Drainage systems are the gutter system for groundwater that channels water away from lower elevations on a property, and allows it to be dispersed and deposited in other locations. A French drain is a gravity fed system that carries water away from a garden or other area to prevent flooding and standing water, especially around flowers, plants and shrubs. It is created with a sophisticated in-ground drainage system that involves perforated pipes. When it rains, water must be channeled away from foundations, gardens and walkways.
WHY YOU NEED A FRENCH DRAIN
Whenever water pools in an undesirable location on your property, you need a French drain to reroute the standing water. Standing water in Florida can be damaging for many reasons. Mosquito's lay eggs in water; therefore, standing water contributes to the Florida mosquito population control issues, and the accompanying disease that threatens humans and animals. Standing water damages plants and creates soggy turf. Standing water in the wrong location damages our landscape, can be a nuisance, and can be a health hazard. French drains can be an attractive solution to landscape flooding issues.
DRAINS or SWALES
French drains and swales are often mistaken as the same system, and even though the concept is the same, the construction is very different. A swale is a sloped piece of land, trench or ditch filled with gravel or stones to carry water away. Water enters the gravel-filled trench, and is fed by gravity to an exit point. French drains use perforated pipes and gravel to channel water to another location.
INSTALLING DRAINS
Installing a french drain requires that you remove a layer of sod equal to the section of trench you intend to excavate. The depth and width of the trench will generally be about a foot wide and about 18 to 24 inches in depth. The trench is usually lined with a water permeable fabric. This maintains the separation of the crushed stones and the soil, and helps to prevent clogging of the pipes. A perforated PVC pipe is placed in the fabric-lined trench. The pipe is then covered with crushed rocks or stone.
Maintaining Them
French drains are relatively low maintenance; however, they are susceptible to clogging with debris over time. The water-permeable drainage fabric reduces the risk of clogging, but does not eliminate it. Sometimes land conditions change over time, requiring additional drainage pipes to handle the groundwater.
FACTS ABOUT FRENCH DRAINS
The French drain system did not originate in France. It was developed by Henry Flagg French, Assistant Secretary of the Treasury under Ulysses S. Grant. Henry Flagg French developed a passion for agriculture and published his written work, Farm Drainage in 1859. He recommended a drainage technique that he coined the "cellar drain." Today, we refer to these drainage systems as French drains. Some of the drainage systems built by French are still operable today, even though they are more than a century old.
