Independent Scientists Slam Plan to Bring Desert Water to SoCal Cities

The Cadiz Valley | Chris Clarke photo

According to an independent hydrologists' evaluation of the proposed Cadiz Valley water project, project backers used flawed models and incomplete data to forecast the amount of water they could pump out of a desiccated valley in the Mojave Desert.

Cadiz project backers plan to pump up to 50,000 acre-feet of groundwater yearly for 50 years out of the hyperarid Cadiz Valley, moving the water via pipeline to coastal Southern California communities.

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Cadiz Inc., owner of about 34,000 acres in the Cadiz Valley, has teamed up with the Santa Margarita Water District, Three Valleys Municipal Water District, Golden State Water Company, Jurupa Community Services District and Suburban Water Systems to propose the project.

The independent hydrological consultants, Johnson Wright Inc. (JWI) of Lafayette, CA, were hired by the National Parks Conservation Association (NPCA) to assess claims made in the Cadiz Valley Water Conservation, Recovery, and Storage Project's Draft Environmental Impact Report (DEIR).

The key to any environmental acceptance of Cadiz Inc.'s plans is the developers' estimates of available water in the Cadiz Valley hydrological system. The DEIR contends that the majority of the water Cadiz would be removing from the desert valley -- about 32,500 acre-feet -- would otherwise be lost to evapotranspiration from Bristol and Cadiz dry lakes, and that the other 17,500 acre-feet, which would have gone into the aquifer, would be replenished by precipitation each year. In Cadiz's words:

The Cadiz Valley Water Conservation, Recovery and Storage Project is designed to capture and conserve billions of gallons of renewable native groundwater flowing beneath our property in California's Mojave Desert that is currently being lost to evaporation and salt contamination at nearby dry lakes. Through the active management of the aquifer system and a state-of-the-art groundwater protection program, the Project will reduce the loss of groundwater to evaporation from the dry lakes, put this water to beneficial use and create a reliable water supply without adversely impacting the aquifer system or the desert environment.

Since the first version of the plan was proposed over a decade ago, environmentalists have charged that Cadiz's estimates of the amount of water it could extract sustainably are wildly optimistic.

In preparing the DEIR, Cadiz relied on aquifer recharge estimates from the environmental engineering firm CH2M Hill, which provided projected figures for the annual rate of replenishment of the Cadiz aquifer based on precipitation in the Fenner and Orange Blossom Wash watersheds, the aquifer's main catchment basins. JWI challenged those estimates:

Estimating groundwater recharge in arid or semiarid regions can be a difficult and complex task. Groundwater recharge in arid and semi-arid areas is dependent on a complex set of spatial and temporal hydrologic parameters and processes dependent on local climate, land surface properties and subsurface characteristics. Indeed, surface hydrology generating recharge in arid and semi-arid areas is complex and extremely difficult to quantify using conventional methods of analysis.

Instead of using the amount of precipitation, JWI calculated the amount of water discharged from the system, which should roughly match inflow if the watershed is at equilibrium. By that standard CH2M Hill's estimate of 32,477 acre-feet per year added back into the aquifer is more than twice the actual recharge -- around 14,000 acre-feet, a figure that corresponds with earlier independent estimates.

As JWI states to provide perspective on Cadiz's recharge figures of 32,477 acre-feet:

The following recharge volumes are provided to put in perspective the amount of groundwater estimated to recharge the Fenner and Orange Blossom Watersheds:
  • This is greater than the natural recharge to the Coastal Plain of Orange County basin (29K AFY [acre-feet per year]).
  • This is greater than the combined recharge from stream flow in the [very well-watered -cc] Bishop Creek to Big Pine Creek region (and inclusive of intermediate streams) of the eastern Sierra Nevada.

JWI also points out several places in the DEIR and various supporting documents where Cadiz or its consultants either misrepresented or misinterpreted outside data, for instance referring to:

and the Davisson and Rose (2000) Maxey-Eakin recoverable water estimate of 29,815 AFY

JWI pointed out that Davisson and Rose actually estimated that "recoverable water" recharge ranged from 7,864 AFY-29,185 AFY. Cadiz had taken the maximum estimate of recharge in an extremely wet year and presented it as the figure in an average year.

Throughout the DEIR, JWI says, references to data adjustments done by consultants are left undescribed, existing studies of the Cadiz and similar areas are unmentioned if they conflict with Cadiz's preferred data, and overall estimates of the amount of water available are generally significantly higher than a cautious researcher would suggest. The comments conclude by stating that Cadiz's conceptual model of the basin's hydrology is flawed, the company has paid insufficient attention to key details of the whole system, and too few "milestones" and "decision points" are spelled out in the management plan, calling into question the company's future responsiveness to changing conditions in the basin -- despite its ostensible plans for "active management of the aquifer system."

