What Is a Catch Basin? How to Install One in Your Yard

Building a Catch Basin Drainage System

1. Dig the Catch Basin Hole

   Dig a hole for the catch basin to the depth of the basin, plus another six inches for gravel. Add the gravel.

2. Dig the Trench

   Stake out the area to be trenched with the string and stakes. Then, use the trenching shovel to remove the turf and to dig the trench from the catch basin to the intended exit point. Toss the soil on a plastic sheet to avoid adding dirt and mud to the lawn.

3. Store Dirt Under Plastic Sheeting

   Mound up the dirt from the trench under plastic sheeting. Close up the sheet at the end of every workday.

   Important

   If you want to reuse the turf, store it outside of the sheeting so it can receive sun and water.

4. Run the Pipe Through the Trench

   Once you have dug the trench to at least eight inches deep, lay the 4-inch sewer pipe. Extend the pipe as far as you need.

   Warning

   When connecting the bell-end sewer pipe, the female end of the pipe (the bell) must be pointing up-grade; that is, in the direction of the catch basin.

5. Pour Gravel Around the Entry Point of the Basin

   Concentrate much of the drain gravel under and around the catch basin. Also, have a gravel bed along the first foot or two along the drain pipe.

6. Push the Pipe Into the Side of the Basin

   Other types of catch basins have a grooved ring. Gently twist the 4-inch pipe into the side of the catch basin and through the flexible sleeve. The end of the pipe sits in the grooved ring and is sealed with silicone caulk.

   Tip

   Make sure that the drain gravel is high enough to support the pipe. Avoid having the catch basin's sleeve support the pipe.

7. Pull the Pipe Into the Basin

   On the inside of the catch basin, pull the pipe inward. Make sure that the pipe extends about 3 or 4 inches. Do not have the pipe enter the basin flush with the side of the basin.

   Catch basins and pipes should be fitted tightly to be leak-free. However, some leakage is expected. This is not a pressurized system where no leakage is required. The PVC pipes do not need to be cemented.

   Drill several weep holes at the bottom of the basin to prevent water from pooling.

8. Install a Pop-Up Emitter at the End

   At the end of the pipe run, add at least 6 inches of gravel below the end of the pipe. Insert the pop-up emitter and its self-closing cap.

9. Build a Barrier Around the Drain Emitter

   A barrier around the drain emitter is not mandatory but is helpful since it keeps the gravel in place and provides a barrier against lawn and weed growth. A simple barrier can be built from one-by-eight pressure-treated lumber to roughly 18 inches square. Cut a half-circle into one side (at the bottom) so the barrier can rest on the pipe.

10. Add Gravel Around the Emitter

    Slowly pour gravel around the pop-up emitter to just below the level of the emitter's lip. Always keep the cap clear because frequent cleaning of the elbow joint is necessary.

    Backfill the trench and around the catch basin with gravel, sand, or dirt. The more gravel you can use, the better. Gravel helps water drain away faster.

When to Call a Professional

Building a yard drainage system is not complex, but it does involve a lot of earth-moving. Professionals have trenching tools that speed up the process and eliminate much of the hard labor. For more than one or two runs of trenched drainage pipe, you may want to call a professional for help.

Catch Basins vs. Other Yard Drainage Systems

Drainage systems vary based on how much water needs to be transported and how the water is flowing. For example, a catch basin makes sense at the end of a water downspout. It catches the water from a fixed point. In contrast, a French drain can handle runoff water flowing across a wider area.

French Drains

A French drain is made by digging a long trench and laying perforated pipe along the trench. Next, the pipe and trench are covered with rocks to filter out large debris, which still allows the water to percolate its way to the pipe. The water reaches the pipe and slowly seeps into the ground from the perforations along the bottom of the pipe. It is often installed on a decline to lead the water away from a home or spot that consistently has pooling.

If you live in an area with a lot of rainfall, like the Pacific Northwest, you can still install a French drain system; however, you might consider having an endpoint, like a catch basin. Heavy rain can overwhelm a French drain system, causing pooling.

Storm Drains

A catch basin is sometimes used interchangeably to mean the same thing as a storm drain, but it is only a component in a storm drain. Both do the same thing by collecting the flow of excess water from rainfall. A storm drain is typically found along the sides of roads to deal exclusively with storm runoff, usually flowing to storm sewers.

Dry Wells

A dry well is a large receptacle for unwanted water runoff. Water is collected in the well, either led there from a pipe or seepage from above. Over time, the water percolates through gravel or a porous, slowly seeping well wall, moving the water into the groundwater table.