Catch Basins & Channel Drains in Lexington, KY

Point drainage for hard surfaces and low spots

A catch basin is a box set in the ground with a grate on top and a pipe leaving the bottom or side. Water on the surface flows to the grate, drops into the box, and runs out the pipe to an outlet. The box also traps sediment and debris that would otherwise go down the line, which is why it has a removable grate. A channel drain, sometimes called a trench drain, is a long, narrow version: a slotted channel set flush with a hard surface that catches water along its whole length.

These are surface-water tools. They do nothing for water in the soil; that is French drain territory. What they do well is capture concentrated runoff at a defined low point - the bottom of a driveway, the edge of a patio, a walkout basement stairwell, a lawn dish with no fall to an edge - and give it a piped route to somewhere it can leave.

Driveways, garages and patios in Lexington

Lexington's rolling Inner Bluegrass terrain means a lot of driveways slope toward the garage, and any rain over about half an inch sends a sheet of water at the door. A channel drain set across the apron just in front of the garage slab catches that sheet and carries it to the side yard. It has to be sized for the flow, set with the grate a hair below the concrete, and connected with solid pipe on a steady fall.

Patios and pool decks that were poured flat, or that have settled toward the house, are the other frequent call. A channel drain along the house side or a small catch basin at the low corner takes the water before it reaches the sill. Where a slab cannot be cut, a basin at the edge in the adjacent turf catches what runs off and does most of the job. NWS records show Lexington's wettest months coming in late spring and early summer, which is patio season, so the fix gets used.

Sizing, pipe and outlet

A grate that is too small for the surface draining to it overtops in a hard rain and might as well not be there. Basin and channel size is worked out from the contributing area and slope, and the outlet pipe is sized to carry it; four inch is the practical minimum for anything more than a small basin, six inch where a driveway or a large roof area is involved. Pipe is solid smooth-wall so it can be cleaned.

The outlet is the same conversation as every other drainage job in Fayette County: a curb outlet, a swale, a daylight point on a slope, or a pop-up emitter in a lawn area with fall. Lexington's storm sewer discharges directly to creeks without treatment, so a curb outlet is for clean stormwater only. And a basin does not drain to a sinkhole; the Kentucky Geological Survey's warning about unfiltered water reaching karst groundwater applies to a driveway's oil and grit more than to almost anything else on a lot.

Basins in the lawn and along beds

A lawn catch basin is the answer for a dish-shaped low spot on a flat lot that cannot be regraded to an edge. A basin with an atrium grate, which stands slightly above the turf so leaves do not seal it, sits at the low point and drains by solid pipe to the outlet. Multiple basins can share one trunk line. Set correctly, the grass grows right up to the grate and the spot stops ponding.

Along foundation beds, a small basin at the downspout base catches roof water and bed runoff at once and lets you clean out mulch and grit without digging. It is a cheap upgrade whenever downspout lines are being installed.