Mark L. Johnson
Water Woes XIX-New Water-Issues & Who Pays?
Updated: Jan 2
This blog covers the current state of the Colorado River water supply and the urgent need to develop new sources of water (New Water) to augment that supply.
New Water proposals utilizing desalinated sea water from the Sea of Cortez (Mexico) are examined. Also included is a discussion regarding who pays for this very expensive New Water.
If you want to skip the details, go directly to the Summary/Conclusions.
Colorado River Reality Sets In
Have you seen all the Colorado River articles and discussion lately? Looks like the water world is finally starting to realize that the Colorado River is currently over-allocated and there will be less water available due to aridification of the western United States.
You may recall that the Tortolita Alliance (TA) sent a letter to the United States Bureau of Reclamation (USBR) on 9/1/22 recommending that Colorado River delivery contracts be cut by 20% across the board. There is some indication that USBR and the water agencies are heading in that direction.
If there is a permanent Colorado River delivery cut, many water suppliers that rely heavily on Colorado River water will have to find alternative supplies. However, there are limited immediate options. Other surface water supplies are limited. Groundwater is limited by the prudent goal to maintain safe yield, i.e. water out must be balanced by water going into the aquifer. If Colorado River water allocations are reduced, a new source of water (New Water) must be found to recharge the aquifers because natural recharge will probably not be sufficient to maintain safe yield. Alternatively, New Water could be treated and delivered directly to customers.
In June 2022, the governor signed Senate Bill 1740 which created the expanded Water Infrastructure Finance Authority (WIFA). According to the Arizona Department of Water Resources (ADWR) bill summary, "WIFA is authorized to procure services for the development, acquisition, construction, improvement, or equipping of water-related facilities using a variety of project delivery methods and forms of agreement, and to enter into public-private partnership agreements that are certified by the Attorney General." WIFA will be responsible for securing the New Water for Arizona.
Arizona Desalination Proposal
Well it did not take long for an Israeli company (IDE Technologies) to get to WIFA and propose to build a 300,000 acre-feet per year (AFY) desalination plant in Mexico utilizing the Sea of Cortez as the source. The desalinated sea water would be transported via a 200-mile pipeline from the desalination facility at Puerto Peñasco (Rocky Point) through Mexico and Arizona and connect to the Central Arizona Project (CAP) west of Phoenix. See map. The capital cost for this project is estimated at $5.5 billion ($18,333/AFY). The cost of this water for the end-user is estimated to range from $2,200-$3,300/AF.
I was able to find the IDE Technologies proposal to WIFA and you can download it by clicking on the link below. The map (right) was taken from that proposal.
Several issues emerge after reviewing this out-of-the blue proposal!
There have been other New Water studies that include Sea of Cortez desalination. Two of these studies that I am most familiar with are discussed below. Now we have yet another proposal from IDE Technolgies. Arizona should not proceed with this desalination proposal or any other New Water concepts until an overall consolidated plan for New Water is developed for the southwest region and northern Mexico. This will eliminate duplication of effort and hopefully provide some economies of scale.
Other US companies should be invited to submit competing proposals after the New Water consolidated plan is adopted. It would be a tragedy to sole source a project of this magnitude and complexity prior to completing the planning.
Mexico brings another layer of complexity to New Water. Now you are dealing with another country with their own water bureacracy and environmental regulations and the probability of difficult international water negotiations.
The timeline to properly plan, design, permit and construct New Water infrastructure is decades, not years. It took Carlsbad, CA 18 years to go from from inception to on-line status for its 55 million gallon per day (MGD) desalination plant. Moreover, it was built entirely in the US.
Treatment & Blending
Sea water can be desalinated and treated to meet raw water quality standards and utilized; (1) directly for agricultural irrigation and (2) to recharge the aquifers (groundwater) and then extracted via wells with minimal treatment and used for drinking water.
Alternatively, sea water can be desalinated and further treated to meet drinking water standards and delivered directly to customers.
These treatment options must be thoroughly vetted during the planning stage outlined above. Once again, Arizona should not rely on one vendor to come up with just one New Water option.
No matter how desalinated sea water is used, the issue of blending with other water in the aquifers and within existing water infrastructure must be researched and thoroughly pilot tested early in the game.
