U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 4 Station ID: 9415447 PUBLICATION DATE: 02/26/2004 Name: SONOMA CREEK, WINGO CA NOAA Chart: 18654 Latitude: 38° 12.6' N ( 38.21000) USGS Quad: SONOMA Longitude: 122° 25.6' W (-122.42700) To reach the tidal bench marks from the intersection of State Routes 121 and 37, proceed north along Route 121 to Sonoma Rock Company property, then turn right and proceed east on the driveway and toward the railroad tracks, then turn left and proceed north along a dirt road to the railroad bridge over the creek. The bench marks were located at the Wingo Railroad Bridge and extend south along dirt road between railroad tracks and Sonoma Creek. The tide gage and staff were located on fender piling at NE corner of drawspan of railroad bridge over creek. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 5447 C 1979 DESIGNATION: 941 5447 C TIDAL MONUMENTATION: Tidal Station disk VM#: 8680 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 38° 12.6' N ( 38.21000) LONGITUDE: 122° 25.6' W (-122.42700) The primary bench mark is a disk located 161 m (528 ft) south along dirt road from SE end of railroad bridge over creek, 2 m (6 ft) east of eastern edge of road, and 0.30 m (1 ft) north of wooden post. The bench mark is set at grade level, crimped to the top of a galvanized steel deep rod driven 16.5 m (54 ft) to refusal, encased in PVC pipe.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 4 Station ID: 9415447 PUBLICATION DATE: 02/26/2004 Name: SONOMA CREEK, WINGO CA NOAA Chart: 18654 Latitude: 38° 12.6' N ( 38.21000) USGS Quad: SONOMA Longitude: 122° 25.6' W (-122.42700) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5447 A 1979 DESIGNATION: 941 5447 A TIDAL MONUMENTATION: Tidal Station disk VM#: 8678 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Pier of railroad bridge OPUS PID: LATITUDE: 38° 12.6' N ( 38.21000) LONGITUDE: 122° 25.6' W (-122.42700) The bench mark is a disk set on top of the SE pier of the railroad bridge over Sonoma Creek, 31 m (101 ft) north of south end of bridge, 2 m (6 ft) east of easternmost rail, 15 cm (0.5 ft) from edge of pier, and 3 cm (0.1 ft) south of south end of drawspan. BENCH MARK STAMPING: 5447 B 1979 DESIGNATION: 941 5447 B TIDAL MONUMENTATION: Tidal Station disk VM#: 8679 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 38° 12.6' N ( 38.21000) LONGITUDE: 122° 25.6' W (-122.42700) The bench mark is a disk located 80 m (264 ft) south along the road from the SE end of railroad bridge, 3 m (10 ft) SW of west side of road, and 0.76 m (2.5 ft) SW of witness post. The bench mark is crimped to the top of a galvanized steel deep rod, driven 14.9 m (49 ft) to refusal, encased in PVC pipe extending 15 cm (0.5 ft) above grade.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 4 Station ID: 9415447 PUBLICATION DATE: 02/26/2004 Name: SONOMA CREEK, WINGO CA NOAA Chart: 18654 Latitude: 38° 12.6' N ( 38.21000) USGS Quad: SONOMA Longitude: 122° 25.6' W (-122.42700) T I D A L D A T U M S Tidal datums at SONOMA CREEK, WINGO based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: October 1979 - October 1979 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9414290 SAN FRANCISCO, SAN FRANCISCO BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 1.786 MEAN HIGH WATER MHW = 1.613 MEAN SEA LEVEL MSL = 0.931 MEAN TIDE LEVEL MTL = 0.929 MEAN LOW WATER MLW = 0.245 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 5447 C 1979 0.687 -0.926 5447 A 1979 2.251 0.638 5447 B 1979 0.559 -1.054
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 4 Station ID: 9415447 PUBLICATION DATE: 02/26/2004 Name: SONOMA CREEK, WINGO CA NOAA Chart: 18654 Latitude: 38° 12.6' N ( 38.21000) USGS Quad: SONOMA Longitude: 122° 25.6' W (-122.42700) D E F I N I T I O N S Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal Datum Epoch. It pertains to local mean sea level and should not be confused with the fixed datums of North American Vertical Datum of 1988 (NAVD88). NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum constraint adjustment of Canadian/Mexican/United States leveling observations. Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as the single initial constraint. NAVD88 replaces NGVD29 as the national standard geodetic reference for heights. Bench mark elevations relative to NAVD88 are available from NGS through the World Wide Web at National Geodetic Survey. NGVD29 is a fixed datum adopted as a national standard geodetic reference for heights but is now considered superseded. NGVD29 is sometimes referred to as Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological Survey Topographic Quads. NGVD29 was originally derived from a general adjustment of the first-order leveling networks of the U.S. and Canada after holding mean sea level observed at 26 long term tide stations as fixed. Numerous local and wide-spread adjustments have been made since establishment in 1929. Bench mark elevations relative to NGVD29 are available from the National Geodetic Survey (NGS) data base via the World Wide Web at National Geodetic Survey. NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships to local MSL and other tidal datums may not be consistent from one location to another. The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique identifiers for bench marks in the tidal and geodetic databases, respectively. Each bench mark in either database has a single, unique VM# and/or PID# assigned. Where both VM# and PID# are indicated, both tidal and geodetic elevations are available for the bench mark listed. The NGS's Integrated Data Base (IDB PID) provides geodetic datum based on traditionally leveled and bluebooked ties to the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/. The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/. The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have NAVD88 elevations. The NAVD88 elevation relationship shown in the table is derived from an average of several bench mark elevations relative to tide station datum. As a result of this averaging, NAVD88 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from NAVD88 elevations listed for each bench mark in the NGS database.