J. Román-Calleros* & J. Ramírez-Hernández** * Agricultural Sciences Institute. UABC, México * * Engineering Institute. UABC, México “Binational Water Management Planning: Consideration of Opportunities, Costs, Benefits, and Unintended Consequences – Secure and Sustainable Water in the Border Region by 2020” May 6 - 8, 2002 Rio Rico, Arizona INTERDEPENDENT BORDER WATER SUPPLY ISSUES: The Imperial and Mexicali Valleys

Interdependence... “A dependence that exists among elements of a population located in the same region that implies understanding and reciprocal cooperation.” Interdependence has been the essence of growth along the U.S.- Mexico border.

Interdependence: 154 years of binational coexistence The Colorado River is the main source of water for a binational region consisting of seven states in the American Union and two states in the Mexican Republic. Although throughout the history of both countries, the growth of the two economies has been differentiated, this has not been a decisive factor in the intense relationship.

With no document forcing anyone toward interdependence, traditions, ways of life, languages, nationalities, services, tasks and an endless number of other elements are shared in the border region. New forms of symbiotic coexistence exist between the two countries that are so different in their essence. Amazingly, interest in the Colorado River waters began at the final part of its natural course, creating doubt among upstream users and influencing the future use of the river with the creation of new water rights downstream.

* Mexicali; ** Mexicali + Tijuana + Tecate Data from Román, 2001

In the Southwestern U.S., intense population growth has caused a kind of uncontrolled water demand. In 1940, the Imperial Valley had 59,740 inhabitants, 11,000 more than Mexicali. In the year 2000, Imperial Valley population increased to 142,361 inhabitants, with a growth rate, during , of 30.2 percent, compared to a global increase of 13.6 percent for the whole State of California. Data from the U.S. Census Bureau State and County QuickFacts.

Agriculture Water Use and Efficiency Imperial 202,500 ha & 3,065 Mm 3 = $ 1.4 billions Water Productivity0.45 dlls/m 3 Water per Hectare15,135 m 3 Mexicali 207,935 ha & 2,550* Mm 3 = $ 425 millions Water Productivity0.16 dlls/m 3 Water per hectare12,263 m 3 Ratio 2.7:1 *Includes 177 Mm 3 of contaminated water in San Luis, and 700 Mm 3 of aquifer water.

Agriculture Water Efficiency Imperial/Mexicali Efficiency on both sides is not the best: Imperial Valley - 60 percent Mexicali Valley - 52 percent

Salton Sea The presence of the Salton Sea (SS) is ancestral. The temporary deviation of Colorado River water to the SS was the beginning of its recent history. Today, the SS constitutes the biggest inland lake in the State of California. 68 percent of the water that enters the SS comes from I.V. agriculture water drainage (IID), with high saline concentrations and high loads of organic matter. Boron and selenium concentrations, among others, are higher than the norm.

Salton Sea Intense deterioration of environmental quality of the SS caused thousands of birds to die during the first four months of 1998 (17,000 birds of 70 different species). The U.S. Department of Interior and other institutions prepared a Draft Environmental Impact Statement/Environmental Impact Report (DEIS/EIR) on the SS in California.

The Salton Sea is a very important part of a region, inside of a larger, complex ecosystem that it is intimately linked to the Colorado River Delta and the upper Gulf of California. The restoration of the SS should be linked to all those parts of the ecosystem and must be seen as a UNIT.

Santa Clara Sludge The Wellton-Mohawk deviation channel to the Santa Clara Sludge was part of the solution to the Colorado River water salinity problem ( ). An annual average of 160 Mm 3 of polluted water delivers 720,000 metric tons of salts in SCS. In 1973, Minute 242 (IBWC) represented a convenient exit, framed in a sense of good neighborliness. Today, the perception of this agreement has changed. Again, both governments need to look for a new creative and “good neighbor” agreement.

All-American Canal The AAC is the main conduit for delivering water and energy to Coachella and Imperial Counties, with nine small cities, 142,000 inhabitants, and 500,000 acres of agricultural lands. Over 38 km from its total longitude of 132 km, waters cross sand dunes with their high permeability which allows seepage, a very important water source for the Mexicali Valley aquifer.

All-American Canal In 1988, IID and MWDLA signed an agreement for selling 99,716 acre-feet annually to US at $28.00 per acre-feet for a period of 55 years. The sold volume of water was determined based on probable estimates of savings by lining 38 km of the AAC.

Irrigation Modules A new form of water and land management was created with the National Water Law in 1992 and the NWL Regulation in Watershed councils began to be formed at the national level starting in The objective was to create irrigation districts, with 5.8 million hectares to be administered by users. CNA gives administration responsibility to users of irrigation districts because the districts were too expensive to manage.

Irrigation Modules An irrigation module is legally constituted as a civil association of agricultural growers. They give their water and land rights to the manager of the association, who administers the available resources for their partners’ benefit. Today, the Mexicali Valley has 22 irrigation modules. In Mexico, water rights are assigned directly to each producer.

Colorado River Surplus Water For many years, California has been diverting its normal 4.4 maf apportionment. Arizona is approaching its full use and apportionment; and Nevada was expected to reach it by Adopting a new approach for the allotment of these surplus waters would seem reasonable unless the U.S. Bureau of Reclamation forgot Mexican users and the environment in the allotment. Both of them are also part of the lower basin of the Colorado River.

Water Demand vs. Population Growth Today, with the exception of the environment, all Colorado River water users know the volume they have the right to use. Communication and respect between users and government represent the guarantee that water in the future will benefit everyone, even the environment.

Water Culture –At the present time, the only viable solution is for all the water users of the Colorado River to use water rationally. –This solution can be achieved through an intense “culturization” of the entire society’s water use. –We must learn new ways to use water and recycle in a universal way that all of us should respect and accept.

Decision makers should not think only in terms of exporting water from agricultural lands. They must think of searching for new ways for everyone’s rational water use in our binational society.