One of the shortcomings that can ruin a perfect lawn is improper drainage. Fixing drainage problems in your yard is never as simple as installing a sump pump; the water has to go somewhere, preferably someplace about which your neighbor won’t complain. A well-drained yard uses the water it catches to save on water bills. It also keeps water away from building foundations and doesn’t let it stand in pools that destroy lawn grass and plants.
Check the drainage of your yard after a heavy rain. If there are standing pools after an hour, you have a subsurface problem. If the whole yard is still sodden or all the water runs off, perhaps the problem is your soil.
Dig down around building foundations and fill the trenches with gravel. Cover the gravel with topsoil so that the soil slopes away from the building. Model building codes state that the ground should slope 6 inches down in the first 10 feet into the yard.
Add extensions and spreaders to downspouts to distribute the runoff from roofs over a larger area away from buildings. Better still, install rain barrels or a cistern to collect all of that water for use in the garden.
Give Nature a Hand
Look for underground springs or high water tables on hydrological maps that the local government or state department of natural resources publishes. Build a pond to capitalize on natural springs or dig a “swale,” a ditch that allows drainage for heavy rains, which joins a system of drainage for your neighborhood.
Consider amending soil if rainwater only runs off. Add at least 4 inches of compost and manure to soil and work it into the top 6 inches of soil with a rotary tiller or several helpers with shovels. Your yard will need less watering and your lawn grass will improve significantly.
Explore what lies beneath areas that keep sinking. An ancient tree stump might be decaying or you might be the proud owner of a sink hole. You can remove the former or fill the latter (if it’s small) with rocks, gravel and soil.
Regrade your lawn so that it slopes gently toward the street or swales along property lines. Local codes dictate the specific fall, or slope, that is permitted but a slope should be gradual enough to keep water in the yard but sharp enough to carry water away from buildings. A fall of 1 foot for every 50 linear feet will accomplish this.
Excavate a French drain, a sloping trench that falls toward the street or a neighborhood swale, and fill it with crushed stone or lay a perforated PVC pipe on a bed of gravel. Cover the pipe with more coarse gravel and back fill with top soil.
Build a dry sink, or dewatering well. Dig a 6-foot-deep hole and fill it with rough stone, gravel and a few feet of topsoil. In many areas, these drains must be installed by licensed contractors.
Things You Will Need
- Rotary tillers
- Garden rakes
- Post-hole digger
- Crushed rock
- PVC pipe
- Top soil
- A dewatering well functions the same way as a French drain. Water in surrounding soil is drawn to the gravel because it is not saturated, then follows the gravel path (or open pipe) to drain away from the soggy area. They are both designed to fix specific problems, not an entire yard.
- Check with your local building inspector for information on the slope, or grade required in residential yards. She can also probably tell you what your building options are for other drainage projects. Always check to see whether you need building permits for projects like swales, French drains and dewatering wells before beginning.
- Some problems, like sinkholes, natural springs and wetlands, are best addressed by professionals. Learn to use the resources available in your local water department, natural resources department or university extension.