DOE protects critical fish habitat at the site along the Colorado River through a surface water initial remedial action system. Critical habitat areas are created along the edge of the Colorado River where backwater pools form as the river rises mostly during spring runoff. Suitable habitats are defined as low velocity backwater channels that are closed off on the upriver side, but are open downriver. The backwater pools serve as fish habitat and may expose endangered fish species to ammonia from the site through ground water discharge into the pools.
The surface water initial action introduces Colorado River water to backwater pools to reduce potentially elevated ammonia concentrations by flushing the areas with river water pumped from an upstream location. River water is introduced with minimal physical alteration to the habitat.
The initial action is implemented only for river flows between 10,000 cubic feet per second (cfs) and 15,000 cfs (as measured at the Cisco, Utah, gaging station) where critical habitat areas are most likely to emerge. At flows greater than 15,000 cfs, areas are completely submerged and at flows less than 10,000 cfs, critical habitat areas typically are dry.
For the 2009 runoff season, DOE monitored backwater channels for potential habitat areas. Suitable habitats are not likely to form unless there is a substantial increase or decrease in river flow. A suitable habitat was observed for only 2 days near one portion of the well field. Field screening was conducted when the habitat area was established. The ammonia concentration of the habitat area was below the acute and chronic criteria for the Colorado Pikeminnow; therefore, it was not necessary to divert any river water into this area. As of mid-August 2008, the Colorado River flows dropped to the point where habitat areas no longer existed. The river flow and areas where backwater pools are likely to be formed will be monitored until the end of September, when young-of-year pikeminnow are no longer present.
DOE monitors the river water flow each year and is prepared to implement the initial action if conditions warrant, as addressed in Work Plan for Implementation of the Initial Action at the Sandbar Area Adjacent to the Moab Project Site. The initial action was implemented for the first time in summer 2005. Implementation of the initial action for 2008 was incorporated as part of the biota monitoring and the results are discussed in the Final Report 2008 Biota Monitoring.
DOE monitors estimated Colorado River flow rates for the Cisco, Utah, gaging station (based on upstream flow rates and weather systems impacting the Colorado River basin) using the National Oceanic and Atmospheric Administration (NOAA) website. In addition, DOE monitors the NOAA Western Water Supply Forecast web page, which provides a long-term seasonal runoff volume forecast.