain collection.

Installation: slope, base, and concrete surround

Most NDS channel drains install with a concrete bed, a slope to the outlet, and a concrete surround.

The NDS plastic channel lines (Micro, Slim, Mini, Pro Series, and Spee-D) install with the same core method: a leveled gravel and concrete base, a positive slope toward the outlet, and a concrete surround that locks the channel in place flush with the finished surface.

1. Excavate the trench. Dig along the drainage line wider and deeper than the channel itself, allowing room on the bottom and both sides for a concrete bed and surround (a common rule of thumb is roughly 3 to 4 inches of concrete beneath and around the channel, though you should follow the project drawings).
2. Set a slope toward the outlet. Surface drainage needs fall to move water. A widely used target is about 0.5 to 1 percent (roughly 1/8 inch of drop per foot of run), pitched toward the outlet end. On flat sites you create this by grading the trench bottom; check it with a level and string line before you commit.
3. Lay a concrete bed. Place a bed of concrete in the bottom of the trench and seat the channel into it at the right height and slope, so the top of the grate will finish flush with the surrounding hardscape.
4. Stabilize with anchor clips or stakes. Use the line's anchor clips or 6 inch profile installation stakes to hold the channel at the correct height and alignment so it does not float or shift when concrete is placed around it.
5. Pour the concrete surround. Place concrete up both sides of the channel to encase it. Keep the grate or a protective cover on during the pour so concrete does not enter and set inside the channel.
6. Finish flush. Bring the surrounding concrete or pavers level with the top of the grate so water sheets cleanly into the channel and the grate is not a trip hazard.

Getting the slope right

Slope is the single most important detail. Without fall toward the outlet, water sits in the channel instead of draining. For straight channel lines, grade the trench bottom to about 0.5 to 1 percent toward the outlet. The Dura Slope line removes this step by building a 0.7 percent slope into its stepped sections. Either way, confirm positive drainage with a level before the concrete sets, because corrections are difficult afterward.

The concrete surround

A channel drain is only as stable as the concrete around it. The channel should sit on a concrete bed and be encased on both sides so it cannot shift or float, with the grate finishing flush with the surrounding surface. The depth and strength of that surround should match the traffic: light foot traffic on a patio needs far less than a driveway or a commercial area that sees vehicles, where a thicker, reinforced surround and a load-rated grate are required. Always follow the project drawings or manufacturer guidance for the bedding and surround dimensions.

For the fiber-reinforced concrete trench drains, installation follows the same principles — an excavated trench, a concrete bed, a slope to the outlet, and a concrete surround sized for the load class — but the heavier sections and higher load ratings make these systems most common on commercial and municipal sites where engineered drawings specify the bedding and surround.

Frequently Asked Questions