 |
| from Bureau of Reclamation |
There has been a drought in the Colorado River Basin for the past 22 years. This combined with higher temperatures has lead to what some are calling aridification of the region. Lake Mead has seen more than 130-foot drop in the water level since the turn of the century. Water releases down river from Lake Meade and Lake Powell reservoirs are determined by the Bureau of Reclamation forecast reservoir water elevations. Plans that were developed over the past two decades lay out detailed operational rules for these critical Colorado River reservoirs. Based on projections in the study:
More than twenty years of drought, drying out of the West due to changing climate, and growing populations throughout the basin are creating a water crisis. Under the terms of the Colorado Compact the Upper Basin States must deliver 7,500,000-acre feet of water each year for the Lower Basin States and 1,500,000-acre feet for Mexico, an allotment for the tribes and an allotment to nature. The Lower Basin states of Arizona, California and Nevada were first to address their growing problem by creating a Drought Contingency Plan to address California’s use of the original excess of the Lower Basin allotment.
The Upper Basin States of Colorado, New Mexico, Utah and Wyoming still have to agree to their own Drought Contingency Plan to prevent a “Compact Call” under the Colorado Compact which would simply cut water to users across the Upper Basin States proportionally if they are unable to deliver the water, they are required to send through Lake Powell under the Colorado Compact.
Today, the river provides water to 40 million people and 5.5 million acres of farmland in Colorado, Wyoming, Utah, New Mexico, Nevada, Arizona and California, 29 Native American tribes and the Mexican states of Sonora and Baja California. Even without climate change, paleoclimate records show a history of tremendous droughts in the region, and now more than 40 million people (in the upper and lower basins) depend upon the Colorado River’s waters for their water supply.
1922 Colorado River Compact, negotiated by the seven basin states (Colorado, Nevada, Utah, New Mexico, Wyoming, Arizona, California, ) divided the Colorado River basin into upper and lower portions, allotted the Colorado’s water on the basis of territory rather than prior appropriation. Before this agreement was negotiated allocation of water rights (ownership) was based on historic use, first to use the water owned it in perpetuity. In a land where water was wealth and all water was diverted from its natural location, this was how it was done. The allocation of water rights based on territory allowed development to proceed in the lower basin (essentially California) while safeguarding supplies for the upper basin. Then, as now, California's growth and demand for water was viewed with concern by her neighbors.
The problem now is that the allocations promised under the Colorado Compact was based on an expectation that the river's average flow was 16.4 million acre feet per year and ignored the needs of nature and the tribes. Subsequent studies: however, have concluded that the long-term average water flow of the Colorado is less. In addition, according to the University of Arizona, records going back to paleolithic times (more than 10,000 years ago) indicates periods of mega-droughts in the distant past.
- Lake Powell’s January 1, 2022, water elevation will be 3,535 feet - about 165 feet below full. Based on this projection, Lake Powell will release 7.48 million acre-feet in water year 2022.
- Lake Meade will operate in its Level 1 Shortage Condition for the first time ever. The required water reductions negotiated under the series of negotiated interim guidelines for Lower Basin Shortages and Coordinated Operations of Lake Powell and Lake Mead:
- Arizona must reduce water use by 512,000 acre-feet, which is approximately 18% of the state’s annual apportionment.
- Nevada must reduce water use by 21,000 acre-feet, which is 7% of the state’s annual apportionment.
- Mexico will receive 80,000 acre-feet less, which is approximately 5% of the country’s annual allotment.
- California as the most senior water right holder in the lower basin does not have a reduction under Level 1 shortage conditions.
More than twenty years of drought, drying out of the West due to changing climate, and growing populations throughout the basin are creating a water crisis. Under the terms of the Colorado Compact the Upper Basin States must deliver 7,500,000-acre feet of water each year for the Lower Basin States and 1,500,000-acre feet for Mexico, an allotment for the tribes and an allotment to nature. The Lower Basin states of Arizona, California and Nevada were first to address their growing problem by creating a Drought Contingency Plan to address California’s use of the original excess of the Lower Basin allotment.
The Upper Basin States of Colorado, New Mexico, Utah and Wyoming still have to agree to their own Drought Contingency Plan to prevent a “Compact Call” under the Colorado Compact which would simply cut water to users across the Upper Basin States proportionally if they are unable to deliver the water, they are required to send through Lake Powell under the Colorado Compact.
Today, the river provides water to 40 million people and 5.5 million acres of farmland in Colorado, Wyoming, Utah, New Mexico, Nevada, Arizona and California, 29 Native American tribes and the Mexican states of Sonora and Baja California. Even without climate change, paleoclimate records show a history of tremendous droughts in the region, and now more than 40 million people (in the upper and lower basins) depend upon the Colorado River’s waters for their water supply.
1922 Colorado River Compact, negotiated by the seven basin states (Colorado, Nevada, Utah, New Mexico, Wyoming, Arizona, California, ) divided the Colorado River basin into upper and lower portions, allotted the Colorado’s water on the basis of territory rather than prior appropriation. Before this agreement was negotiated allocation of water rights (ownership) was based on historic use, first to use the water owned it in perpetuity. In a land where water was wealth and all water was diverted from its natural location, this was how it was done. The allocation of water rights based on territory allowed development to proceed in the lower basin (essentially California) while safeguarding supplies for the upper basin. Then, as now, California's growth and demand for water was viewed with concern by her neighbors.
The problem now is that the allocations promised under the Colorado Compact was based on an expectation that the river's average flow was 16.4 million acre feet per year and ignored the needs of nature and the tribes. Subsequent studies: however, have concluded that the long-term average water flow of the Colorado is less. In addition, according to the University of Arizona, records going back to paleolithic times (more than 10,000 years ago) indicates periods of mega-droughts in the distant past.
Now with more than twenty dry years, the reservoirs have dwindled to their lowest levels recorded.
Allotted shares of water in the basin to both the United States and Mexico exceeds the average long-term (1906 through 2018) historical natural flow of under 16.0 million acre-feet. To date, the imbalance has been managed, and demands largely met by slowly using up the considerable amount of reservoir storage capacity in the Colorado River system that once held approximately 60 million acre-feet (nearly 4 years of average natural flow of the river). It was assumed that drought years would be followed by wet year to refill the reservoirs. The basin is in its 22nd year of drought.
No comments:
Post a Comment