Sea Surveyor, Inc
SINCE 1985



Precision marine surveys for the engineering community



SF Bay Tide Monitoring

Monitoring Sealevel in South SF Bay


Client: U.S. Army Corps of Engineers, San Francisco District

Completion Date: 2012

Contract Value: $285K

Tide Station2

NOS St. 941-4575
Coyote Creek/Alviso Slough

Sea Surveyor conducted a 1-year comprehensive evaluation of project datums (CEPD) in support of the South San Francisco Bay Salt Pond Restoration Project managed by the US Fish & Wildlife Service.  Sea Surveyor purchased and installed NOAA-compliant water level station at two (2) historic NOS tide stations, including Dumbarton Bridge East Fishing Pier (NOS Station 941-4509) and an electric transmission tower located at the confluence of Coyote Creek/Alviso Slough (NOS Station 941-4575).  Sea Surveyor installed Aquatrak acoustic tide gauges inside stilling wells and monitored water surface elevations at 6-minute intervals for continuous periods of 6-months at Dumbarton Bridge (Aug. 1 to Sept 7) and 1-year at Coyote Creek/Alviso Slough  (March 2011 to March 2012).  Based upon the tide measurements, sealevel elevations were computed using NOAA-compliant methods and standards.  Water level data was recorded on-site by SUTRON and STEVENS dataloggers, and cellular modems transmitted the data to Sea Surveyor’s SSItide website, where the real-time data was reviewed and underwent rigorous quality control.  Registered land surveyors installed new tidal benchmarks at both tide station locations and established their NAVD-88 elevations.



NOAA-Compliant Tide Station Submittals Include:


NOS St. 941-4509 Dumbarton Bridge East Fishing Pier

  1. Transmittal letter
  2. Data Checkoff List
  3. Tide Station Xpert Site Reports
  4. Chartlets and USGS Quad Map
  5. Permits and Property Owner Agreements
  6. Benchmark Descriptions & “To-Reach” Statements
  7. Sensor Elevation Drawing
  8. Sensor Elevation Diagram
  9. Calibration Certificates
  10. Bench Mark Sketch
  11. Photos of Benchmarks, Tide Station, DCP, & Well
  12. Levels and Field Notes of Precise Leveling
  13. Staff to Gauge Observations
  14. Datum Offset Computation Worksheet
  15. GPS Deliverables
  16. Water Level Data
  17. Tide Calculations