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In June 2021, a high-resolution bathymetric survey of the Bethany Reservoir was conducted to document current lakebed elevations for comparison with as-built elevations, and to gather detailed information of the submerged water control structures within the basin. The primary tasks of this effort were to:
1. Assess sedimentation in the reservoir since dredging occurred in 2018 at the lower-level outlet structure.
2. Inspect Christensen Bridge, Check 1, and the South Bay Pumping Plant (SBPP).
3. Update stage vs. storage charts if significant change has occurred in the reservoir since initial filling.
Interpolated bathymetry of Bethany Reservoir from 05/20/2022. Raster resolution is 1 foot. This is an official DWR Image Service, which meets all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standard version 3.5, dated April 12, 2023. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. This Image Service was published on 05/10/2023, by the DWR Division of Engineering, who may be contacted at gis@water.ca.gov. Comments, problems, improvements, updates, or suggestions should be forwarded to the official DWR point of contact as available and appropriate.
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In June 2021, a high-resolution bathymetric survey of the Bethany Reservoir was conducted to document current lakebed elevations for comparison with as-built elevations, and to gather detailed information of the submerged water control structures within the basin. The primary tasks of this effort were to:
1. Assess sedimentation in the reservoir since dredging occurred in 2018 at the lower-level outlet structure.
2. Inspect Christensen Bridge, Check 1, and the South Bay Pumping Plant (SBPP).
3. Update stage vs. storage charts if significant change has occurred in the reservoir since initial filling.
Interpolated bathymetry of Bethany Reservoir from 05/20/2022. Raster resolution is 1 foot. This is an official DWR Image Service, which meets all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standard version 3.5, dated April 12, 2023. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. This Image Service was published on 05/10/2023, by the DWR Division of Engineering, who may be contacted at gis@water.ca.gov. Comments, problems, improvements, updates, or suggestions should be forwarded to the official DWR point of contact as available and appropriate.
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| accessInformation:
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California Department of Water Resources (DWR), North Central Region Office (NCRO) |
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thumbnail/thumbnail.JPEG |
| typeKeywords:
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["Data","Service","Image Service","ArcGIS Server"] |
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1.5E8 |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>Bethany Reservoir was completed in 1967 as one of the initial components of the State Water Project. The South Bay Aqueduct begins at Bethany Reservoir, located on the California Aqueduct, 1.5 miles downstream from Banks Pumping Plant, which is 12 miles northwest of Tracy, California. The reservoir serves as the forebay for the SBPP and the afterbay of Banks Pumping Plant. In this reach of the California Aqueduct, Bethany Reservoir serves as a conveyance facility and provides public outdoor recreational opportunities (California Department of Water Resources 1999). Construction of the forebay dam began in 1959 and was completed in 1961, with the adjacent dams and a connecting channel constructed between 1965 and 1967 (California Department of Water Resources 1999). In 2007, an enlargement of the SBPP was constructed, which involved excavation and sediment removal in the pumping plant forebay (California Department of Water Resources 2007). In 2017, a dredging operation was undertaken to remove sediment from the low-level intake structure for the outlet works at the Bethany Forebay Dam at the northwest end of the reservoir.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>All data are referenced to the standards specified by the California Department of Water Resources (DWR) Division of Engineering (DOE), listed below. These standards were also used for the 2015 light detection and ranging (LiDAR) survey of the reservoir from which construction plans were derived in 2021. Horizontal datum: 1983 California Coordinate System National Geodetic Survey Continuous Operating Reference Stations Epoch 2010.00 (2011.00 realization), Zone 3, U.S. Survey Feet. Vertical datum: North American Vertical Datum of 1988 (NAVD88) on geoid 12a, U.S. Survey Feet.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>The equipment listed below was used for the bathymetric survey of the Bethany Reservoir.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>Multibeam Bathymetry Echosounder System:</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Oquawka 2072 vessel.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Reson T20-P dual-head multibeam echosounder.