Connecting the Dots ~ Fred Allebach

Fred Allebach Fred Allebach is a member of the City of Sonoma’s Community Services and Environmental Commission, and an Advisory Committee member of the Sonoma Valley Groundwater Sustainability Agency. Fred is a member of Sonoma Overlook Trail Stewards, as well as Sonoma Valley Housing Group and Transition Sonoma Valley.

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Foxtail Pines and State Water Policy

Posted on August 1, 2016 by Fred Allebach

“Signatures of all things I am here to read.” James Joyce

I had the chance to go on a University of Arizona tree ring lab expedition to Sequoia National Park. The lab was gathering tree ring samples as part of a California Department of Water Resources-funded study to reconstruct past Kern River flows. Being independently poor and Sierra-experienced gave me the credentials to go along. The water tie-ins were interesting to me as a Sonoma Valley Groundwater Management Program volunteer TAC (Technical Advisory Committee) member. Here was a chance to increase my understanding of CA and local water issues.

How do Sierra foxtail pine tree rings relate to CA surface and groundwater? River flow rates in general indicate levels of shallow aquifer recharge, as most groundwater recharge happens in porous alluvial deposits along water courses. By reconstructing Kern River flows, the lab will be reconstructing the past water regime in the Tulare Basin, where a series of endorheic lakes and marshes periodically overflowed into the San Joaquin River. This lake system is now dried up due to ag diversions and it is probable that current reliance on surface aquifer wells is negligible. Upshot: in an area of high water use and ag production, CA DWR needs baseline hydrological data to figure future water policy. The U of A tree ring lab has the stature and expertise to collect and analyze recent (@ the last 10,000 years) past climate data.

Foxtail pines were the target tree species of this trip because they are long-lived, have a longer record and the rings give an accurate climate signal. The trees live at between 9000’ and 11,500’ and some have been dated at @ 2000 years old. We sampled along the southern exposure at Siberian Pass and the eastern face of Cottonwood Pass trail. Northern exposures are not good to read past rainfall fluctuations as they have more moisture overall and trees there give a uniformly wet signal. Other crew members sampled at Crabtree Meadows, Guyot Flats and Guyot Creek just west of Mt. Whitney.

Tree rings are proxy indicators of: rainfall, drought, fire, flood, the archaeological record, legal questions, atmospheric content/ pollution, frost events, river flow, temperature, and timing of events. In dendrochronology, many different trees can be used to read past climate signals. To sample tree rings, an increment borer is used to extract a small core that is then put in a straw, labeled, and processed back at the lab

Young foxtail trees were sampled for a read on the current drought, as older trees may not have put on a ring during the worst drought years but younger trees are more robust and grow regardless.

As we know from this last year’s El Nino, NorCal and SoCal rainfall are not necessarily the same. There are also state precipitation differences between the Sierra and the coast, and coast ranges.

The tree ring lab did another DWR-funded study for NorCal titled, Sacramento River Flow 1560 -1980. Ten river flow series were reconstructed, the Sacramento River, San Joaquin and 8 tributaries. Rainfall, drought, and stream flow were reconstructed. Rings from blue oaks in this study showed the most recent drought was the worst in 500 years. From the study’s abstract: “The reconstructed streamflow series shows that the historical period includes the wettest (1854-1916) and driest (1928-1937) periods of the last 400 years, but that many other periods of sustained drought or high flows have also occurred. This reconstruction correlates well with a previous reconstruction of precipitation in California, and shows varying levels of agreement with tree-ring based reconstructions of climate done elsewhere in the western U.S.”

CA DWR would like to find past climate periodicity, so as to be able to predict the future. One thing we can see here: the ramping up to the modern period in CA is predicated on an unusually wet interval, that also includes a solid drought red flag that coincided with the Dust Bowl. According to one tree ring lab research professor, the Sacramento Flow Study did not show a past climate rhythm; any periodicity was due to chance.

To extrapolate some of this to modern CA: We do know that the current CA economy is predicated on immediate past conditions, which appear from1850 to present, to have been overall wetter rather than drier. With climate change, the future is predicted to have no normal, to be likely hotter and drier, and the old patterns, be what they may, can’t be counted on to clearly predict any longer. (Thus it is foolish to essentially call off drought conservation measures and send people back to the carwash, where business is now booming. We saved all that water so people can have shiny cars? Folly.) Tree rings and other past climate signals from archaeology tell us to be very careful with water; water is the basis of all CA prosperity.

Richard Henry Dana noted in 1834, upon observing the means of production during the Mexican Rancho Period, “what an enterprising people could do with this land.” Jared Diamond noted in his book Collapse: Why Societies Choose to Succeed or Fail, that CA had all the geographic characteristics of a great civilization but lacked one thing, reliable water for municipal use and to irrigate crops. The Anglos solved that with wells, reservoirs and aqueducts, but now with the inherent vagaries of CA climate, and with our overwhelming reliance on carbon-based industrial production and its ensuing climate change, we have screwed up any “normal” water regime there may have been. Now we need to be sustainable, conserve and dial back our footprint in many ways to avoid more human-caused tragedy of the commons outcomes.

All the tech salvation in the world can’t bring more rain. Water is the most critical indicator of our population number’s ability to even be here.

If ag uses a high % of state water for a small % of overall econ output, what makes sense is to have CA ag provide for the state’s food needs before export of luxury crops (wine, almonds etc.) out of state and overseas. Then state ag water use can be justified policy-wise as providing a natural need for the population. Subsidies and incentives can be made for state-based ag, not luxury exports that only benefit the 1%, all the while local food remains unaffordable to the working class.

Substantial population growth in the Bay Area and Sonoma County are predicted, most probably with more wealthy people coming in. Wealth is an indicator correlated with higher water use and it is likely future county water conservation will have regressive aspects. The esteemed Bruce Babbitt has been brought on board by Jerry Brown ostensibly to finesse the state’s water use into the future. The foxtails call from afar on a lonely ridge in the Eastern Sierra, “don’t squander your precious water.” This message applies equally well to us in the Russian River water system along the coast. The river is it, there isn’t enough groundwater to pump indefinitely in Sonoma Valley. Our deep aquifers will not recharge at anywhere near the rate of withdrawal.

Now is the time to develop a clear view of what CA water is all about, from the Sierra foxtails to our ag economy to current water policy.

 

 

 

 




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