Estimation of Reservoir Storage Capacity and Geomorphic Change Detection Analysis From a Multibeam Bathymetric Survey of Randy Poynter Lake, Rockdale County, Georgia
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- Document: Report (7.67 MB pdf)
- Data Releases:
- USGS Data Release - Watershed characteristics and streamwater constituent load data, models, and estimates for 15 watersheds in Gwinnett County, Georgia, 2000–2021
- USGS Data Release - Bathymetric and supporting data for estimation of reservoir storage capacity and geomorphic change detection analysis from a multibeam bathymetric survey of Randy Poynter Lake, Rockdale County, Georgia
- Download citation as: RIS | Dublin Core
Abstract
Rockdale County Department of Water Resources has a directive to update estimates of the reservoir storage capacity of Randy Poynter Lake, located in northern Georgia, and to assess recent sedimentation and associated storage capacity loss. In 2022, the U.S. Geological Survey completed a multibeam bathymetric survey of Randy Poynter Lake to update storage capacity estimates and to quantify storage capacity change since the first multibeam bathymetric survey in 2012 in consideration of estimated errors inherent to bathymetric surveys. Data from the 2022 survey were used to generate contours of the reservoir as well as compute storage capacity at regular increments of water-surface elevation. Storage capacity comparisons between 2012 and 2022 at Randy Poynter Lake show minimal changes that are within the estimated uncertainties, with consistent or slightly increased storage capacities observed at most water-surface elevations and reductions observed at the remaining few elevations. Comparison of the multibeam bathymetric data collected in 2012 with data collected in 2022 further allowed for a formal geomorphic change detection analysis to map, quantify, and infer causation of morphological change over time with respect to a level of detectable change. The volume change in Randy Poynter Lake for the decade between 2012 and 2022 was slightly net-depositional and within the estimated uncertainty. The spatial distribution of sediment deposition was primarily concentrated in the northern portion of the lake, where the principal tributary flows into Randy Poynter Lake. The results of the geomorphic change analysis were used to further understand the future implications to storage capacity change. Despite the challenges of confirming systematic biases because of uncertainties exceeding the observed changes, insights from the study help predict long-term reservoir sediment accumulation, indicating a reservoir half-life extending about 650 years from 2022 on the basis of the current sediment yield estimates.
Suggested Citation
Whaling, A.R., and Bolton, W.J., Estimation of reservoir storage capacity and geomorphic change detection analysis from a multibeam bathymetric survey of Randy Poynter Lake, Rockdale County, Georgia: U.S. Geological Survey Scientific Investigations Map 3523, 2 sheets, https://doi.org/10.3133/sim3523.
ISSN: 2329-132X (online)
Study Area
Table of Contents
- Abstract
- Introduction
- Methods
- Geomorphic Change Detection
- Uncertainty
- Storage Capacity Change
- Potential Implications to Reservoir Life
- References Cited
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Estimation of reservoir storage capacity and geomorphic change detection analysis from a multibeam bathymetric survey of Randy Poynter Lake, Rockdale County, Georgia |
| Series title | Scientific Investigations Map |
| Series number | 3523 |
| DOI | 10.3133/sim3523 |
| Year Published | 2024 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Contributing office(s) | Lower Mississippi-Gulf Water Science Center |
| Description | 2 Sheets: 47.00 x 32.23 inches; 2 Data Releases |
| Country | United States |
| State | Georgia |
| County | Rockdale County |
| Other Geospatial | Randy Poynter Lake |
| Online Only (Y/N) | Y |
| Google Analytic Metrics | Metrics page |