The USBR, Lower Basin States (Arizona, California and Nevada) and associated water agencies with Colorado River contracts must be part of New Water consolidated planning, project development and implementation.
A look at the consumptive water use by the Lower Basin States and some of the larger water users in these states provides a interesting perspective on which entities currently get the most water. The 2021 USBR Colorado River Accounting Report shows the following consumptive water usage:
Water User-State/Water Agency
Consumptive Use (million acre-feet)
Imperial Irrigation District (IID)
Coachella Valley Water District (CVWD)
Central Arizona Project (CAP)
SNWA (Las Vegas)
A consolidated regional New Water plan will be more comprehensive as it will solve several water supply issues, avoid duplication of effort and hopefully solve the environmental disaster occurring at the Salton Sea (see below).
Black & Veatch-Binational Study (2020)
In 2020, Black & Veatch (engineering consulting firm) completed a comprehensive study entitled Binational Study of Water Desalination Opportunities In The Sea of Cortez. This was a joint effort by the United States (US) and Mexico to develop options for New Water that would serve both countries.
I was able to find the Black & Veatch Study Executive Summary and you can download it by clicking on the link below. The map below was taken from that document.
A detailed water demand study was completed that covered the southwestern US and the Sonora & Baja California regions of Mexico. The demand study identified a potential 1.2 million acre-feet (MAF) water supply imbalance for the study area with 1.0 MAF of that imbalance in the US.
The study also examined potential desalination and brine management technologies. Reverse osmosis with brine ocean discharge was the preferred treatment method(s).
Five opportunities (options) were evaluated. All five opportunities included desalination facilities at various locations on the eastern shore of the Sea of Cortez. See map below. Each desalination facility was rated at 100,000 AFY. For each option, desalinated sea water was transferred via pipeline to Morelos Dam in Mexico. This is where Mexico diverts its Colorado River allotment to irrigate Mexicali Valley farmland and supply the cities of Mexicali, Tecate and Tijuana. At this location, desalinated sea water would be exchanged for Colorado River water, i.e. Mexico gets the desalinated sea water and US water agencies get a portion of Mexico's Colorado River allocation which can be used anywhere in the Colorado River System.
To achieve a total supply of 200,000 AFY of desalinated sea water, combinations of two opportunities were combined with the Opportunities 2 & 5 Combination having the lower capital cost ($4.74 billion/$23,700/AF), next to lowest annual operating cost ($155.37 million) and lowest unit cost ($2,050/AF).
The Salton Sea is California's largest lake. See map below. It is an agricultural sump, i.e. agricultural drainage from the Imperial Irrigation District (IID) flows north and agricultural drainage from the Coachella Valley Water District (CVWD) flows south into the Salton Sea. There is very little natural runoff as this area only gets an average of 3 inches of rain per year. The Salton Sea has no outlet, so decades of excess fertilizer and pesticides have accumulated in the Salton Sea.
Further exacerbating the problem is the fact that agricultural drainage flow into the Salton Sea has been reduced as a result of permanent Colorado River water transfers from IID to other water agencies. The level of the Salton Sea has declined from -228 feet below sea level (bsl) in 2003 to -239 feet bsl in 2022 for a drop of 11 feet in 19 years (the Salton Sea is lower than the Pacific Ocean). The reduction in Salton Sea surface levels have expanded the shoreline playa, exposing the accumulated fertilizer salts and pesticides to the atmosphere. There are many documented cases of asthma, bloody noses and other respiratory conditions, especially with children.
The reduction in Salton Sea volume has resulted in another environmental problem. The Salton Sea salinity level has reached 60,000 parts per million (ppm). This is 1.7 times the salinity of the Pacific Ocean (35,000 ppm). The Salton Sea fish population is pretty much extinct, and for that reason, migrating waterfoul bypass the Salton Sea as there is no fish food source.
The Salton Sea is one of the worst environmental disasters in the US and it is only 300 miles from Tucson.
Whether we like it or not, the Salton Sea was created by and is part of the Colorado River system and should be included in any discussions regarding Colorado River water and New Water.
