French drains are used to redirect surface and groundwater away from an area, usually the foundation of a house, septic tanks, retaining walls, low spots in garden areas, crawl spaces or basements and other areas susceptible to moisture accumulation.
French drains are created by digging a trench, burying a perforated pipe and covering it with gravel or rock. Water seeps into the trench and is routed to another area of the yard. This type of drainage system is used primarily to prevent ground and surface water from penetrating or damaging building foundations.
French drains operate on gravity and the trench must slope from beginning to end. The high-end of the drain is where the excess water enters the system and the low-end, or exit point is where the excess water leaves the drain system. The optimum slope for a French drain system is one percent. A good rule of thumb for calculating the slope is for every eight feet the drain must drop one inch.
If requested for aesthetic purposes, we can install a soil-rock separator and apply topsoil over it and sod at an additional charge. If drainage must drain to the street because of slope of terrain, we can install a patented pressure release valve at the curb. It looks like a round sprinkler head and sits flush with the ground and pops up and releases water over the curb when pressure builds up and retracts when finished draining.