07 Jan Background – Scientific development in the Cadiz and Fenner Valley groundwater basins
Home to the Cadiz Water Project, the Fenner Valley is located near California’s primary water transportation infrastructure – the Colorado River, the Colorado River Aqueduct and the State Water Project. Cadiz is the cog in the middle that could link these systems together for the first time via a managed groundwater basin storing and supplying water to supplement Southern California’s water supplies. When Cadiz Inc. first conceived of playing a role in California’s water supply portfolio over 20 years ago, we asked a key question: Can this be done sustainably and in concert with the environment? Unfortunately, the science about the area was limited and scientific unknowns played a role in keeping the first version of our water project from moving forward.
Over the years, volumes of science have been produced to measure and assess hydrological, geological, biological, cultural and engineering questions about the area. The passage of time has led to important technological advances too that have improved our understanding of the area and allowed the measurement of physical data, as well as the creation of new models, instrumentation, and laboratory procedures that can confirm and answer questions previously not answered.
When we first envisioned the Project, fax machines were still screeching, and the iPhone was years away. Today, what seems like light years later, we know many things about Cadiz because of scientific improvements and technological advancements:
- Fresh water extends over 1,000 feet below ground surface benath Cadiz.
- The aquifer system beneath Cadiz allows water to easily flow.
- Groundwater is naturally recharged from precipitation that fell long ago in the mountains surrounding the Valley.
- Over 10 billion gallons of groundwater per year (approximately 30,000 acre-feet) is evaporating and leaving the system at the saline dry lakes that lie at the lowest point of the watershed.
- Agricultural use of groundwater at Cadiz has not resulted in any significant, sustained drawdown of groundwater levels in the Valley.
- The dry lake playas at the base of the watershed are comprised of calcium chloride, and the surface was never permanently wet, so it binds when dewatered and doesn’t create fugitive dust
- The root zones of plants and the reach of animals in the area do not extend to the groundwater table, which is more than 150 feet below ground surface.
One topic of scientific and hydrological questioning that has persisted throughout the permitting process relates to natural mountain springs in the upper elevations of the watershed. Natural springs and man-made springs occur in the Mojave Desert in the upper elevations of the Fenner Valley watershed and other watersheds where groundwater has found an outlet to the surface. The National Parks Service has described their occurrence in the area where the Project is located:
“Most springs and seeps in the Mojave National Preserve are located along the southwest–northeast trending spine of mountains that includes the Granite, Providence, New York, and Castle mountains. They discharge from aptly named perched aquifers, which occur above the regional water table often on a valley wall or hillside, and are primarily “filled” or recharged by rain and snow melt. Because recharge comes from local precipitation, the number of springs and seeps might vary throughout the year, as well as from year to year…While unlikely to be affected by groundwater pumping from local basin aquifers, Mojave’s springs and seeps are sensitive to variable precipitation and can go dry in a multiyear drought.”
The closest natural spring to the Cadiz Water Project’s wellfield is Bonanza Spring, which occurs in the Clipper Mountains. It is 11 miles away from the wellfield and about 1,400 feet higher in elevation than the water table at Cadiz. It provides habitat and a water source to desert wildlife, including bighorn sheep.
During the Project’s extensive government review and approval process, scientists concluded that any groundwater use in the Fenner Valley was too distant from Bonanza Spring to have any significant adverse impact. Provisions of San Bernardino County’s groundwater management plan were enhanced to ensure any potential for impact was addressed and mitigated.
But in 2018, three conflicting bodies of work were released from different sources providing opportunity for further speculation and uncertainty:
1. Cadiz-sponsored structural geology expert Miles Kenney, Ph.D. conducted a months-long study of Bonanza Spring, including extensive field mapping. He identified two convergent fault zones that intersect at Bonanza Spring and are blocking, or damming, upstream groundwater flowing in fractured bedrock above the spring. Based on the physical data points observed, he concluded that the long-term source of water to Bonanza Spring comes from above the spring and is independent of, and not influenced by, conditions in the alluvial aquifer at the Cadiz area miles below. Dr. Kenney’s work was peer-reviewed by 11 experts, and this group of experts summarized it would be “impossible” for project operations to adversely affect Bonanza Spring.
2. Scientists funded by project opponents – environmental NGOs that have litigated against the Project since 2012 – published two studies that allege the chemical composition of the water at Bonanza Spring indicates a connection between groundwater at Cadiz and groundwater in the spring. Citing this chemical marker, an opponent-sponsored scientist raised concerns that pumping at Cadiz could lead to adverse impacts on flows in the Spring, and ultimately on area wildlife. However, the study suggested continued monitoring and did not articulate how or why the Project’s already approved monitoring and mitigation measures were insufficient.
3. The Project’s CEQA lead agency, the Santa Margarita Water District, sponsored University of Nevada, Las Vegas hydrology professor David Kreamer Ph.D., a desert springs expert often relied upon by the Bureau of Land Management, to review the various studies. Dr. Kreamer cited irregularities in the chemistry data published in the project opponents’ studies, discrediting the conclusions of their studies. The Project’s permitting agencies concluded the groundwater management plan remained the best method for addressing this issue, publishing an Addendum to the Final Environmental Impact Report in 2019. https://www.fvwa.org/wp-content/uploads/2019/06/Final-EIR-Addendum.pdf.
The study sponsored by Three Valleys MWD, which is now underway, is expected to definitively answer any remaining questions about springs in the watersheds surrounding Cadiz by including extensive field work and data capture, which is available for public review. To follow the process or participate, bookmark: – www.bonanzaspringstudy.org.