Here is a helpful list of Do’s and Don’t complied by The California Council of Civil Engineers and Land Surveyors concerning the upkeep of your property during the rainy season. Following these guidelines will ensure that your property will stay in the best possible condition throughout this time of the year.
1. Do clean surface and terrace drains with a shovel, if necessary, and check them frequently during the rainy season. Ask your neighbors to do likewise
2. Do be sure that all drains have open outlets. Under the right conditions, this can be tested simply on a dry day with a hose. If blockage is evident, you may have to clear the drain mechanically.
3. Do check roof drains, gutters, and down spouts to be sure they are clear. Depending on your location, if you do not have roof gutter and down spouts, you may wish to install them because roofs and their wide, flat space will shed tremendous amounts of water. Without gutters or other adequate drainage, water falling from the eaves ponds against foundation and basement walls.
4. Do check all outlets at the top of slopes to be sure that they are clear and that water will not overflow the slope itself, causing erosion.
5. Do keep drain openings (weep-holes) clear of debris and other material that could block them in a storm.
6. Do check for loose fill above and below your property if you live on a slope or terrace.
7. Do watch hoses and sprinklers. During the rainy season, little, if any, irrigation is required. Over-saturation of the ground is not only unnecessary and expensive, but can cause subsurface damage.
8. Do watch for backup in interior drains and toilets during a rainy season, this may indicate drain or sewer blockage.
9. Do exercise ordinary precaution. Your house and the building site were constructed to meet certain standards that should protect against any natural occurrences, if you do your part in maintaining them.
1. 1. Don’t block terrace drains and brow ditches on slopes or at the tops of cut slopes on sloping ground. These are designed to carry away runoff to a place where it can be safely distributed. Generally, a little shovel work will remove any accumulation of dirt or other debris that clogs the drain. If several homes are located on the same terrace, it is a good idea to check with your neighbors. Water backed up in the surface drains will tend to overflow and seep into the terrace, creating less stable slopes.
2. 2. Don’t permit water to gather above or on the edges of slopes (ponding). Water gathering here will tend to either seep into the ground, loosening fill or natural ground, or will overflow on the slope and begin erosion. Once erosion is started, it is difficult to control and severe damage may result rather quickly.
3. Don’t connect roof drains and roof gutters and down spouts to subdrains. Rather, arrange them so that they will flow out onto a paved driveway or the street where the water may be dissipated over a wide surface. Subdrains are constructed to take care of ordinary subsurface water and cannot handle the overload from roofs during heavy rain. Overloading the subdrains tends to weaken the foundations.
4. Don’t spill water over slopes, even where this may seem a good way to prevent ponding. This tends to cause erosion and, in the case of fill, can eat away carefully engineered and compacted land.
5. Don’t drop loose fill slopes. It is not compacted to the same strength as the slope itself and will tend to slide with heavy moisture. The sliding may clog terrace drains below, or may cause additional damage by weakening the slope. If you live below a slope, try to be sure that no loose fill is dumped above your property.
6. Don’t discharge water into French drains close to slopes. French drains are sometimes used to get rid of excess water when other ways of disposing water are not readily available. Overloading these drains saturates the ground and, if the drains are located close to slopes, may cause slope failure in their vicinity.
7. Don’t discharge surface water into septic tanks (leaching fields). Not only are septic tanks constructed for a different purpose, but they will tend, because of their size, to naturally accumulate additional water from the ground during heavy rain. Overloading them artificially during the rainy season is bad for the same reason as subdrains and French drains, and is doubly dangerous because their overflow can pose a serious health hazard.
8. Don’t over-irrigate slopes. Naturally, ground cover of ice plant and other vegetation will require some moisture during the hot summer months, but during the wet season, irrigation can cause ice plant and other heavy ground cover to pull loose, which not only destroys the cover, but also starts serious erosion. Planted slopes acquire sufficient moisture when it rains.
9. Don’t let water gather against foundations, retaining walls, and basement walls. These walls are built to withstand ordinary moisture in the ground and are, where necessary, accompanied by subdrains to carry of excess. If water is permitted to pond against them, it may seep through them, causing dampness and leakage inside the basemen, more important, the water pressure can cause heavy structural damage to the wall.
10. Don’t try to compact backfill behind walls near slopes by flooding. Not only is flooding the least efficient way of compacting fine-grain soil, but will also undermine or tip the wall.
11. Don’t leave a hose and sprinkler remaining on or near a slope, particularly during the rainy season. This will enhance ground saturation and may cause damage.
12. Don’t block swales that have been graded around your house or the lot pad. These shallow ditches have been put there for a purpose of quickly removing water toward the driveway, street, or other positive outlet. By all means, do not let water become ponded above by blocked swales.