January, February and March of this year were the driest ever recorded in California. And 2020, 2021 and 2022 are projected to be the driest three-year period ever recorded.
Researchers just down the road from Del Mar, at Scripps Institution of Oceanography, say this is what climate change looks like.
California has the most volatile precipitation in the United States — the last 130 years were a random pattern of years with too little rain or too much. But warmer average temperatures make dry years drier – higher evaporation rates steal water from soil, crops and forests.
Higher evaporation rates also make wet years wetter — increasing the amount of water in the atmosphere and the risk of extreme storms like Hurricane Harvey, which dropped 40 inches of rain on Houston in just four days.
How do we survive and thrive in this warmer climate? Researchers from UC Davis and Stanford have partnered with farmers and nonprofits to recharge the depleted aquifers under California’s central valley. They are moving 100 year old levees away from rivers to restore floodplains, and using existing canals to flood farmland, when river flows are high. This is a strategy for wet years.
Similarly, in Los Angeles, city workers and the nonprofit Tree People are breaking up asphalt and creating landscapes along streets and alleys that capture stormwater and recharge the aquifers below the city.
In San Francisco, the downtown headquarters for the city’s public utilities department uses 65% less water than buildings of similar size. The water from faucets and toilets flows into an onsite treatment system that mimics tidal wetlands. Plants and microbes in the soil clean the water, which is chlorinated and pumped back into the building’s toilets. The project was so successful that the city lent its engineers to developers, and many buildings later passed an ordinance requiring all new buildings to have alternative water supplies. This is a strategy for dry years.
And here in San Diego, three projects are underway that use reverse osmosis and advanced oxidation to purify recycled water and create a new, drought-proof drinking water supply. We’re following Orange County, which has done this for years, and Los Angeles is also developing this dry year strategy.
The key to these new strategies and projects is not new technology. Essentially, we are restoring and mimicking natural systems. The key is the collaboration among water utilities, universities and nonprofits. That’s where the answers are.
Ed Note: Uhrhammer has worked in public water utilities since 2001.