Many property owners are not concerned with yard drainage until they have a problem. Water naturally follows the path of least resistance to lower elevations and problems arise when original pathways constructed by the builder become blocked or were inadequate from the beginning. Not having suitable slopes and drains on a property to direct or divert water runoff can allow the water to find a path directly to areas where you would least want it such as foundations, under pavement, in your basement etc. Flooding basements and cracked foundations are good wake-up calls to the issue but addressing problems beforehand can save you thousands of dollars, and headaches, down the road. Drainage Medway
The two categories of water supplying a lawn are surface and subsurface. Subsurface water refers to the water below the first layer of topsoil which cannot permeate any lower due to the tightness of the soil beneath. Also known as the water table, all soil has this layer of water with differences in depth depending on the area. Although a high water table can be a problem in some areas, in general, surface water is the cause of excess subsurface water as too much surface water penetrating the ground can raise the water table. Surface water sources are rainfall and irrigation, such as sprinklers, and can be particularly troublesome in urbanized areas which contain numerous impervious surfaces.
Streets, driveways and parking lots simply leave nowhere for rainwater to go. As with a lawn, the runoff will either pool in depressions or flow to soil around the edges causing saturation in another area. When soil reaches 100% saturation, with little or no drainage to assist in excess water removal, not only do pools of water collect, but the saturated soil takes much longer to dry out. This excess water retards plant growth by decreasing aeration in the root zone and decreasing nutrient supplies. Additionally, excess water in the soil will increase freezing damage in the winter months. Having proper drainage on your property will prevent water from collecting around your building or home foundations, minimize soil erosion and help protect your vegetation from death and disease.
Surface and subsurface are the two types of drainage solutions and both are vital protections for buildings and lawns. Surface drainage refers to the natural pathway taken by the water following rain or irrigation and is achieved through gutters, downspouts, surface grates, exposed French drains and by shaping and grading your lawn to provide maximum surface water removal with minimum soil erosion. Subsurface drainage refers to pipes and drains placed in the lawn which remove excess water that has gravitated underground, either through holes in the soil or simply from soil saturation. Water travels through soil by capillary action, which is much like a paper towel – when one side gets wet, moisture will slowly travel to the dry side until the entire substance is saturated. Once the soil is saturated, subsurface French drains are needed to remove excess water. In doing so, subsurface drainage keeps plants healthy, helps soil to warm earlier in the spring and leaves less water to freeze in the winter, minimizing frost heaving damage to your home or building.