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Scholars Request National Academy of Sciences Review of Colorado River

On October 13, 2015, a coalition of 23 scholars sent a letter to Secretary of the Interior Sally Jewell requesting that the National Academy of Sciences conduct an independent “science-based” review of the Colorado River Water Supply and Demand Study, the Next Steps Program and the Moving Forward Phase 1 Report.  The letter identifies seven areas for investigation.

Climate Change-Induced Streamflow Reduction Forecasts.  The Basin Study considered reductions in average future runoff of 9% by 2060.  Citing research identifying climate-change induced reductions between 6% and 45% by 2050 and 21st Century Colorado River streamflows 19% lower than in the 20th Century, “uncertainty about the average decline for future runoff dictates that water managers should incorporate a suite of supply scenarios in their strategic planning.”

Groundwater Impacts.  Declining surface water supplies and increased water demands may stress groundwater resources, either in terms of recharge or increased utilization.  The letter states that “these relationships were not adequately addressed in the Basin Study.”  The scholars believe that “more comprehensive evaluations of the interactions between groundwater and surface water is clearly needed.”

Flood Management.  While most focus on drought, major floods will continue to occur in the Colorado River system.  Given the recent discovery of 2,000 year flood history revealing higher magnitudes and frequencies than previously known, “it remains unclear to what extent the water conveyance infrastructure can be safely managed to route the types of floods that Nature has historically visited upon this watershed.”

Water Demand Forecasts.  The scholars argue that the Basin Study overstates the magnitude of potential water shortages.  Population projections are outdated.  In addition, there was “inattention to growing water conservation trends underway throughout the basin.”  They advocate needs assessments “that offer demand scenarios that fit within available supply limits.”

Ecology.  The scholars acknowledge the attention given to ecological water flows through the Moving Forward Effort; “what remain unclear are the long-term prognosis for habitat recovery and the challenges and trade-offs needed to achieve it across the entire ranges of critical habitat within the Colorado River watershed.”

Water Quality.  While the Basin Study examined salinity levels in the Colorado River water, the scholars raised concerns about the potential for more intense climate-change-induced reductions in streamflow.  They believe that many other constituents may become problematic (pesticides, selenium, mercury, arsenic, hexavalent chromium, perchlorate rocket fuel and endocrine disruptors from pharmaceuticals).  They also cite concerns about hydraulic fracturing practices and “thousands of defunct mines and drilling installations within the basin that are still awaiting remediation.”

Vulnerability.  To fulfill its obligations under the 2009 Water Secure Act, the scholars urge the Department of the Interior first conduct a comprehensive climate-change vulnerability assessment of the Colorado River Basin.  They are unsure how the Moving Forward Efforts will undertake the assessment including “the society and ecosystems that depend upon it.”

The scholars argue that, when it approved the 2009 Act, Congress recognized the need to assist stakeholders in developing “a management plan that will adapt to the changing hydrology of the Colorado River.”  They see the need to include all issues identified above.

Role of National Academy of Sciences Review.  “It is reasonable to request that DOI seek an impartial review of the Basin Study process to ensure that the program is indeed on track.  Such independence and expertise can more objectively confront the difficult issues that might otherwise continue to escape through the cracks amidst the challenges of maintaining this stakeholder-driven process.”

The scholars foresee “significant challenges” impeding integration of scientific findings into Colorado River management. “The proposed review should examine the institutional barriers and capacity limitations constraining the use of science’s best articulation of the complex variables at play…to realize more resiliency, robustness and flexibility” in water resource management.  The review should therefore consult practitioners at federal, state and tribal levels …to identify pathways that will ensure valuable scientific research better informs decision-making.”


Given the complexity and importance of the challenges confronting the Colorado River, solutions based on sound science will have a greater prospect for success than solutions based on flawed science.  As such, the request for a National Academy of Science review of the Colorado River Basin Study efforts could prove helpful. However, the most productive exercise would be an assessment based on an acknowledgment of what is known and what is unknown, with well-defined identifications of the magnitudes and sources of uncertainty.  This perspective could inform the assessments of alternative courses of actions, including risk-assessments for actions.

While science, in and of itself, will not solely drive outcomes, developing a commonly-accepted framework for identifying challenges and assessing alternatives can assist the Colorado River Basin stakeholder process find common grounds as they address the economic, environmental and social issues confronting the Colorado River Basin.


Written by Rodney T. Smith, Ph.D.