{ "culture": "en-US", "name": "", "guid": "", "catalogPath": "", "snippet": "Provide bathymetric data for the deep draft navigation and adjoining areas of San Pablo Bay, Carquinez Straits, Suisun Bay, Sacramento DWSC, and Stockton DWSC.\n\nThe associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standard version 3.4, dated September 14, 2022. DWR makes no warranties or guarantees \u2014 either expressed or implied \u2014 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. Comments, problems, improvements, updates, or suggestions should be forwarded to gis@water.ca.gov.", "description": "

Third Order, Class II Hydrographic Survey was conducted per USACE, EM 110-2-1003, January 2002. NOTE: The hydrographic survey utilized First Order, Class I standards and survey equipment, but the survey is classified as Third Order, Class II because tide gauges and survey line spacing are further apart than allowable for Class 1 surveys.<\/SPAN><\/P>

A single-beam INNERSPACE Model 455 survey-grade depthsounder was used to collect water depth data along predetermined transects of the navigation channels. Echo sounder had a frequency of 200kHz, with a 3.5 degree cone measured at 6-db point. Echosounding calibration check was conducted a minimum of 2 times per day, including immediately before and after survey operations. Top of return trace used as point of interpretation of sounding. Bar checks taken at a minimum of five foot intervals from the surface to 35' depths. Before and after bar checks taken at identical locations within a work area. The mean of the before and after bar checks used to correct all observed data recorded within a given work area. Data rejected if agreement between before and after bar checks greater than 0.3 feet. The survey vessel collected 20 soundings per second while moving at 5-knots (8.5 feet per second), for an average density of more than 2 soundings per foot of trackline. Soundings were thinned and input into AutoCAD .dwg file for plotting.<\/SPAN><\/P>

Transects in the large, primary channels, such as the Sacramento River, False River, and San Joaquin River, were spaced every 400 feet. Transects were acquired every 1000 feet in Sherman Lake and Frank's Tract. Tributary channels wider than 300 feet, were surveyed every 400 feet a minimum distance of 1600 feet upstream from confluence with primary channels. In the bay regions, such as San Pablo Bay and Suisun Bay, survey lines were spaced every 400 feet except in the Carquinez Straits and San Pablo Straits where transects were every 1000 feet.<\/SPAN><\/P>

Soundings were corrected for tides measured using barometric-compensated, pressure-sensing tide gauges. Up to 8 tide gauges were installed simultaneously at nominal 2-mile intervals along the ship channels, and soundings were always collected between upstream and downstream tide gauges. The tide gauges are called MACROTIDE and are manufactured by Coastal Leasing of Cambridge, Massachussetts. The tide gauges were programmed to sample at 0.5-second intervals for 2-minutes at 6-minute intervals. The tide gauges include 2 pressure sensors, including one for measuring atmospheric pressure and the other for measuring underwater pressure. The pressure sensors in the tide gauge are ICS strain gauges that measure psia to 30m with 0.1% (0.1-foot) accuracy.<\/SPAN><\/P>

Software was used to process the pressure data and compute water level data at 1-minute intervals. Gauges were calibrated at factory prior to deployment. Water level data was calibrated by periodically using a weighted tape to manually measure the elevation of the water surface using a nearby NAVD-88 benchmark as vertical reference. Manual calibrations matched the recorded tide data within +/-0.1 feet. Multiple tide gauges were established at nominal 2-mile intervals so that tide data would be available no more than 5000 feet from the area being surveyed. Tide gauge readings were made and documented at the start of each survey line.<\/SPAN><\/P>

New geodetic control was established landside, so that tide gauge elevations could be determined relative to NAVD88 benchmarks along the entire length of the survey.<\/SPAN><\/P>

Water Levels were used in conjunction with water depth data, vessel test course calibration and squat/settlement curves, to determine topographic elevations of the river bottom and seabed. All hydrographic procedures conformed with \"Hydrographic Manual\", USACE manual update, January 2002 (EM1110-2-1003).<\/SPAN><\/P>

All hydrographic data \"field finished\" allowing collection, processing and plotting of cross-sections in the field for real-time data review.<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>", "summary": "Provide bathymetric data for the deep draft navigation and adjoining areas of San Pablo Bay, Carquinez Straits, Suisun Bay, Sacramento DWSC, and Stockton DWSC.\n\nThe associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standard version 3.4, dated September 14, 2022. DWR makes no warranties or guarantees \u2014 either expressed or implied \u2014 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. Comments, problems, improvements, updates, or suggestions should be forwarded to gis@water.ca.gov.", "title": "i06_Bathy_USACE_20050623_SanPabloBay_to_Pittsburg", "tags": [ "Bathymetry", "Sacramento Deep Water Ship Channel", "Hydrographic Survey", "Stockton Deep Water Ship Channel", "John F. Baldwin Ship Channel", "JFB Ship Channel", "Manmade Channel", "Elevation", "ISO 006", "Sacramento", "San Joaquin Delta", "Walnut Grove", "Ryde", "Slough", "July", "Single Beam", "USACE", "DWR GIS Atlas" ], "type": "", "typeKeywords": [], "thumbnail": "", "url": "", "minScale": 150000000, "maxScale": 5000, "spatialReference": "", "accessInformation": "Hydrographic survey was conducted by Sea Surveyor, Inc. (Geophysical Survey Permit PRC-8429 issued by California State Lands Commission, expiration October 2008); Survey control provided by Bestor Engineers, Inc. All work contracted by the US Army Corps of Engineers, San Francisco District. Funding was provided by Federal Appropriations and non-Federal matching funds provided by the Port of Stockton and Port of Sacramento.", "licenseInfo": "

The Government furnishes this data and the recipient accepts and uses it with the express understanding that the United States Government makes no warranties, expressed, or implied, concerning the accuracy, completeness, reliability, usability, or suitability for any particular purpose of the information and data furnished. The United States shall be under no liability whatsoever to any person or organization by reason of any use made thereof. <\/SPAN>Not for use as a navigation aid. The data reflects measurements taken at specific time periods and the Department of Water Resources makes no claim as to the current state of these waterways. Do not share or publish this data without including proper attribution.<\/SPAN><\/P>

The original source projection of the DWR GIS atlas dataset was California Teale Albers, NAD83. For copies of data in original projection, please contact DWR directly.<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>", "portalUrl": "" }