This recent round of storms hammering Northern California underscores the importance of having a good drainage system to remove water from your property and keep your yard and house dry. Here are a few important points when considering a residential drainage system.
1- Connect house downspouts to drainage system
The water from your roof can cause the most problems if not properly drained away from the house foundation. Often the need for sump pumps can be eliminated simply by connecting all the downspouts and draining them away from the house.
2- Determine the best type of drain for each application
Surface drains work well in hardscape installations where water can be graded to collect in a point, or in softscape areas where there are fixed points of standing water. French drains work best in areas where there is sheeting or subsurface water, or where there is not a easy location to collect water in a surface drain. A french drain is a burried line of perforated pipe in a gravel field, which collects and transports water.
3- Use the right pipe
Flexible black corrugated pipe is best used in situations with French drains when it is surrounded by gravel drainage field, and when it is covered by protective drainage fabric, or a fabric mesh sock that is placed over the pipe. Corrugated pipe does not work as well for transporting water underground over distances. The corrugations trap silt, sediment and debris which can clog up over time. PVC Drain pipe is a better choice. Its smooth interior helps water flow without backups.
4- Where does the water go?
Drainage usually flows down hill, with common outlets being either day lit through to a curb and gutter, out into a back hillside, or in a gravel dispersion field underground, where it can percolate into the soil. The objective is to get water out of sensitive areas where it will damage the house or accumulate in the landscape.