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Palo Alto Weekly

Real Estate - April 29, 2011


Rainwater harvesting can keep precious water from going down the drain

by Forrest Linebarger

After a long, wet winter, many people are breathing a sigh of relief that the bad days of drought are over. Don't count on it.

Water demand in California is rising and our sources of water are drying up. Global warming models show California will become a much drier place in our lifetimes. Not only is rain likely to decrease, but we are expected to lose up to 90 percent of our precious Sierra snowpack by the end of the century.

Water is already a big problem for the state, but a problem largely beyond public awareness. Groundwater pumping has greatly diminished our underground aquifers. Few of us are aware that over-pumping of groundwater in Santa Clara Valley during the last 70 years caused the valley floor to drop as much 15 feet. Add to that the fact that every single river in California has been dammed, decimating fish populations, including endangered Chinook salmon.

This is not your grandkid's problem. Water is a precious commodity. Sadly, you'd never know it by the way we are pouring it down the drain.

A typical household has potable water piped in from a local water supplier. Fully one-half of this potable water is used for irrigation, where potable water is unnecessary. Almost all the remainder is used for non-potable water needs in the house, where it is then flushed down the drain to our local sewage treatment plant. They spend a lot of time, money and energy treating greywater like raw sewage.

This makes no sense.

You can cut your domestic water use in half by collecting rainwater off your roof during the winter and using the water to irrigate your yard in the summer. Rainwater can be diverted from your downspouts into storage containers. Rain barrels and other relatively small storage devices can be implemented, but they tend to fill quickly and be depleted just as fast. The average roof diverts 15,000 to 45,000 gallons of rainwater a year.

The best methods involve larger above-ground or underground cisterns that hold about as much water as your landscaping needs. This water can then be used in the dry season with the use of a simple filter and a solar-powered pump.

Another great way to handle rainwater is to build a pond for storage. A clay-bottomed vernal pond can be a nice water feature in the yard and act as a wetland habitat for birds. Wetland native plants can create a visually spectacular space that will spice up your yard.

Harvesting rainwater also greatly reduces stormwater runoff, which can protect hillsides from erosion and mudslides, keep basements dry and significantly reduce pollutant buildup and sedimentation in the bay.

Water is the great giver of life; don't let it slip through your fingers.

Forrest Linebarger is CEO of VOX Design Group Inc. in Mountain View, which specializes in designing green homes in the Bay Area. He can be reached at or at 650-694-6200, ext. 11.