New Report on Impact to San Miguel River From Proposed Reservoirs
By: Evan Stafford
Colorado - American Whitewater has released a new study on whitewater recreation in the San Miguel River Basin. As a product of our dedicated work defining recreational flows and representing whitewater recreation interests for the Colorado Water Plan, the Colorado Water Conservation Board (CWCB) requested that Montrose County consult with American Whitewater on recreational needs and future impacts for the San Miguel River. Montrose County acquired conditional water rights to the San Miguel River in southwest Colorado in hopes of building multiple new reservoirs on BLM land. American Whitewater worked with Montrose County’s agents to assess the impact its conditional storage proposals would have on existing recreational opportunities.
Using flow ranges American Whitewater defined though a study earlier in 2016 and historic hydrologic data from the United States Geological Survey (USGS), AW defined the number of boatable days (days throughout the year when flows are above minimum and below maximum acceptable levels) in four different year types: dry, dry average, wet average, and wet for the San Miguel River. This Boatable Days analysis allows for assessing the affect that future reductions in flow, attributed to new projects, will have on boatable days available for whitewater users. Montrose county supplied simulated daily depletions (cfs) for historic water years associated with three project alternatives and American Whitewater used these simulated depletions to recalculate the number of days when boatable flows would have been available with these reduced flows.
American Whitewater found no reduction in boatable days due to the simulated depletions in historic flows for any of the alternatives provided for the San Miguel River. This was not surprising considering the three alternatives only resulted in average annual changes in flow of ~ 1% and average daily depletions of under 4 cfs. This study sets a new precedent for American Whitewater’s involvement in assessing the future impacts new water projects will have on recreation opportunities in Colorado and possibly across the country. Developing the Boatable Days metric provides the best quantification of river-related recreation opportunities and enables decision-makers to assess and address the impacts to whitewater boating attributes in future water rights development and water demand scenarios. We are proud to have put this assessment to use for the first time in a state sponsored consulting role and are excited to use this method in the analysis of impacts to recreation from proposed future water projects.
If you are interested in reviewing our study you can read it or download a copy of it HERE.