“Whisky’s for drinkin’ and water’s for fightin’” is a colorful and insightful saying attributed to Mark Twain. In the fifth year of California’s drought, we may see this as San Francisco’s progressive reputation is tested.
California released draft rules requiring more water in the San Joaquin River by restricting water taken for agriculture and urban users. San Francisco imports its water from this watershed. “San Francisco is expected to challenge the rule, although how aggressively remains to be seen. ‘We intend to participate in that process,’ said Sheehan, the utility agency spokesman.”
Continuing my monthly posts about California’s drought, my home town of Los Altos received zero rainfall for the fourth consecutive month, about normal for us.
Above, a western gray squirrel gathers bunchgrass and blue-eyed grass for its nest. Blue-eyed grass, sisyrinchium bellum, is a California native plant bearing blue flowers in the spring.
September was the fourth consecutive month of zero rain for my home town near San Francisco. While this seems severe, our average rainfall for these four months is only a quarter inch. Our Mediterranean climate has very dry summers.
With little rain expected, our total rain since January 2013 has remained at 61% of normal for six months.
Daytime temperatures were a bit cooler than normal. Overnight temperatures were warmer, as usual.
California has a recurring water problem that’s heightened by the drought. From the San Francisco Chronicle, “On paper, California has allocated five times more water to human uses than exists in the state’s rivers.”
The San Joaquin River drains the southern half of California’s Central Valley, but the river “goes completely dry in places because farms and cities pump so much water out of it.” After a group “named the San Joaquin River the nation’s No. 1 most endangered waterway” in 2014, a KQED article showed a photo of the dry San Joaquin River. The State Water Board is expected to release a plan for the northern half of the Central Valley in 2018.
A study of lake and marine sediment provides “evidence of a persistent relationship between past climate warming, Pacific sea surface temperature (SST) shifts and centennial to millennial episodes of California aridity.” This 2016 study confirms the long (hundreds to thousands of years) cycles of rainfall discussed in The West Without Water, and this book said that the past 100 years have been wetter than usual.
It seems that rainfall and flood predictions based on the past 100 years of rainfall measurements are too brief to adequately predict the future. This would lead to weather forecasts based on this recorded history to be breached. For example, in August 2016 an unnamed storm caused a “historic, unprecedented flooding event” in the US state of Louisiana.