U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 PUBLICATION DATE: 06/06/1996 Station ID: 9414290 SUPERCEDED DATE: 04/21/2003 Name: THE PRESIDIO, SAN FRANCISCO CALIFORNIA NOAA Chart: 18649 Latitude: 37° 48.4' N USGS Quad: SAN FRANCISCO NORTH Longitude: 122° 27.9' W TO REACH TIDE STATION: To reach the tide station from the intersection of U.S. Highway 101 (north) and Lincoln Boulevard (last exit before the Golden Gate toll plaza), proceed NE on Lincoln Boulevard approximately 0.6 km (1.0 mile) to Cowles Street, turn left onto Cowles Street and proceed 0.3 km (0.5 mile) to McDowell Avenue, turn left onto McDowell Avenue and proceed 0.2 km (0.3 mile) to Crissey Field Avenue, turn left onto Crissey Field Avenue and proceed 0.1 km (0.2 mile) to a stop sign, turn right and then immediately left onto Mason street, proceed along the National Parks Service parking lot fence where Mason Street turns into Hamilton Street, and proceed 0.2 km (0.3 mile) to a parking lot at the end of the street. The tide station is located in the 2nd building on the L-shaped wooden pier formerly owned by the U.S. Coast Guard, now owned by the National Park Service. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 180 1936 MONUMENTATION: Survey Disk VM#: 967 AGENCY: PID#: HT0702 SETTING CLASSIFICATION: Concrete Seawall The primary bench mark is set in the top of a 0.9-m (3') high concrete seawall at the NW end of Crissy Field on the Coast Guard property, 15 m (49') east of the NE corner of the crews quarters building, 6 m (20') south of the south side of the garage building, and 1.1 m (3.5') north of an angle in the seawall. BENCH MARK STAMPING: BM 174 1925 MONUMENTATION: Survey Disk VM#: 971 AGENCY: PID#: HT0697 SETTING CLASSIFICATION: Concrete Monument The bench mark is set in a concrete monument level with the ground inside a brick circle in the pavement at the center of the Y-junction between Marine Drive and the road leading SE to Fort Winfield Scott, 38 m (125') west of the extension of the west edge of the engineer's dock where it crosses Marine Drive, 13.0 m (42.5') SW of a fire hydrant, and 8.7 m (28.5') south of the south edge of an iron manhole cover.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 PUBLICATION DATE: 06/06/1996 Station ID: 9414290 SUPERCEDED DATE: 04/21/2003 Name: THE PRESIDIO, SAN FRANCISCO CALIFORNIA NOAA Chart: 18649 Latitude: 37° 48.4' N USGS Quad: SAN FRANCISCO NORTH Longitude: 122° 27.9' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: BM 176 1925 MONUMENTATION: Survey Disk VM#: 972 AGENCY: PID#: HT0705 SETTING CLASSIFICATION: Concrete Step The bench mark is set in the west end of the lowest concrete step at the main entrance to the porch of the U.S. Army Logistic Control office at #651 Mason Avenue, 30 m (98') SE of the intersection of Crissy Field and Mason Avenues, 15 m (50') south of the centerline of Mason Avenue, and about 0.2 m (0.7') above the sidewalk. BENCH MARK STAMPING: 181 1945 MONUMENTATION: Survey Disk VM#: 973 AGENCY: PID#: HT0701 SETTING CLASSIFICATION: Concrete Seawall The bench mark is set in the top of the NW corner of a seawall at the Fort Point Coast Guard Station, 62 m (204') west of the inshore end of the Coast Guard wharf, 46 m (151') NW of a flagpole, 22 m (71') NE of the north corner of Building S.F. 19.4 (paint shop and storage building), and 1.2 m (4.0') above grade. BENCH MARK STAMPING: NO 2 1948 MONUMENTATION: Survey Disk VM#: 975 AGENCY: PID#: HT0700 SETTING CLASSIFICATION: Concrete Seawall The bench mark is set flush in the top of a concrete seawall, 11.4 m (37.5') west of the west edge of the engineer's dock, 8.1 m (26.5') NE of the NE corner of corrugated iron building #985, and about 0.9 m (3.0') above ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 PUBLICATION DATE: 06/06/1996 Station ID: 9414290 SUPERCEDED DATE: 04/21/2003 Name: THE PRESIDIO, SAN FRANCISCO CALIFORNIA NOAA Chart: 18649 Latitude: 37° 48.4' N USGS Quad: SAN FRANCISCO NORTH Longitude: 122° 