The omission which may have the greatest impact on the Mojave Desert ecosystem involves long-term changes to the aquifer. Pumping water out of the ground creates what's called a "cone of depression," a roughly conical lowering of the water table with its deepest point at the pump, formed as water flows through rock and soil toward the pump. If a cone of depression is large enough, it can continue to grow even after pumping stops as water seeps back into the depressed area from neighboring parts of the aquifer.

A cone of depression | USGS image

Many estimates have it that pumping from the Cadiz Aquifer over 50 years could well create a cone of depression that would still be growing another 50 years after the pumping stopped, lowering the water table in the southern reaches of the Mojave National Preserve and in a number of intact wilderness areas. Lowering the water table in the desert dries up streams and seeps with devastating consequences for wildlife, as well as air quality when the landscape's vegetative cover dies off.

Which raises an issue not discussed in JWI's comments. Cadiz Inc. lauds its project as "reclaiming" water that would otherwise be "lost" to evapotranspiration. Let's assume for a moment that their figures prove to be more or less accurate, as unlikely as that may be. "Evapotranspiration" looks like a compound word, and it is. It means the sum of water put into the atmosphere either from evaporation, as when a lakebed dries up in the desert, or transpiration, which means water vapor given off by living things.

Most of the evapotranspired water in the Cadiz basin is indeed evaporated from lakebeds. But not all of it. Implying that water used by desert wildlife is a "wasted" resource is essentially the same thing as saying that river water that makes it to the ocean is "wasted," and never mind how many salmon it keeps alive along the way. The "river" in the Cadiz Basin runs into the air rather than the sea, but the argument is still the same: a disregard for the rights of living things that happen not to be human customers of Cadiz, Inc.

"[JWI's] comments do contain some uncertainty," says Seth Shteir, California Desert Field Representative for the NPCA. "Even with that uncertainty, though, it's clear that this project poses enough of a threat to the groundwater, air resources, and wildlife that we think it should be stopped."

Shteir points out that the project's implications extend far beyond the Cadiz Lake watershed. "Essentially, what Cadiz proposes to do is to take a public resource -- the desert's groundwater -- privatize it, then sell it back to us. Not only does that make no sense from an environmental perspective, but we think it's just really bad policy."

Chris Clarke is an environmental writer of two decades standing. Author of Walking With Zeke, he writes regularly at his acclaimed blog Coyote Crossing and comments on desert issues here every week. He lives in Palm Springs. Read his previous posts here.

About the Author

Chris Clarke is a natural history writer and environmental journalist currently at work on a book about the Joshua tree. He lives in Joshua Tree.
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It is incorrect and misleading to your readers to refer to this new study's authors as "independent." They were hired and paid by the National Parks Conservation Association, a longtime opponent of the Cadiz water project and an advocacy group dedicated to resisting commercial enterprises in and around national parks. It is based in Washington, D.C. and has annual revenues of $61 million.

In contrast to the modeling done by the Association's hydrologists, the studies undertaken by Cadiz are more comprehensive and, most importantly, have been peer reviewed by some of the nation's leading hydrology experts who serve on the Groundwater Stewardship Committee. This committee will continue to monitor the aquifer as the project progresses to ensure that there are no impacts to the environment.

Your article repeats unsubstantiated charges that the project would have an effect on desert flora and fauna. The aquifer in question is deep below the surface, far out of the reach of the desert ecosystem. A cone of depression is normal and expected in a wellfield, and in fact is necessary to recover water that would otherwise reach the saline brine zone. Lowering the water level in this area will have no impacts, according to the Environmental Impact Report.

The report can be downloaded by section at the Santa Margarita website - SMWD (dot) com. Reading the relevant sections will help you to report more accurately on this project.


It should be noted that Laer Pearce is a public relations consultant who lists Cadiz, Inc. as one of his clients.

This article explicitly mentioned that NPCA hired JWI. The EIR which Pearce would have us take as more authoritative was written by consultants who are — just like Pearce — in the employ of Cadiz, Inc. NPCA's mission is to safeguard the National Parks. Cadiz Inc.'s mission is to maximize their revenue by pumping water out of the Mojave Desert to sell to SoCal suburbs for many millions of dollars, in effect taking the property of the public — the 99%, if you will — and turning it into profit for the 1%.

I leave it to the reader to determine which set of assessments of the project should be viewed with greater mistrust.