In 2018, I reviewed 11 proposals by engineering/water firms regardng a proposed Sea-to-Sea fix for the Salton Sea. The concept is to transfer sea water from the Sea of Cortez or Pacific Ocean to the Salton Sea to prevent further playa exposure and to dilute the salt concentration. Some of the proposals also included sea water desalination to be utilized for various purposes including augmenting the Colorado River water supply. Some proposals included hydroelectric and geothermal power generation to recoup some of the capital and operating costs. The capital costs ranged from $233 million to $13 billion.
In October 2021, the Salton Sea Management Program (state of Calfornia) convened an Independent Review Panel comprised of mainly PhD-types to evaluate the 11 proposals plus 7 more for a total of 18. In September 2022, the Panel published its findings which essentially discarded the 18 proposals and offered their own solution---a voluntary Colorado River exchange program with a 112,000 AFY Salton Sea remediation desalination facility at the Salton Sea. The capital cost for this option was $17 billion. I question some of the analysis and cost estimates performed for this study and will not elaborate further.
I was able to find the Salton Sea Independent Review Panel Summary Report and you can download it by clicking on the link below.
Salton Sea remediation should be part of the consolidated plan but the costs associated with the remediation should be borne by those entities responsible for the mess, i.e. the federal government, state of California and big agriculture.
Regional Solution(s) Summary
The map below shows the southwest portion of the Colorado River System in the US and Mexico. The three New Water proposals discussed above are shown in relation to the Colorado River and the existing infrastructure used to transport that water to Colorado River water contractors.
Seems to me there should be an effort that combines these New Water proposals into one consolidated plan.
As reported above, the capital cost for New Water project(s) is in the billions of dollars. The average unit capital cost of the IDE Technologies Proposal ($18,333/AFY) and the Black & Veatch-Binational Opportunity 2 & 5 Combination ($23,700/AFY) is $21,417/AFY. Using this average, a 200,000 AFY desalination facility with a 200-300 mile pipeline will cost about $4.3 billion.
The end-user cost (capital component and operating component) for the IDE Technologies Proposal ($2,650/AF) and the Black & Veatch-Binational Opportunity 2 & 5 Combination ($2,050/AF) is $2,350/AF. This is 10 times the current CAP water price of $228/acre-feet!
The cost of New Water should only be borne by new water system users that place incremental water demands beyond that of the existing water supply capacity. For example, Tucson Water customers should not be subject to any New Water costs as its water supply is sufficient for at least 80 years even assuming a 20% cut to its CAP supply. [See Tucson Water-One Water Analysis]
For water agencies without surplus non-groundwater water supplies, any new growth requiring New Water would compel developers and/or the New Water users to pay the incremental cost of New Water.
The Colorado River is currently over-allocated and there is even less water available due to aridification of the western United States.
There is some indication that USBR and the Lower Basin States water agencies are heading toward a permanent Colorado River allocation cut.
Water users with limited Colorado River water supply will be required to acquire New Water to augment existing supplies in order to serve existing and new customers.
Desalinated sea water from the Sea of Cortez appears to be the only viable New Water option and it is very expensive.
New Water development should be approached from a regional perspective with consolidated water supply planning.
The consolidated New Water plan should be implemented with competitive proposals from a variety of qualified consultants/contractors.
The timeline for planning, designing and constructing New Water desalination facilities and pipelines is decades not years, especially in a binational situation with Mexico.
Water treatment options and blending scenarios must be properly pilot tested as part of the initial planning process to ensure no water quality snafus.
The New Water consolidated regional plan must include remediation of the Salton Sea as it was created as part of the existing Colorado River system.
The costs associated with Salton Sea remediation should be borne by the federal government, state of California and big agriculture.
The capital cost for a 200,000 AFY desalination facility with a 200-300 mile pipeline is about $4.3 billion.
The end-user cost (capital component and operating component) for a 200,000 AFY desalination facility with a 200-300 mile pipeline is about $2,350/AF. This is 10 times the current CAP water price of $228/acre-feet!
The cost of New Water should only be borne by new users that place incremental water demands beyond that of the existing water supply capacity.
For water agencies without surplus non-groundwater water supplies, any new growth requiring New Water would compel developers and/or the new water users to pay the incremental cost of new water.