First-time ever plans for environmental benefits in the Colorado River Delta were set in motion by an agreement known as Minute 319, which was signed in 2012 by the United States and Mexico. The agreement included a science-based plan for a one-time “pulse flow” release of 105,392 acre-feet (130 million cubic meters) of water from the Morelos Dam near Yuma, Arizona, in March of 2014.
As part of a groundwater export feasibility study, the BOR was directed to assess the perennial yield of groundwater from Dixie Valley, a closed basin in western Nevada. Because Dixie Valley is a closed basin, annual groundwater recharge from surrounding mountains is lost primarily through transpiration by desert phreatophytes on the valley floor, whose roots tap the groundwater. BOR used five consecutive midsummer NDVI* (“NDVI Star”) images (a version of the Normalized Difference Vegetation Index standardized to fall between a soil background value of 0.0 and a vigorous vegetation value
The Colorado River is the principal source of water for irrigation and domestic use in Arizona, southern California, and southern Nevada.
The BOR administers the Operating Criteria and Procedures (OCAP) for the Newlands Reclamation Project, which covers approximately 61,000 acres in Nevada.
The Siletz River is located in west-central Oregon. The Siletz Tribe has requested technical assistance through BOR’s Tribal Assistance Program to evaluate hydraulic and geomorphic processes along the Siletz River. Historical aerial photos of the river will be evalutated to document geomorphological changes and the spread of invasive species over several decades. Bathymetric survey data will be combined with lidar data to build a complete topographic surface from which cross-section geometry data will be extracted and used to support hydrologic modeling of the river.