As California and the Southwest struggle through a fourth year of serious drought, San Clementeans have been asked to do their part by curtailing water use. To date, residents and businesses have responded well to the call to conserve. We’ve reduced outdoor irrigation, removed lawns, shortened showers and installed rain barrels and low-flush toilets. City government has addressed the crisis by expanding availability of reclaimed water, offering conservation rebates, and replacing non-essential lawn areas with natives and low-water-using plants.
To further conserve, the city recently halted irrigation within its landscaped medians throughout the community—with one exception—it’s still watering the trees. While grass and shrubs in the medians go dry, the city is keeping trees alive by swaddling trunks with bags of reclaimed water that drip slowly into the soil. This is a good policy.
But why not let the trees die too?
In answer, just look to Australia, which suffered through the catastrophic 12-year Millennium Drought (1997 to 2010), also known as “the Big Dry.” As the drought worsened, Australians in places like Brisbane dramatically reduced water consumption per capita from 80 to 32 gallons per day with similar results in other cities. (For comparison, San Clemente’s residential per capita use in June 2015 was 96 gallons). But in its zeal to save water, the country lost millions of trees. With this massive die off, temperatures rose to unbearable levels in populated urban areas and fire danger soared.
Belatedly, the Aussies came to appreciate the many benefits trees provide: cooling shade, absorption of heat trapping carbon dioxide, release of pure oxygen, filtration of air pollutants, food and shelter for birds and wildlife. Beauty. When at long last the rains came, Australians came to understand the role trees play in wet weather too, by diminishing flooding, erosion and recharging depleted aquifers.
In 2012 representatives from the Los Angeles nonprofit TreePeople traveled down under to learn survival techniques from drought-weary Australians. One critical message they brought home was this: share water with the trees, keep trees alive to mitigate drought conditions. Since little can be done to save trees in the wild, everything must be done to save them in populated areas.
Our State Water Resources Control Board has reinforced this advice. “Trees are important. We don’t need to lose them if we act early and water them,” said board chair Felicia Marcus in July. She said during Australia’s severe drought the city of Melbourne doubled its number of trees.
For trees in Southern California to stay healthy, how much water do they need? Here’s a practical guide from TreePeople.
Water young trees weekly, 15 to 20 gallons (three or four 5-gallon buckets).
Water mature trees once or twice a month, deep (18 inches) and slowly (a trickle from a soaker hose for one hour).
Even if the predicted El Niño arrives, rainfall will not be enough to compensate for multiple years of drought. So when the weather is dry, share your water with the trees, please.
Patricia Holloway is president of the San Clemente Tree Foundation. She has a B.S. in environmental planning from UC Davis and a master’s in city and regional planning from UC Berkeley. She can be reached at firstname.lastname@example.org.