U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 9415021 PUBLICATION DATE: 09/28/2016 Name: BLACKSLOUGH LANDING, SAN JOAQUIN RIVER CA NOAA Chart: 18661 Latitude: 37° 59.7' N ( 37.99469) USGS Quad: HOLT Longitude: 121° 25.1' W (-121.41904) To reach the tidal bench marks from the junction of State Highway 4 and Interstate 5 in Crockett, proceed west on Highway 4 for 14 km (9 mi), then turn right and proceed north on Holt Road until the road dead ends at a T junction with Neugebauer Road. The bench marks are to the south of and along Neugebauer Road. The tide gage and staff were located on the peat loading dock north of a garage and mobile house. To reach the tide station proceed west from Stockton along Highway 4 from the junction of Highway 4 and Interstate 5, proceed 8.85km (5.5 mi) then turn right and proceed north on S. Island dr., proceed 4.8km (3.0 mi), turn right and proceed north on S. Holt rd., continue until the road dead ends at a T junction with Windmill Cove rd. Turn right on Windmill Cove rd. and proceed 0.18 km (0.11 mi). The tide station is 170 ft NE of gate located on the north side of Windmill Cove rd. T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 9415021 PUBLICATION DATE: 09/28/2016 Name: BLACKSLOUGH LANDING, SAN JOAQUIN RIVER CA NOAA Chart: 18661 Latitude: 37° 59.7' N ( 37.99469) USGS Quad: HOLT Longitude: 121° 25.1' W (-121.41904) T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 3 1933 DESIGNATION: POLE=TIDAL 3 MONUMENTATION: Tidal Station disk VM#: 8504 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: HS0359 SETTING CLASSIFICATION: Concrete base OPUS PID: LATITUDE: 37° 59.6' N ( 37.99403) LONGITUDE: 121° 25.3' W (-121.42250) The bench mark is located 160 m (525 ft) ESE from the intersection of N. Holt Rd. and Windmill Cove Rd., 47.55 m (156 ft) south of the centerline of Windmill Cove Rd. and 23.59 m (77.4 ft) SE of the center of the NW concrete anchor block. The bench mark is cemented into the upper surface of the NE corner of concrete base of the latticed steel transmission tower. BENCH MARK STAMPING: 5021 B 1977 DESIGNATION: 941 5021 B TIDAL MONUMENTATION: Tidal Station disk VM#: 8502 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 37° 59.6' N ( 37.99380) LONGITUDE: 121° 25.2' W (-121.41937) The bench mark is located 160 m (525 ft) east from the intersection of N. Holt Rd. and Windmill Cove Rd., 86 m (260 ft) south of the centerline of Windmill Cove Rd., 0.6 m (2 ft) west of a telephone pole, and 0.1 m (0.2 ft) above grade. The bench mark is on a rod driven 11 m (35 ft), and encased in a PVC pipe.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 9415021 PUBLICATION DATE: 09/28/2016 Name: BLACKSLOUGH LANDING, SAN JOAQUIN RIVER CA NOAA Chart: 18661 Latitude: 37° 59.7' N ( 37.99469) USGS Quad: HOLT Longitude: 121° 25.1' W (-121.41904) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5021 E 2014 DESIGNATION: 941 5021 E MONUMENTATION: Tidal Station disk VM#: 21999 AGENCY: US Army Corps of Engineers (USACE) IDB PID#: SETTING CLASSIFICATION: Concrete Base OPUS PID: LATITUDE: 37° 59.7' N ( 37.99428) LONGITUDE: 121° 25.4' W (-121.42261) The bench mark is located 160 m (525 ft) ESE from the intersection of N. Holt Rd. and Windmill Cove Rd., 24.72 m (88.1 ft ) south of the centerline of Windmill Cove Rd. and 23.90 m (78.4 ft) NW of the center of the concrete base of the latticed steel transmission tower. The bench mark is cemented into the upper surface of the SE corner of NW concrete anchor block. BENCH MARK STAMPING: 5021 D 2014 DESIGNATION: 941 5021 D MONUMENTATION: Tidal Station disk VM#: 22000 AGENCY: US Army Corps of Engineers (USACE) IDB PID#: SETTING CLASSIFICATION: Concrete base OPUS PID: LATITUDE: 37° 59.6' N ( 37.99414) LONGITUDE: 121° 25.3' W (-121.42228) The bench mark is located 160 m (525 ft) ESE from the intersection of N. Holt Rd. and Windmill Cove Rd., 34.05 m (111.7 ft) south of the centerline of Windmill Cove Rd., and 24.23 m (79.5 ft) NE of the center of the concrete base of the latticed steel transmission tower. The bench mark is cemented into the upper surface of the SW corner of the NE concrete anchor block.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 9415021 PUBLICATION DATE: 09/28/2016 Name: BLACKSLOUGH LANDING, SAN JOAQUIN RIVER CA NOAA Chart: 18661 Latitude: 37° 59.7' N ( 37.99469) USGS Quad: HOLT Longitude: 121° 25.1' W (-121.41904) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5021 F 2014 DESIGNATION: 941 5021 F MONUMENTATION: Tidal Station disk VM#: 22001 AGENCY: US Army Corps of Engineers (USACE) IDB PID#: SETTING CLASSIFICATION: Concrete base OPUS PID: LATITUDE: 37° 59.6' N ( 37.99365) LONGITUDE: 121° 25.4' W (-121.42268) The bench mark is located 160 m (525 ft) ESE from the intersection of N. Holt Rd. and Windmill Cove Rd., 70.53 m (231.4 ft) south of the centerline of Windmill Cove Rd., and 25.13 m (82.44 ft) SE of the center of the concrete base of the latticed steel transmission tower. The bench mark is cemented into the upper surface of the SW corner of the SE concrete anchor block.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 9415021 PUBLICATION DATE: 09/28/2016 Name: BLACKSLOUGH LANDING, SAN JOAQUIN RIVER CA NOAA Chart: 18661 Latitude: 37° 59.7' N ( 37.99469) USGS Quad: HOLT Longitude: 121° 25.1' W (-121.41904) T I D A L D A T U M S Tidal datums at BLACKSLOUGH LANDING, SAN JOAQUIN RIVER based on: LENGTH OF SERIES: 2 MONTHS TIME PERIOD: January 2015 - February 2015 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9415144 PORT CHICAGO, SUISUN BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 1.109 MEAN HIGH WATER MHW = 0.971 MEAN SEA LEVEL MSL = 0.561 MEAN TIDE LEVEL MTL = 0.555 MEAN LOW WATER MLW = 0.138 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 3 1933 -0.225 -1.196 5021 B 1977 2.191 1.220 5021 E 2014 -0.796 -1.767 5021 D 2014 -0.976 -1.947 5021 F 2014 -0.922 -1.893
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 9415021 PUBLICATION DATE: 09/28/2016 Name: BLACKSLOUGH LANDING, SAN JOAQUIN RIVER CA NOAA Chart: 18661 Latitude: 37° 59.7' N ( 37.99469) USGS Quad: HOLT Longitude: 121° 25.1' W (-121.41904) 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.