Standing Up to Standing Water

Tackling Lawn Drainage Issues HEAD ON!

Soggy sod usually indicates a serious lawn care problem – standing water. Standing water strikes fear in the hearts of homeowners and professionals alike due its root cause, a drainage problem. Improper drainage leads to waterlogged soils that are prone to disease and compaction, which creates conditions not conducive to gardening, games or backyard barbecues.

On the surface, the solution seems logical – control the drainage issue and eliminate the standing water.  The key is finding out what is causing the water to pond. By identifying if surface drainage or internal drainage causes standing water in your yard, you can determine the best method to solve the problem.   Following are descriptions of both types of drainage issues and solutions for each.

Surface Drainage

When I'm called to sites to evaluate turf problems, my first inclination is to look at where water travels when it rains to properly evaluate surface drainage. A continuous slope on the soil surface will properly divert excess water from the lawn. By contrast, an interruption in the lawn's slope will allow water to collect, creating a prime opportunity for standing water. Think about a football field – it has a crown or slope with no interruptions to redirect excess water away from the field. If an interruption in surface drainage exists, solutions such as adding soil to low-lying areas and installing a drain may eliminate the surface interruption so water will no longer collect in the area.

Adding Soil to Low-Lying Areas

If you choose to add soil to low-lying areas to remedy the problem, be careful not to make the two most common mistakes: Adding too much soil at once (and smothering the grass) or using an incompatible soil as your filler (and further complicating the drainage). Add the soil in layers one-half inch at a time and give the grass time to grow back. If there is no grass (another distinct possibility) then build the soil up to a point where the surface drainage is adequate and in line with the rest of the area. The soil that you use should have a compatible texture. Layering finely textured soils over coarsely textured soils will hamper water infiltration, so to be safe, use a sandier soil when filling low spots to prevent such layering.

Installing a Drain

When water must be diverted from the area, installing a drain may be the best solution to eliminate standing water. To choose the drain's location, simply find the lowest point in your area, as this will be where water will collect first. Then, run a drain line to the closest point to where the water can be carried away. The water can drain into a ditch, open field or another part of the yard.

The line can have either a perforated pipe (1 - 4 inch diameter depending on the amount of water) that is placed in the bottom of the trench and then re-filled with the original soil, or the pipe can be omitted and the line can be filled with sand or gravel to the top (commonly known as a French drain). The disadvantage of a French drain is that it is often difficult to grow grass over the top of the course sand or gravel.

In the case where the installation of a drain line will not work, dig a dry well to alleviate some of the drainage problem. Find the lowest point in the area and drive a hollow steel pipe into the ground to make the well. Then, take another pipe, similar in size, with holes in its bottom third (a copper pipe or any other type "F" pipe works well) and drive it into the well. Water will collect in the drain, and the holes in the pipe will facilitate drainage into the subsoil. Know what is underneath the ground before you dig and call a local digger's hotline to have your area marked for utilities if you are not sure.

Internal Drainage

When a lawn has proper surface drainage and standing water still exists, poor internal drainage may account for the problem. Internal drainage depends on the infiltration rate of the soil, a function of the type of soil and its density (compaction level). The type of soil cannot easily be changed, but the density can be modified somewhat through core or tine cultivation.

Cultivation

Cultivating your lawn not only increases internal drainage, but relieves compaction, reduces the level of built-up dead grass (thatch) and helps maintain optimal grass growing conditions. Make sure to use an aerating machine that removes plugs of soil rather than one that punches holes in the soil. These machines are often available for rent at home warehouse centers or can be purchased at many outdoor power equipment dealerships.

By identifying the type of drainage problem that exists in your yard, you can now be confident that a solution exists. If the problem becomes too complex, hire a professional, preferably one who specializes in drainage problems. My advice is to deal with the problem early on to take pleasure in your yard while the weather permits.