Catch Basins and Downspout Drainage

Nobody likes a wet basement. Are catch basins the cure?

The first line of defense to keep your basement dry is keeping water away from your foundation, and the most common source of water damage is storm water from roofs, patios and driveways. A driveway that slopes into a garage can direct storm water toward the house. Trench drain can be used to remedy this drainage problem by helping to redirect water away from the garage or living space.

However, a big contributor to the water problem can also be downspout water. Luckily, simple catch basins help reroute downspout water. Take runoff water and redirect it from your foundation by using drainage pipe and catch basins. This is going to require that you first develop a drainage plan. For this plan, you need to determine which point sources of water you have and where you want to re-route them using drainage pipe. To minimize digging, use a single “artery” through which all the other downspouts and yard basins connect. In some cases, you may find it more efficient to use two different drainage sites (i.e. front yard site and back yard site). Devise a plan that minimizes digging and disturbing your shrubs and landscape.

A Homeowner’s Drainage Plan:

1. Determine where the water originates
2. Decide where the water should discharge
3. Plan for a single pipe where all catch basins and/or channel drains connect

Taking your downspout directly into a drainage pipe is a common and economical method. This involves first digging a trench and laying drainage pipe to a lower drainage point. In some communities, the drainage pipe can run underground to the street where it exits from a hole drilled in the curb. Then hook your downspout directly into the pipe for immediate redirection of your roof water.

If you want to include surface water in your drainage plan, install a catch basin under your downspout. If situated properly, the catch basin can collect water that pools in your yard as well as water from your downspout. Catch basins can also be made to be an attractive addition to your garden downspout.

In the example shown left, the catch basin (9” x 9”) was set in concrete for stability. These basins were part of a larger “gray water” plan which directed all the downspout water to a 1300 gallon reservoir, which could later be used for an irrigation system. The overflow from the reservoir travels through perforated pipe prior before draining into a ravine.

Basins have a variety of sizes and outlet configurations that should be considered when designing your system. Basin selection will be a function of the anticipated water volume, piping depth and water source layout. Catch basin grating selection is broad. You will have color, style, application and material options that will depend on the cost and aesthetics desired on the project. Plastic grating is, by far, the least expensive option and is available in a number of colors.

Smaller basins can also be fit with brass or chrome grates, which are both attractive and costly. Cast iron grates are surprisingly affordable and available in a variety of styles for 12” x 12” basins and some small round drains.