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Applanix POS-MV OceanMaster Inertial Measurement Unit with Zephyr model 2 antennas.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Odom Hydrographic Digibar Pro sound velocimeter.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Valeport Mini SVS sound velocimeter.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>Singlebeam Bathymetry Echosounder System:</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Kingfisher 1825 Falcon XL Vessel.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Odom Hydrographic CV100 echosounder.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Odom SMSW200-4a 200 kilohertz transducer.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Applanix POS-MV WaveMaster II Inertial Measurement Unit with Zephyr model 2 antennas.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Valeport MiniSVS sound velocimeter.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>Terrestrial Surveys:</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• Real-time kinematic (RTK) global positioning system (GPS) base station (all days): Trimble R8-3 at 2 meters.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>• RTK-GPS rover (all days): Trimble R8-3 at 2 meters.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>Multibeam bathymetry data were collected on the 20-foot aluminum hull survey vessel Oquawka using a dual-head multibeam bathymetry echosounder system. Hypack hydrographic survey software was used for acquisition and postprocessing of the soundings. Georeferencing and motion compensation data from the POS-MV system were post-processed in Applanix POSPac software by DOE Geomatics staff. CARIS HIPS & SIPS software was used for final cleaning of the data, and ESRI ArcGIS software was used for spatial analyses and the creation of final map products. The final density level of the data points is a 1-foot grid. Supplemental singlebeam bathymetry data were collected on the 18-foot aluminum hull survey vessel Kingfisher. Hypack hydrographic survey software was used for acquisition and post-processing of the soundings. Georeferencing and motion compensation data from the POS-MV system were post-processed in Applanix POSPac software by DOE Geomatics staff. ESRI ArcGIS software was used for spatial analyses and the creation of final map products.</SPAN></SPAN></P><P STYLE="margin:0 0 7 0;"><SPAN>An interpolated surface was created using multibeam and singlebeam bathymetry collected by DWR combined with 2015 LiDAR data collected by Towill Inc. on behalf of DWR. Where multibeam and validated LiDAR data overlapped, LiDAR was considered the primary data source because multibeam in these areas was from the extreme outer beams of the sounder, which are inherently less accurate than beams closer to nadir. Where multibeam and singlebeam data overlapped, multibeam was considered primary because of much higher data density. A triangulated mesh interpolation model was built to fill gaps between multibeam, singlebeam, and LiDAR data to at least the spillway elevation (248 feet). The resulting model was evaluated for apparent inconsistencies, and then mosaicked with the multibeam and LiDAR data to produce the final interpolated surface. There were gaps of up to 160 feet between available soundings and LiDAR data around the shore, but these extremes were only in shoalest parts of the reservoir (mostly the gullies leading into the main reservoir from the southwest) where bathymetric vessels were unable to access. The implicit assumption in the interpolated model is that there is a gradual linear slope between LiDAR along the shoreline and the nearest bathymetric soundings. Although this assumption could be more accurately characterized by use of extreme shallow water bathymetry platforms and manual surveying in waders, it was both beyond the scope of this project and deemed unnecessary for the final product, considering the trivial volume these areas contribute to the total reservoir capacity.</SPAN></P></DIV></DIV></DIV> |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 7 0;"><SPAN><SPAN>Not to be used for navigation.</SPAN></SPAN></P><P><SPAN /></P></DIV></DIV></DIV> |
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| title:
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Bathy_NCRO_20220520_BethanyReservoir_Interpolated |
| type:
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Image Service |
| url:
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https://parcgis.water.ca.gov/arcgisimgpublicmngr/services/Bathymetry/Bathy_NCRO_20220520_BethanyReservoir_Interpolated/ImageServer |
| tags:
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["bathymetry","bethany","reservoir","elevation","san joaquin river","delta","i06","ncro","doe"] |
| culture:
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en-US |
| name:
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Bathy_NCRO_20220520_BethanyReservoir_Interpolated |
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| MaxScale:
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5000.0 |
| spatialReference:
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NAD_1983_2011_StatePlane_California_III_FIPS_0403_Ft_US |