US: US Geological Survey scientists are studying the effects on the environment as part of a historic, bi-national collaborative effort. Results from this study will be used to assist and inform future bi-national cooperative efforts as both countries work together to protect resources on both sides of the border. The pulse flow and the need to study its effects were agreed to as part of the recently adopted Minute 319 (PDF) to the 1944 US-Mexico Water Treaty.
Research and monitoring will focus on understanding how the water moves through the Colorado River channel, how the pulse changes as it moves downstream and infiltrates through the streambed into the groundwater, evaluating sediment erosion and deposition, and patterns of new vegetation establishment. Studying these factors will help provide an understanding of why vegetation is able to thrive in some areas and not in others and information to inform decisions about future environmental flows. In addition, remote sensing technology will be used along the length of the Colorado River delta to complement on-the-ground observations.
For the study, a large pulse of water has released into the former delta of the Colorado River along the U.S.-Mexico border since 23 March. The release will continue for about eight weeks, and the rate of release will peak from 27 March. Over this period of time, 105,392 acre feet of water will be released, a volume that would fill about 52,000 Olympic sized swimming pools.