To remedy your yard's waterlogged low points, regrade at least one inch of slope for every five feet of turf. If regrading doesn't work, you can build exterior perimeter drains to stop leakage. There are two types of drainage systems, surface and subsurface. Surface drainage works well for clay-based soils, while subsurface drainage is generally best suited to soils of high sand or silt content. Other factors to consider when choosing the most efficient drainage system for your yard include land configuration (natural slopes or low points) and the amount and pattern of rainfall. The typical surface system, designed to remove water that collects on top of the soil, consists of swales ? shallow open trenches ? leading to one or more dry wells that empty into a deep runoff trench dug in the lowest corner of the yard. Open trenches are the most effective way to intercept excess water puddling on the ground's surface and carry it off the landscape. Subsurface drainage systems consist of several French drains that carry off water from poorly drained areas through collection pipes linked to a deep runoff trench dug in the lowest corner of the yard. Ideal places to put French drains are the bases of slopes, along retaining walls, or any other area where water tends to collect.French drains are constructed using pea gravel or crushed rock, woven landscape fabric and a perforated, corrugated drainage pipe. Dig a three-foot-deep trench to carry water away from the area to be drained. Make certain that your trench is well sloped so that water is encouraged to move through the drain to the desired destination. Line the trench with landscape fabric to prevent the infiltration of the surrounding soil and keep the gravel porous so that water flows through easily. Then install a 4-inch or 6-inch perforated drain line at the bottom of the trench, and backfill with 4-inches of gravel and cover with drainage-friendly topsoil. Your entire system of drainpipes should connect to a 6-inch solid collection pipe that goes all the way down to the runoff trench. Regardless of whether a house is brand new or 100 years old, the yard is usually a result of how the builders left it, with low and high points occurring randomly throughout the landscape. The slope in your yard that causes a drainage problem can often contribute to the solution: each of these drainage systems depends on gravity, not pumps, to work. If a downward slope to a low-point can't be found, drywells may be required. Builders and owners alike often avoid hiring a landscape contractor but, for severe or extensive drainage problems, it's best to consult a professional before digging in.