Experts hired by Cadiz say they are confident the pumping would not hurt Bonanza and the other springs because they are at higher elevations and get their water before it drains into the valley aquifers. "There's no way we could affect springs up there," said Terry Foreman, senior hydrogeologist and vice president of CH2M HILL, nodding toward the mountains.
Federal scientists say Cadiz has yet to prove the springs have no connection to the aquifers. "It may be true and it might not be true," said Debra Hughson, science advisor for the Mojave preserve. Regardless, she called the project an "unsustainable groundwater mining proposal."
Cadiz intends to withdraw more water every year than nature puts back in the ground, lowering the groundwater table and depleting the aquifer. By how much, and whether that will harm the fragile desert environment of nearby public lands, remain important questions.
No one really knows the rate of natural groundwater replenishment in the 1,300-square-mile area that drains toward the Cadiz operation. Scientists can only estimate it based largely on conceptual modeling that has yielded a wide range of numbers over the years.
Federal hydrologists and scientists hired by environmental groups say the natural recharge rate is at most half — and could be less than a sixth — of what Cadiz's experts say it is.
Acknowledging the dispute, the project's draft environmental report, released in December, concludes that a half century of pumping would deplete native groundwater reserves by a minimum of 3% and possibly as much as 13%, depending on natural replenishment rates and the size of the aquifer.
Nearly four centuries would have to pass before aquifer storage fully recovered from the larger decline.
Financing is another looming question. The project has a preliminary price tag of $225 million to $275 million. According to the company's latest annual report, Cadiz, which is publicly traded, is losing money on its operations and has a debt of $56.6 million.
It has so far struck option agreements to sell up to 80% of the groundwater to three investor-owned utilities and three public water districts that serve portions of Southern California, including the second largest in Orange County, Santa Margarita.
To price the supplies competitively, Cadiz is hoping for public subsidies. Those include credits from the Metropolitan Water District, state and federal grants and public financing of some or all of the capital costs of the project's most expensive component, a 43-mile pipeline that would transport water from the well field to the Colorado River Aqueduct.
Without subsidies, the options show that Cadiz water would be among the most expensive in the Southland, nearly $1,100 an acre-foot for untreated supplies. Treatment would further jack up the price. Metropolitan plans to next year charge $847 an acre-foot for treated supplies.
John Schatz, general manager of the Santa Margarita district, which has signed up for the biggest share of Cadiz water and is leading the project's environmental review process, said the price is high but Metropolitan rates are rising and the groundwater's reliability adds to its value.
Under the proposal, Santa Margarita and other customers would form a private mutual water company that would buy supplies from Cadiz and manage the operation. Mutual water companies are not regulated by the California Public Utilities Commission and members would be free to sell their water. "We certainly contemplated that in the overall approach," Schatz said.
Nor is groundwater use regulated by the state. San Bernardino County supervisors — who have received $79,500 combined in campaign contributions from Cadiz since 2007 — recently voted to give Cadiz an exemption from the county's desert groundwater ordinance, instead approving an agreement that gives the county authority to enforce the project's monitoring and management plan.
Missing from the oversight lineup are the federal agencies that manage nearby land. Cadiz argues that it does not need federal approval because its pipeline route follows an existing railroad right-of-way.
But a recent Interior Department solicitor's opinion held that railroads cannot authorize activities in their federal right-of-ways "that bear no relationship to the construction or operation of a railroad."
In a Friday letter to Interior Secretary Ken Salazar, Feinstein dismissed Cadiz's arguments that the railroad could use the pipeline to put out trestle fires and wash rail cars.
"California's Mojave Desert is a unique and special place … that must be protected," wrote Feinstein, requesting a full review of the project under federal environmental law.
PHOTOS: Mojave groundwater plan