U.S. and Mexico to send water into parched Colorado River delta
Environmental groups hail confirmation of “pulse flow”
March 03, 2014
The U.S. and Mexican governments have approved a plan to carry out a historic and vital step in advancing cooperative management of the bi-national Colorado River. The two governments, acting through the U.S. and Mexican sections of the International Boundary and Water Commission, are moving forward with a pilot “pulse flow” of water into the long-depleted delta of the Colorado River, where water has not flowed regularly since 1960.
This historic event, stemming from the groundbreaking, multi-faceted Colorado River agreement negotiated between the U.S. and Mexico known as Minute 319, will help with efforts by the U.S. and Mexico to reestablish riparian habitat, providing benefits to wildlife species and communities along the Colorado River in both countries and in the Colorado River Delta region in Mexico. The pulse flow event also creates an unprecedented model for water-sharing agreements elsewhere in the Colorado River basin and beyond.
“The pulse flow is an unprecedented and unique event in the global context,” said Jennifer Pitt, director of the Colorado River Project at Environmental Defense Fund (EDF) and U.S. co-chair of the environmental work group that helped negotiate the framework agreement for the pulse flow. “This demonstrated commitment to environmental restoration is a shining example of what two nations can achieve when we work together, and will be very helpful for both governments to obtain information that becomes increasingly relevant as we face droughts with more frequency, not only in the Colorado River basin but also in other watersheds.”
Starting on March 23, 2014, the United States and Mexico will release some 105,000 acre-feet—approximately 0.7% of the annual average flow of the Colorado River—into the delta below Morelos Dam, which straddles the Colorado River on the U.S.–Mexico border. The magnitude of the pulse flow will peak for several days at a high flow, and will last for nearly eight weeks, mostly at a reduced flow rate.
“The pulse flow is a vital part of our ongoing restoration efforts,” said Francisco Zamora Arroyo, director of the Colorado River Delta Legacy Program at Sonoran Institute. “We know that relatively small amounts of water can make a big difference in the health of the delta region.”
A binational team of scientific experts from U.S. and Mexican federal agencies and universities, as well as from the Sonoran Institute, The Nature Conservancy and Mexico-based Pronatura Noroeste, will be monitoring the event to determine its impacts and learn how water can stimulate river health.
“Some 380 bird species are expected to benefit from this return of water to the delta,” said Osvel Hinojosa, Water and Wetlands Program Director at Pronatura Noroeste, and Mexico co-chair of the environmental work group. “So will the local Mexican farming communities that long-ago watched the Colorado River delta dry up.”
Signed in November 2012, Minute 319 provides numerous benefits for water users throughout the Colorado River Basin – in seven U.S. and two Mexican states – including broader sharing of water when supplies are plentiful and in times of reduced supplies, investments in water conservation, and new opportunities to store water in upstream reservoirs such as Lake Mead – the major water storage reservoir in the Lower Colorado River Basin. The pulse flow is an important element of Minute 319—a component that both countries agreed to implement in 2014.
“This flexible approach will be particularly important given the 14-year drought in the Colorado River basin,” said Taylor Hawes, director of The Nature Conservancy’s Colorado River Program. “The agreement benefits water users throughout the Basin as well as the environment, by limiting the impact of water shortages on any one user and providing incentives for leaving water in storage while paving the way for funding future water conservation projects.”
Also under Minute 319, the Colorado River Delta Water Trust will deliver another 52,000 acre-feet (64 mcm) in “base flows” – the small but steady water supply that will sustain new habitat created by the pulse flow, in addition to trees planted at active restoration sites. A coalition of conservation organizations including EDF, Sonoran Institute, Pronatura Noroeste, The Nature Conservancy, Redford Center and National Fish and Wildlife Foundation has launched a campaign to “Raise the River” by raising the funds for the Trust to purchase rights to this water from willing sellers in the Mexicali Valley, where there is an active water rights market.
“Together, we are hoping to rewrite history to reestablish ecosystems and return some of the river’s natural amenities to local communities long deprived of a healthy environment,” said Pitt. “If we can show the long-term benefits of binational cooperation to help water users and the environment, there’s no telling what we can achieve with long-term commitments to sharing water across borders.”
Raise the River is a unique partnership of six U.S. and Mexican non-governmental organizations committed to restoring the Colorado River delta. Members include Environmental Defense Fund, Sonoran Institute, Pronatura Noroeste, The Nature Conservancy, Redford Center and National Fish and Wildlife Foundation.
To learn more about Raise the River, visit www.raisetheriver.org.
The Nature Conservancy is a leading conservation organization working around the world to conserve the lands and waters on which all life depends. The Conservancy and its more than 1 million members have protected nearly 120 million acres worldwide. Visit The Nature Conservancy on the Web at www.nature.org