An underground gutter is designed to prevent soggy soil, keeping lawns and produce healthy….  The basic design of an underground gutter is a PVC underground downspout drain at the bottom of a gravel trench using gravity in its favor to collect and drain water. Where to dig the trench, what quality of gravel to use, and other details depend on the demands of the situation.

Successful Underground Gutter Drainage Guidelines

underground gutter drainage agricultural drain

Soil Moisture Requirements

While the foundation of a building is safest in dry soil, agricultural drainage must facilitate the preferred moisture level for the surrounding produce. While peppers and squash thrive in dry soil, peppermint and rice require muddy conditions to flourish. There are certain tools that can drain excess water while retaining a specified moisture level to the benefit of the produce.

The effectiveness of drainage is determined both grain size and thickness. Clay absorbs water while sand is more hydrophobic. Drainage trenches are generally filled with gravel pieces between 10 and 20 millimeters thick. Larger grains facilitate faster drainage. In some cases, soil is used in order to slow down the drainage and keep the surrounding area moist.

Unlike in agricultural drainage, it is vital that the soil surrounding a building remain dry. The underground downspout must always be pointed away from the foundation of any building, and should not be built less than a meter away.

Water Pooling Prevention

Proper engineering is required in gutter drainage installation in order to avoid problems later on. With 500 pounds of gravel blocking the way, it can be difficult to diagnose issues with the underground PVC pipes, so it is best to prevent them through careful planning.

One common mistake is to place the pipe output where water might pool, such as next to a rain gutter output. If water pushes its way up the pipe, it fills the trench, developing water pockets and causing the soil to grow soggy. In other words, if water flows the wrong way, the drainage trench becomes a water retention pond, and this can be extremely detrimental to the surrounding flora.

Another common mistake is creating gaps that will eventually turn into water pockets. Over time, the smallest water pocket may grow and eventually cause problems. The pipe must be installed at the base of the trench with no room for water to pool beneath it. It must be slotted to allow water to enter from all angles. Only proper installation will prevent problems from occurring.

One water pooling problem that develops over time is pipe blockage. As soil fills gaps in the pipe, the water flow is slowed. To keep the pipe clear of debris, a geofabric filter, or sock, is often installed over the pipe. The same material can be used to create a geofilter over the top of the trench, covered by a thin layer of gravel. The added benefit of this upper geofilter is that it’s easier to replace. It may not catch all the dirt, but it can be swapped out if it becomes ragged over time.

Additional Notes

To prevent damage from trucks, tractors, and heavy equipment, the drainage pipe must be buried beneath 2 feet of gravel or settled soil. If pesticides are used, letting flora grow over the top of the trench will help absorb the chemicals and prevent them from spreading into the local environment.

To have your underground gutter drain installed or modified, please reach out to Specified Fittings.