Besides collecting water, French drains can be utilized to distribute water for percolation in to the soil. This particular application may be selected for a number of different reasons (reduce run-off/erosion, no viable outlet, etc.) and it works in the same manner as something else you are probably familiar with…septic system field lines. However, it is for this reason that Petty’s will not connect any other drainage collection system upstream from a French drain designed to collect water. For example, connecting a downspout drainage system to a French drain surrounding the foundation is an easy way to guarantee water will enter your house.