As for Pearce's contention that "the aquifer in question" is "far below the reach of the desert ecosystem," he may want to think twice about whether his clients would really prefer he use that line of argument. If water does flow from the surface to the aquifer, then drawing down the aquifer will most certainly pose the risk of altering more superficial hydrological patterns, including drying up streams and seeps. But if water doesn't flow from the surface to the aquifer, as Pearce seems to suggest, then that aquifer is not being recharged at all — and Pearce's clients' EIR rests on the claim that this desert aquifer is in fact being recharged at rates that exceed those in much wetter places, like the above-mentioned northern Owens Valley.

In sum; either aquifer drawdown can affect the desert environment or the aquifer isn't being recharged. Cadiz can't have it both ways.

(As it happens even a completely isolated aquifer will affect the surface when it's drawn down, due to land subsidence. But that gets complicated.)


Lastly, Pearce misleads readers here by referring to oversight by the Groundwater Stewardship Committee as "peer review." Peer review is done by independent reviewers, generally under cloak of anonymity so as to reduce the possibility of bias. The Groundwater Stewardship Committee was convened by Cadiz in partnership with the Santa Margarita Water District. The Committee, which — far from being anonymous — has its members listed on the page linked above, seems to be composed of bonafide experts in the field of geology and hydrology. I in no way wish to impugn their integrity. But their consultation simply cannot be described honestly and accurately as "peer review," a statement with which I suspect the GSC's members would themselves agree.

Similarly, Pearce is in error when he refers to the project's Environmental Impact Report. The document downloadable from the Santa Margarita Water District's site — which I did indeed consult while writing my commentary here — is a DRAFT Environmental Impact Report. The point of a Draft EIR is to provide members of the public — including not just individuals, but also NGOs such as the NPCA and whatever scientific analysts they may hire — to identify deficiencies in the draft that are then, in theory, corrected. This process is far more likely to provide actual independent evaluation of a draft EIR than getting advice from even the most prestigious advisory committee hand-picked by the project applicant. Pearce does the public and in fact state environmental law a disservice by implying that a draft EIS is inherently more reliable than third-party evaluations of it.


Thanks for an excellent post and patient response to Mr Pearce, who indeed is the PR for the Cadiz project, though he failed to identify himself as such. Go to his website ( ) and you see the services offered include "when your issue comes down to a vote of the people or an action by a regulatory board, or you simply need perceptions changed and outcomes influenced, we have a unique set of skills that can help achieve your strategic objectives."

The "strategic objective" of Cadiz is to have us believe that mining groundwater from the Mojave desert is somehow an act of conservation. This is absurd. The National Parks Conservation Association is anything but "dedicated to resisting commercial enterprises in and around national parks." In fact, the key point emphasized by its Mojave rep at a Cadiz public hearing was that maintaining the integrity of the Mojave National Preserve was essential to supporting thousands of tourism jobs for San Bernardino County.

Moreover, the National Parks Conservation Assn would not have been forced to dedicate its scant resources spread over 50 states to pay for an independent hydrological review had Cadiz not taken pains to circumvent federal environmental review of this proposal by the US Geological Survey, whose scientists cannot be accused of bias.

Cadiz, Inc took pains to shut out the federal scientists because in an earlier 2000/2001 iteration of this project, the USGS found that it had exaggerated natural recharge of the target basin by 5 to 25 times. The new project seeks the same yields and purports to defend them using a USGS model but won't allow the survey's truly independent scientists to test the result. It has good reason to be nervous about independent review. After seeing the USGS comments in 2000 on the target valley's sustainable yield, the former lead agency on the first Cadiz project, the Metropolitan Water District of Southern California, voted against proceeding with the project. To see the earlier environmental impact study and USGS remarks, go to:

Mr Pearce contends, "The aquifer in question is deep below the surface, far out of the reach of the desert ecosystem." In fact, the water that Cadiz intends to pump in this new iteration is from the deeper carbonate aquifer and not the shallower alluvium. This key difference is not insurance against damage -- you pump groundwater and the water table falls and plants and animals dependent on it die. The difference is that when you start pumping from the deep carbonate aquifer the impact on the surface is not necessarily local and by the time it is evident, it can be far reaching -- literally across hundreds of miles -- and irreparable.

Mr Clarke's report was couth, thorough and even-handed. By way of disclosure, I am not and never have been a member of NPCA. I did not personally know its speaker at the public comment meeting held in Joshua Tree earlier this year, but I did attend the meeting and noted the comments. I have received no money or favors to comment on this at any stage and do so because in the course of researching a book about the Great Basin was appalled that Cadiz had revived a long discredited and dangerous scheme in the Mojave, which I believe to be one of the natural wonders of the world.