Cadiz Water Project Science

Science

CONSERVING GROUNDWATER

The Cadiz Water Project is located on approximately 35,000 acres of contiguous land under private ownership at the base of the 1,300 square mile Fenner Valley watershed (larger that Rhode Island) in the Eastern Mojave Desert.

According to comprehensive field studies, modeling and peer review, the land overlies a prolific groundwater aquifer system that holds approximately 20 million acre-feet of water, more than Lake Mead – America’s largest surface reservoir – holds today. One acre-foot is approximately 326,000 gallons of water, or enough to serve the annual water needs of two households in California.

The groundwater in Cadiz originates from snowfall and precipitation at the upper reaches of the watershed in the New York Mountains, nearly 7,300 feet above sea level, that recharges the aquifer after it falls to the earth, saturates the soil and sinks into the water table more than a thousand feet below the surface. From there this water begins a millennial journey pulled by gravity towards a 2 ½ – 3 mile narrow constriction point at the base of the watershed where Cadiz is located.

The basin at Cadiz consists principally of an alluvial, carbonate, and crystalline aquifer; more specifically, gravel-like alluvium, highly permeable dissolved-limestone carbonate rock, and fractured granitic, metamorphic, and volcanic crystalline rock. The porous and cavernous nature of this rock contributes significantly to the productivity and movement of water through the aquifer system.

As the watershed opens into an alluvial valley, the groundwater comes closer to the surface such that by the time it reaches Cadiz it can be found at 200-400 feet below the surface. Absent the Cadiz Water Project, the groundwater would continue its migration to the Bristol and Cadiz Dry Lakes and evaporate. The Dry Lakes act as a natural vacuum, pulling the groundwater up into the atmosphere.

Plants and animals do not use or rely on the groundwater in Cadiz, as it is too deep and beyond the root zone of any plant in the area. And on the Dry Lakes, where the groundwater is closer to the surface, the water quality is so hyper-saline (10 times saltier than the ocean) and corrosive, it is too dangerous for plants and animals to consume.

The Cadiz Water Project proposes to address this natural evaporation by installing wells that will intercept and rescue groundwater on its migratory pathway towards the Dry-Lakes — 100 percent of which will otherwise be lost in absence of the Project.   The capture and conservation of groundwater by the project will be monitored by an extensive groundwater management plan, approved by San Bernardino County. The plan features over 100 monitoring installations and limitations on pumping.

By actively managing the groundwater basin at Cadiz, the Project can stop the loss of groundwater, create a new water supply for beneficial use in Southern California, and also offer a new location for groundwater storage in Southern California.

The Water Project can sustainably deliver 50,000 acre-feet of water (enough for 400,000 people) every year for 50 years without causing a single-adverse environmental impact. The science behind the Project was researched, peer reviewed, subjected to the California Environmental Quality Act and permitted by the County of San Bernardino under its Desert Groundwater Ordinance, then validated in trial court 6 times and sustained on appeal, 6 times.

 

Summary of watershed and aquifer system properties:

  • 17-34 million acre-feet of groundwater in storage in alluvial aquifer system. Additional studies show that there could be another 7 million acre-feet flowing through the carbonate and crystalline rock;
  • Application of the latest 2008 USGS computer model (INFIL3.0) results in water recharge rate estimates of approximately 32,000 acre-feet per year;
  • Character of the underlying carbonate and crystalline rock units in the aquifer system greatly contributes to its productivity and movement of groundwater;
  • Freshly collected field data corroborates watershed model results;
  • Field measurement of evaporative discharge from the Dry-Lakes quantified at approximately 31,000 acre-feet per year, roughly matching recharge estimates;
  • Significant, recharging groundwater resource can be conserved so that it is not lost to evaporation.]

To view a video about the science of the aquifer system, click here.

To read a peer review of the Project’s science by Anthony Brown, principal hydrologist with Southern California water resources consulting Aquilogic, click here.