This week, we have been installing a French drain for a Victorian property in Chelmsford. A French drain is a slightly sloped trench which is filled with aggregate, that allows surface water to drain away from buildings, walls, gardens, drives etc. Although the name suggests that it comes from France, this is not true. It was actually named after Henry French, a farmer from Massachussets, who wrote about the concept in 1859 in his book about farm drainage!