We attended the 11th Water Conservation Showcase last Tuesday in San Francisco. Sponsored by local energy and water providers, the event has speakers and exhibitors dealing with conserving water. Presentation slides and videos of the presentations are now available on the above Conservation Showcase website — go to the website and click on presentations. Fagan has some great photos.
Brian Fagan, a professor of archeology at the University of California at Santa Barbara, talked about the history of people and water. He talked about many cultures that respect water and do not take it for granted: the Australian aborigines, people of Africa’s Zambezi Valley who waited for fall rains and then planted their crops the next day, people of the Fertile Crescent who used furrow irrigation 10K years ago, Egyptians who depended on the Nile River, and Romans who built aqueducts. These people used surface water.
With the Industrial Revolution, we were able to drill wells and pump water from aquifers.
Fagan talked about droughts in the American West. 5K to 6K years ago, the climate was 30% drier than today, and the water level of Lake Tahoe dropped by more than 20 feet below today’s level. Chaco Canyon, New Mexico, had nine enormous pueblos that were abandoned by 1140 AD after cycles of 5-15 dry years.
Three lessons from the past:
- Extremes of flood and drought are inevitable
- The weather of the past 150 years has been benign
- Technology is not enough to solve this water shortage
Fagan used material from The West Without Water, which he said is a “fabulous” book.
A panel of water utility representatives from San Francisco, Napa County, Contra Costa County, part of Alameda County, and East Bay MUD talked about their responses to the drought. The city of Saint Helena in Napa County will add penalties to water bills. Everyone else will rely on voluntary water use reductions. The Contra Costa rep said that half of the residential water usage is for landscaping and half of that (a quarter of the residential usage) is for lawns. The EBMUD representative said that the Sierra snowpack is 30% of normal and the water content is 12% of normal. The snowpack feeds California’s reservoirs, which are already low, so the reservoir water will probably get worse until the fall rains.
There was an afternoon panel on compost. Grasslands store a third of the world’s soil carbon. The Marin Carbon Project seeks to sequester carbon dioxide in the soil by spreading 1/2″ of compost on rangeland to increase grass. There are three demonstration farms.
Some thoughts about what we heard.
- The first speaker said we need to respect water and can’t take it for granted. I really liked The West Without Water, and I’m glad that he did too.
- The panel of water suppliers said they’ll rely on citizens to conserve, just as they’ve always done. Santa Clara County, where I live, was not represented on the water utility panel. I didn’t think to ask the panel what they think about The West Without Water and the first speaker’s presentation. My bad.
- A quarter of residential water usage is for lawns. We suburbanites continue watering our lawns while California farmers are letting fields go fallow and tearing up orchards because they don’t have enough water.