Tips For Proper Yard Drainage

Standing water next to your home’s foundation is trouble. It saturates the soil and can seep into basement cracks, leading to water damage and mold growth. Draining the water away from the house requires creating a sloping yard, when possible, and installing guttering to divert roof runoff. In some cases, the installation of a buried drainage system is necessary. A homeowner’s drainage options depend on the geography of the yard, building development rules and budget.

Grading the Yard

A 2 percent grade away from the foundation is adequate for most yards. This equals a 2 foot drop over a distance of 100 feet. A shallower grade will not drain as quickly and a steeper grade might be subject to erosion. During new home construction, the contractor grades the yard after the foundation is in place, but for existing homes, the homeowner may need to have topsoil delivered to raise the level of the soil around the house. The caveat when raising the yard level is that the soil should not be closer than 6 inches from the bottom of the siding. This 6 inch space is often required by local building codes to reduce the risk of wood-boring insects entering the home.

Guttering

Without guttering and downspouts, rainwater runs off the roof and can pool next to the foundation. Even if your yard has the correct grade, the force of the roof runoff from a heavy rain can dig a trench along the foundation that will hold water. Install guttering and downspouts and add downspout extensions that carry runoff at least 5 feet away from the foundation.Trench Drains and Swales

Talk to a contractor about adding swales to your yard if the existing grading already is within 6 inches of your siding. If that's your situation, it’s not feasible to raise the grade of your yard. An excavation contractor can create a series of swales, which are similar to shallow ditches, for diverting water away from the house. When your house sits at the bottom of a sloping yard, you can install a trench drain between the foundation and the yard. Water will run into the trench and run to a collection pond or to a storm sewer. Trench drains typically feature a U-shaped trough made from heavy PVC or a similar material. The contractor installs the trough with its top level with the ground and then pours concrete around the trough to stabilize it. A metal drain fits on top, which allows water to run into the trench drain.

Drainage Considerations

Check your plans with your housing association or municipal code enforcement office. Most housing developments regulate the way in which water drains. When the developer plans the subdivision, preparations are made to install storm sewers beneath the street and to form gutters that carry water to the storm sewers. Easements and property lines are also common routes for carrying water to the storm sewers. Fill dirt left in easements or a neighbor’s yard draining onto your yard can create problems. Your municipal inspector can consult the development plat to determine whether the municipality or an adjacent neighbor must address the issue. Likewise, if your yard-grading efforts create a drainage problem for your neighbor, you might be required to correct the problem.