A new data set on water in Lake Powell and from Glen Canyon Dam, was published by the USGS this week. The purpose is so that "further interpretation may be made concerning mixing processes in Lake Powell, the movement and fate of advective inflow currents, effects of climate and hydrological variations, and the effects of the operation and structure of Glen Canyon Dam on the quality of water in Lake Powell and from Glen Canyon Dam releases."
Ref: Physical and Chemical Data for Water in Lake Powell and from Glen Canyon Dam Releases, Utah-Arizona, 1964-2008
Vernieu, William S., 2009, USGS Data Series 471