Some Ground Water Background

Surface water depletion from excessive ground water use has been observed over many decades in portions of California. One recent example is the Cosumnes River, where “[d]eclining fall flows are limiting the ability of the Cosumnes River to support large fall runs of Chinook salmon,” (Fleckenstein, et al. 2004) due to elevated agricultural and municipal pumping. This is a river that historically supported a large fall run of Chinook salmon, yet in the last 40 years their numbers have dropped from 5,000 to zero with an average of 600 in recent years. Id. (USFWS 1995). Indeed, “[f]all flows in the Cosumnes have been so low in recent years that the entire lower river has frequently been completely dry throughout most of the salmon migration period (October to December).” Id.

The massive ground water extractions that have decimated the Cosumnes River have not taken place in the northern Sacramento River watershed, but they have begun through the Drought Water Bank , the Glenn Colusa experimental pumping project. The programmatic planning for many more projects is already completed. The projects and plans ignore the northern Sacramento Valley, foothills, and mountains that need water not only for their own cities, residential wells, recreation, businesses, and family farms, but also for threatened and endangered species that require the indigenous aquatic and terrestrial habitat. Fourteen significant rivers and creeks (the Sacramento River, Feather River, Battle Creek, Big Chico Creek, Butte Creek, Comanche Creek, Deer Creek, Lindo Channel, Little Chico Creek, Mill Creek, Mud Creek, Rock Creek, Thomes Creek, Stony Creek) are part of the system that provide crucial habitat for native plants and wildlife, including but not limited to Chinook salmon, steelhead, the giant garter snake, countless avian species, and more. Massive proposed ground water extractions would not only drain the aquifers but would also result in the loss of stream flow, riparian habitat, and oak woodlands (Bouwer 1997). Of special significance is Butte Creek’s wild spring-run Chinook salmon, which is the largest run in the Sacramento River system. Impaired surface water flows not only impact the quantity of water for fish and habitat, but also the quality of the water from elevated temperature and the concentration of pollutants.

Butte, Colusa, Glenn, and Tehama counties are the jurisdictions above the Tuscan Aquifer that are central to all the state and federal plans to provide more water for users south of the Bay Delta. As demonstrated above, a fully charged ground water basin keeps creeks flowing and riparian vegetation vibrant. Joseph L. Sax expanded on surface water/ground water dynamics by noting that the interaction between ground water and surface water is geologically varied, complex, and unpredictable from year to year, “[d]epending on a variety of factors, such as the varied transmissivity of the material in which it is found, the varied obstacles it encounters, and the diverse gradients over which it travels in its movement through the earth. In addition, at various points in time or space, groundwater may be in hydraulic connection with a surface stream, or it may be confined, at least for some distance, beneath a quite impermeable layer.” (2002). Scientific understanding of the interactions discussed by Sax are sorely missing in the northern Sacramento River hydrologic region (Hoover 2008). Lacking sound scientific and comprehensive understanding of the region’s water dynamics, the agencies are still willing to throw caution to the wind with massive water transfers that involve hundreds of thousands of acre feet of ground water.

In spite of the lack of a scientific foundation, one principle of hydrodynamics is quite clear: excessive depletion of ground water in the northern Sacramento Valley, whether it is from water transfers or over use, will lower the water table regionally and locally and dewater creeks, streams, and the Sacramento River just as excessive surface diversions and ground water pumping did in the Owens Valley, the San Fernando Valley, the San Joaquin Valley, and the southern end of the Sacramento Valley. Such a result would not only decimate the most significant watershed in California, but it would likely obliterate what remains of the Bay Delta, the largest inland estuary in North America, and its resident and migratory species. AquAlliance seeks to halt the repetition of history.