Sedimentation rates for many reservoirs may be skewed by overstated estimates of design capacity and assumptions perpetuated through subsequent volumetric surveys; an error that may be unknowingly perpetuated in soil conservation strategy over time. Multi-frequency reservoir surveys offer the means by which we may improve existing reservoir data and validate historic sediment delivery estimates. To demonstrate application of this technology and value of its data derivatives, a multi-year, multi-frequency acoustic survey of Granger Lake, located in Williamson County, Texas was undertaken. Objectives of the study were to use hydro-acoustic survey techniques to verify assumptions of original reservoir capacity, examine the general accuracy of previously derived sedimentation rate, and document conservation implementation effectiveness. The intended benefit of these pre and post-watershed conservation implementation project surveys was to provide a temporal snapshot of sediment flux. Specifically, these data would be used as a tool to quantitatively estimate project success or non-success in annual sediment delivery reduction to the reservoir. Revised/corrected data indicates a mid-1990's acceleration of reservoir sedimentation which appears to be coincident with a rapidly expanding urban component within the San Gabriel Watershed.   Current conservation implementation is not plainly responsible for change in sediment delivery (2007-2010), and in fact conservation effects may be undetectable for the foreseeable future. Insights from this research highlight the importance of validating historic reservoir survey data and significance regarding use of sub-bottom profiling as a validation tool for quantifying historic and future conservation effects.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.