|
The Water
Challenge San
Diego County and the coastal communities of Baja California (Tecate,
Tijuana, Rosarito and Ensenada) are in serious danger of running short
of water for their growing populations.
How did this situation arise? For San Diego, the need for new sources of water arises because the traditional sources of imported water – the State Water Project and the Colorado River – can no longer accommodate increasing demand. On the contrary, supply from these sources is expected to decline. The State Water Project (SWP), which is located in northern California, serves to capture water in the north and distribute it through massive conveyance facilities across California and ultimately to San Diego through the Metropolitan Water District. SWP is presently challenged in the north by environmental obligations, including endangered species issues, and there are those who say that it cannot reliably deliver on 50% of its water commitments. For the past two decades, California has enjoyed the use of surpluses in excess of its legal entitlement to Colorado River water. But the Colorado is also subject to environmental challenges and the ever-increasing needs of the other basin states. The California Plan, a recent agreement among the basin states and the federal government, requires California over the next 15 years to reduce its intake from the Colorado River from 5.2 million acre feet to its entitlement of 4.4 million acre feet. Baja Coastal’s Water Emergency The Baja Coastal region relies on three sources of water: Colorado River water, local surface water and groundwater. Colorado River water is delivered through the Rio Colorado-Tijuana Aqueduct and its storage facilitites at Carrizo Reservoir near Tecate. The 1944 Water Treaty between the United States and Mexico guaranteed Mexico an annual supply of 1.5 million acre feet of water from the Colorado River. The aqueduct, which began operation in 1985, was built to carry a portion of this treaty water from Mexicali to Tijuana. The aqueduct is energy inefficient and lacks sufficient capacity to meet the area’s future water supply needs. Operating at full capacity in 2000, the aqueduct delivered approximately 83,000 acre feet of water, or 96% of the water consumed in the Tijuana-Rosarito area. The second source is from local runoff stored at Abelardo L. Rodriguez Reservoir. It provided no yield in 2000 due to low rainfall. The reservoir is currently empty. In years of high rainfall, it has been able to provide close to 100% of demand. The third source, groundwater wells in Tijuana and Rosarito, provided 4% of the area’s supply in 2000. To help meet short-term needs, Mexico has requested emergency delivery of their Colorado River treaty water to Tijuana through the United States. The supplies are delivered from the Colorado River, through water distribution systems in California to a connection on the Otay Mesa. U.S. agencies, including the San Diego County Water Authority, are working to satisfy Mexico’s request. The emergency connection can deliver approximately 15,000 acre feet annually. To meet the needs of the coastal region thorugh 2010, Mexican water agencies are considering expansion of deliveries through the emergency connection and evaluating construction of a parallel pipeline to the existing Rio-Colorado-Tijuana Aqueduct. This project consists of rehabilitating canals and installing additional pumps and pipeline to the first tunnel section on the aqueduct. The yield from this project would be 34,100 acre feet annually.
|
||||||||||||||||||||||||||||||