Improving tailwater ecosystem metabolism estimation—Metabolism and associated environmental data from a model comparison exercise for the Colorado River tailwater below Glen Canyon Dam—2008-2014

These data were compiled to model ecosystem metabolism in the Glen Canyon Dam tailwater (e.g., the Colorado River below Glen Canyon Dam). The primary objective of our study was to develop a new ecosystem metabolism model which we refer to as the variable flow two-station (VFTS) model. The VFTS modifies the classic two-station metabolism approach to account for unsteady flow, thus allowing for more accurate metabolism estimation in tailwater environments. In pursuit of this broader objective, we leveraged ongoing continuous water quality measurements being collected at two sites in the lower half of the Glen Canyon Dam tailwater (Colorado River; -8 mile to Lees Ferry) to assess our new model's performance under various input data constraints (e.g., travel time accuracy). We also assessed our new model's performance relative to both a highly complex two-station model and the community standard one-station modeling approach, the latter of which we believe is inappropriate for use in tailwater environments. These data include sub-daily environmental inputs required for our new model, which were collected in the lower half of the Glen Canyon Dam tailwater between March 2008 and April 2014 by the U.S. Geological Survey Grand Canyon Monitoring and Research Center (GCMRC). These data can be used to examine trends and drivers in Glen Canyon tailwater ecosystem metabolism and to explore the effects of input (travel time) accuracy and model choice on metabolism estimation in lotic habitats subject to subdaily flow variation.