A proposal to build a turnout on the All-American Canal in order to convey some of Mexico’s Colorado River water to Mexicali, Tecate, Ensenada, and Tijuana during an emergency (like another catastrophic earthquake) disrupting the existing delivery system is being considered through the Colorado River Binational Discussions process — an ongoing series of discussions between Mexican and U.S. agencies working on Colorado River water supply and water management issues
[This account is based on a briefing on the Mexico-U.S. Binational Discussions given at the San Diego County Water Authority (SDCWA) Imported Water Committee meeting last Thursday, July 28 [agenda packet]. Colorado River Program Director Halla Razak delivered the update.]
East of El Centro. The newly-lined All-American Canal is wide, deep, and swiftly flowing.
The Colorado River is the main source of water for the state of Baja California. After the river enters Mexico, an aqueduct starting in Mexicali brings water west for Tijuana and other locales.
In the aftermath of the 2010 Baja California earthquake, the aqueduct and other canals were damaged, and for a time Tijuana was in a vulnerable position. Later, looking for ways to avoid dependence solely on the single aqueduct, Mexico expressed interest in using the All-American Canal to convey some Colorado River water to Mexico during emergencies so as to provide an extra margin of supply reliability.
The idea was presented at the Colorado River Binational Discussions and a workgroup was set up to work out a plan. Members of the workgroup are:
- San Diego County Water Authority (SDCWA)
- Imperial Irrigation District (IID)
- Metropolitan Water District of Southern California (MWD)
- Southern Nevada Water Authority (SNWA)
- Central Arizona Project (CAP)
- Various Mexican government agencies
For the next year or so the workgroup will work on design, permitting, and funding. It will also work with the International Boundary and Water Commission (which oversees the 1944 treaty with Mexico regarding water deliveries between the two countries) to determine terms and conditions for implementing the project, and the Bureau of Reclamation which coordinates the Colorado River Basin States’ input to the negotiations.
Ms. Razak indicated that the workgroup is looking at a connection with 200 CFS capacity beginning at the western end of the All-American Canal, near the turnout for the Westside Main Canal.
If all goes well, it is hoped that construction could be completed in early 2014.
Although the City of San Diego isn’t a member of the workgroup, it will have some say in the project because it owns a portion of the capacity rights in the All-American Canal. That’s another story in itself — here’s a fact sheet explaining it. San Diego shoulders some expense in maintaining those capacity rights and will be looking for an agreeable financial outcome should this project be implemented.
The April 2010 Baja California earthquake, as many of us are aware, devastated Mexico’s water infrastructure in the region. An Earthquake Engineering Research Institute (EERI) newsletter said an estimated 300 km of canals were knocked out of service [link]. Details on the effects of the earthquake are documented in this EERI Reconnaissance Report.
What was the fate of the water heading toward the unusable canals? Would it just be diverted out to sea?
That brings us back to the Colorado River Binational Process. In normal times they work on long-term strategic issues but during the last year their main focus has been dealing with the impacts of the earthquake. The All-American Canal project was an idea that came recently, relatively speaking. An earlier development was a U.S. suggestion that Mexico be permitted to temporarily store up to 200,000 acre feet in Lake Mead, as summarized in this Colorado River Board report:
“…with the large magnitude earthquake that occurred in the Mexicali Valley in early April, water deliveries from a large number of the canals in the Mexicali Valley have been disrupted. To assist Mexico in coping with this situation, the United States has suggested that, in the interest of international comity and as a one-time program, Mexico would be allowed to store up to 200,000 acre-feet of water in the reservoir system in the United States this year and then be allowed to request the delivery of the stored water during calendar year 2011. [...] Mexico has considered this offer made by the United States and is proposing that this offer by the United States be incorporated into a more comprehensive deal that includes the concepts that are currently being discussed by the two countries to pursue Bi-National projects that could benefit both countries.”
As things turned out, however, the temporary storage wasn’t much needed. According to Mark Watton, Chair of the Imported Water Committee, Mexico has been slow to take advantage of that offer because the farmers, not wanting to wait for canal repairs, began digging their own diversion ditches and were able to irrigate their crops.
Mr. Watton observed that wasn’t the first time Mexican farmers were able to wrangle some extra water. He said a number of years ago (mid 90s?) the Colorado River had surplus water and about 3 million acre feet (MAF) went to Mexico that year (the U.S. treaty obligation to Mexico is 1.5 MAF). Despite doubling the usual volume of water entering Mexico, Watton recalled, not a single drop made it to the Gulf. Why? The upstream farmers captured and used all the extra water.
A short video documenting damaged and then repaired canals and other water conveyance work was also played for the committee. San Diego County Water Authority kindly gave me a copy with permission to post it here (I added the credits at the beginning).