27.9' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: CLARK 1948 MONUMENTATION: Survey Disk VM#: 976 AGENCY: PID#: HT0698 SETTING CLASSIFICATION: Concrete Seawall The bench mark is set in the top of a concrete seawall, about 549 m (1800') NW of the Fort Point Coast Guard station, 24.2 m (79.5') west of the west edge of the engineer's dock, 6.9 m (22.5') NE of the NW corner of corrugated iron building #985, 3.0 m (10') west of the NW corner of a stucco paint locker building, and about 1.1 m (3.6') above ground. BENCH MARK STAMPING: 4290 J 1976 MONUMENTATION: Survey Disk VM#: 977 AGENCY: PID#: HT2256 SETTING CLASSIFICATION: Copper Clad Steel Rod The bench mark is in an elevated beach area midway between the Fort Point Coast Guard pier and the engineer's dock, 133 m (435') WNW of the west end of the seawall surrounding the Coast Guard crews quarters, 27 m (89') SW of the shoreward end of the old seaplane ramp, 18.3 m (60.0') SE of the shoreward end of the concrete discharge pipe, and 0.8 m (2.5') north of a chain link fence surrounding U.S. Army Field Maintenance Building #937. The mark is crimped to a copper-clad steel rod driven 15 m (48'), encased in a 4-inch diameter PVC pipe, and marked by a witness post.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 PUBLICATION DATE: 06/06/1996 Station ID: 9414290 SUPERCEDED DATE: 04/21/2003 Name: THE PRESIDIO, SAN FRANCISCO CALIFORNIA NOAA Chart: 18649 Latitude: 37° 48.4' N USGS Quad: SAN FRANCISCO NORTH Longitude: 122° 27.9' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4290 K 1976 MONUMENTATION: Survey Disk VM#: 978 AGENCY: PID#: HT2255 SETTING CLASSIFICATION: Bedrock The bench mark is set vertically in bedrock on the south side of Marine Drive, 24 m (79') SSW of the SE corner of National Park Service building #T989, 14.7 m (48.2') SW of Bench Mark 174 1925, and 2.4 m (8.0') south of the south curb of Marine Drive. BENCH MARK STAMPING: BM 175 1925 MONUMENTATION: Survey Disk VM#: 1829 AGENCY: PID#: HT0696 SETTING CLASSIFICATION: Concrete Seawall The bench mark is set in the seawall near the National Park Service building, 62.2 m (214') NE of Bench Mark 4290 L 1976, 59 m (193') west of the NW corner of the park service building, 28.9 m (94.8') WNW of the northernmost post of a pedestrian gate, 6.9 m (22.5') north of the centerline of Marine Drive, and 0.7 m (2.4') south of the north edge of the seawall. (Note: The seawall was repaired in April 1981 and the elevation of the bench mark was changed after the repair, but the elevation seems stable since then.)
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 PUBLICATION DATE: 06/06/1996 Station ID: 9414290 SUPERCEDED DATE: 04/21/2003 Name: THE PRESIDIO, SAN FRANCISCO CALIFORNIA NOAA Chart: 18649 Latitude: 37° 48.4' N USGS Quad: SAN FRANCISCO NORTH Longitude: 122° 27.9' W T I D A L D A T U M S Tidal datums at THE PRESIDIO, SAN FRANCISCO based on: LENGTH OF SERIES: 19 YEARS TIME PERIOD: 1960-1978 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (01/27/1983) = 8.87 MEAN HIGHER HIGH WATER MHHW = 5.83 MEAN HIGH WATER MHW = 5.23 MEAN TIDE LEVEL MTL = 3.18 MEAN SEA LEVEL MSL = 3.13 MEAN LOW WATER MLW = 1.13 * North American Vertical Datum NAVD88 = 0.14 MEAN LOWER LOW WATER MLLW = 0.00 LOWEST OBSERVED WATER LEVEL (12/17/1933) = -2.67 * NAVD is based on elevations published in Quad 371221, 1993, and NOS leveling of 1995. North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 180 1936 13.24 8.01 BM 174 1925 16.65 11.42 BM 176 1925 15.99 10.76 181 1945 13.29 8.06 NO 2 1948 14.04 8.81 CLARK 1948 14.08 8.85 4290 J 1976 11.18 5.95 4290 K 1976 19.31 14.08 BM 175 1925 13.84 8.61
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 PUBLICATION DATE: 06/06/1996 Station ID: 9414290 SUPERCEDED DATE: 04/21/2003 Name: THE PRESIDIO, SAN FRANCISCO CALIFORNIA NOAA Chart: 18649 Latitude: 37° 48.4' N USGS Quad: SAN FRANCISCO NORTH Longitude: 122° 27.9' W 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 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.