Restoring Hetch Hetchy Valley requires San Francisco to invest in certain improvements to assure that not one drop of supply is lost. The magnitude of those investments is an area where there is substantial disagreement between us and the City.
Accordingly, Restore Hetch Hetchy cares deeply about sensible water policy within California and closely watches ongoing developments. We have stayed out of the most contentious battles, including the proposed tunnel(s) under the Delta and the Bay-Delta Plan, as our own battle is sufficiently challenging.
We have, however, weighed in on water policy issues from time to time. We continue to support the Community Water Center and others in the effort to provide clean water to underserved communities in the Central Valley and other areas. We supported the passage of California’s Sustainable Groundwater Management Act (SGMA) in 2014 and are closely watching its necessarily comprehensive and methodical implementation.
The purpose of SGMA is to limit the long-term overdraft of groundwater. It is critically important for future generations in all parts of California. In drought years, about 40% of the water we use comes from groundwater. If groundwater is not available, farmers will go bankrupt, cities will endure shortages and there will be extraordinary pressure to ignore environmental concerns. SGMA is a big deal — to use a technical term.
There is no place in California where groundwater is more important than Kern County. In many parts of the county (e.g. Semitropic Water Storage District) groundwater is well managed and basins are recharged. Overall, however, groundwater levels in Kern County are dropping.
SGMA defines Groundwater Service Areas (GSAs) throughout the State and requires each to show by 2020 how it plans to become sustainable. Any GSA that fails to do so can be taken over by the State - a scary and unacceptable outcome. (Sadly, full implementation need not be accomplished until 2040!)
GSAs are required to submit these plans to the State by Jan 31, 2020. As Lois Henry reports in the Bakersfield Californian “Member agencies claimed an overdraft of 90,000 acre-feet per year for the entire 3,000-square-mile Kern subbasin. Modeling has shown the number is closer to 300,000 to 350,000 acre-feet a year.”
An online skeptic made a sarcastic comment about modeling, then seriously opined “modeling might be a good tool for forecasting and planning, but virtually useless for hard numbers”. He is incorrect.
Modeling, while detailed, is conceptually pretty simple in this case. The basic equation is: total water use = surface water use + net groundwater overdraft.
Surface water use is pretty well known. Kern County principally gets water from the Kern River, the Delta (via the California Aqueduct) and the San Joaquin River (via the Friant-Kern Canal).
Total water use can be calculated crop by crop (and of course must include urban use, but that value is small in comparison). For example in 2017, Kern’s almond orchards covered about 190,000 acres of land (think of a square, 17 miles on a side). Each acre uses about 3 acre-feet, so Kern County uses about 570,000 acre-feet to grow almonds - a bit more and one and a half times the size of Hetch Hetchy Reservoir.
Similar calculations for the rest of the county’s water use provide a pretty reasonable estimate of total water use. Groundwater overdraft can then be estimated by simple subtraction.
For most of us, it seems like a no-brainer that groundwater ought to be managed sustainably. Many long-time farmers get this and agree, wanting to keep their family farms productive for generations to come. Others, however, are cultivating new land driven by short-term economics. And, as a whole, farmers don’t like regulations and have always believed that the water under their land belongs to them. It is because of these strong feelings that SGMA was passed with significant compromise and that full implementation is still 20 years out.
It is the job of the Department of Water Resources and State Water Board to look closely at groundwater use in Kern County and in all corners of California, and to provide the overdraft protection for future generations as intended by the Sustainable Groundwater Management Act. And it is up to all of us to make sure these agencies do their job.