At the 2015 AFS WA-BC Meeting, Environmental Scientist Todd Hatfield presented on A Comparison of Desktop Hydrologic Methods for Determining Environmental Flows. Written and researched in collaboration with Environmental Flow Specialist Andrew Paul from Alberta’s Dept. of Environment and Sustainable Resource Development, this paper reviewed different desktop methods and their performance on a range of streams in British Columbia. All methods clearly articulated the trade-off between water use and ecosystem health; however, the desktop methods proved inconsistent in their assessments of various ecosystem health performance measures outside of fish habitat. See abstract below to learn more bout desktop hydrologic methods and how they should be applied to make better water allocation decisions.
Other highlights of the AFS conference included discussions on the latest tagging technologies demonstrating great strides in our ability to study the migration patterns of fish. As a leader in the renewable energy sector, Ecofish looks forward to utilizing these new technologies to further advance our research.
Abstract: Determining environmental flows can be a daunting task because fluvial systems are physically and biologically complex, and there can be difficult trade-offs between instream and out-of-stream water uses. Desktop methods are office-based exercises that use readily available hydrologic information to assess a proposed diversion of stream flows. This paper reviews six well-known desktop hydrologic methods. Seventeen performance measures (PMs), for ecosystem health (hydrology, habitat, geomorphology, connectivity, and water quality) and out-of-stream water use, are used to compare and contrast the predicted outcome of the desktop methods to three mid-size rivers with different hydrologic regimes. Results of the PM calculations demonstrate that absolute and relative performance of the six desktop methods is not consistent across the three streams. As a group, the desktop methods clearly underscored the trade-off between water use and ecosystem health; however, the methods had widely divergent performance for water use PMs and variable performance on the different ecosystem health PMs. All desktop methods performed well on the fish habitat PMs, but performance on the other ecosystem health PMs was variable and not consistent among methods. The results emphasize the need for clearly articulated objectives as an integral component of any desktop method and the benefit of transparent trade-off considerations during any water allocation decision.