Drains
Soggy carpets, buckled floors, damp basements and flooded yards; frazzled nerves accompany rain storms for many property owners.
Over the years we have observed the following kinds of incidents:
- A homeowner was out of town for the holidays. When he came home it was raining, the furnace was out, and there was a foot of water in the basement.
- A house was built on a slab; when it rained water soaked through the walls into the closet.
- A hillside property owner found water running under the front of the house and coming out downstairs.
- Another hillside house had a long driveway going down to the house; water ran down the driveway right into the house.
- A house was built over an old spring which had been dormant for years. Then it became active.
- Neighbors up the street put in a pool; now a drainage problem exists which was not present before.
Southern California is an area of very little rainfall; but it does rain. Because of the generally arid climate many homes have been built with little or no consideration for drainage problems.
Although the Los Angeles area is in a semi-arid region, there have always been springs and streams, especially in the canyons and hills. The early native residents depended upon the natural springs and streams for their water supply. These springs and streams dry up in the summer and during prolonged drought they almost disappear. Few are active year around. Most of these water flows disappeared during construction booms because of the desirability of the surrounding property. Much of that water is now running down storm drain systems. During grading operations – establishing building pads, roads, etc. – underground courses have been disrupted and redirected, perhaps unknowingly, when construction occurred during a dry spell. A grading operation may have exposed strata that will conduct water. That strata may emerge on some other property, and then so will the water.
The best time to solve drainage problems is before or during construction. But drainage problems can be alleviated or eliminated after construction. The first step is to find possible sources of the water. A roof collects a lot of water and is the source of many basement water problems. The yard grading or the neighbor’s yard might be the source, or the whole neighborhood.
Next the water has to be collected. This starts with roof gutters and down-spouts. Water should not be allowed to come off anywhere it wants to. It should be brought down to where it can be handled. Gutters need to be inspected and cleaned periodically; they have a way of being plugged up when they’re needed the most. Catch-basins located at low, swampy spots are good collectors. Paved gutters are sometimes helpful, but only for surface water. The trickiest collection problem is sub-surface water. This can be collected by means of a “French” drain, weep drain, or subterranean drain; a drain that intercepts the water below the ground.
Finally, the water collected must be conducted away to a safe point of discharge. This usually requires underground piping, and occasionally sump pits and pumps to remove the water.
Intuitive solutions are often unproductive. Many people build a sidewalk next to the house or a little concrete curb; but such devices will not stop water that is going under a house. It helps to appreciate the volume of water to be handled. A storm that drops one inch of rain on a typical fifty by one hundred fifty foot lot has deposited over 4000 gallons of water. For most homes that is more than the water that could be used by turning on every water outlet on the property and leaving it run for three hours, or about half of the water from a typical residential swimming pool. All of that water goes somewhere. It can go over, under, around or through obstacles. Building walls, waterproofing interiors, digging trenches, or just gritting one’s teeth storm after storm are poor solutions.
