U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 PUBLICATION DATE: 01/14/2000 Station ID: 8771013 SUPERCEDED DATE: 04/21/2003 Name: EAGLE POINT, GALVESTON BAY TEXAS NOAA Chart: 11327 Latitude: 29° 28.8' N USGS Quad: TEXAS CITY Longitude: 94° 55.1' W To reach the tidal bench marks from the Post Office in San Leon, head south on 9th Street for 1.4 km (0.9 mi) to Avenue I, then turn east on Avenue I for 0.6 km (0.4 mi) to 5th Street., then turn south on 5th Street and go approximately 183 m (600 ft) to "Butler's on the Bay" hotel. The bench marks are located in the vicinity of the pier and along 5th Street. The tide gauge is located on the pier opposite the hotel, mounted on a square galvanized steel structure. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: LUB 1013 A 1992 DESIGNATION: 877 1013 A MONUMENTATION: Bench Mark disk VM#: 13445 AGENCY: Lamar Univ. Beaumont PID#: AJ4424 SETTING CLASSIFICATION: Stainless steel rod The primary bench mark is a disk located east of Butlers on the Bay Motel near the foot of a private pier, 40.51 m (132.9 ft) east of the centerline of 5th Street, 3.69 m (12.1 ft) NE of the north edge of the private pier, 3.35 m (10.9 ft) SW of a fence, and 0.70 m (2.3 ft) WNW of the bulkhead.The bench mark is set 5 cm (0.2 ft) below ground level, crimped to a stainless steel rod driven 10.7 m (35 ft) to refusal, and encased in a 6-inch PVC pipe with concrete kickblock. BENCH MARK STAMPING: LUB 1013 B 1992 DESIGNATION: 877 1013 B MONUMENTATION: Bench Mark disk VM#: 13446 AGENCY: Lamar Univ. Beaumont PID: SETTING CLASSIFICATION: Stainless steel rod The bench mark is a disk located east of Butlers on the Bay Motel, 18.41 m (60.4 ft) SW of the SW corner of a house, 6.77 m (22.2 ft) ESE of the centerline of 5th Street, and 0.82 m (2.7 ft) NE of a wood utility pole. The bench mark is set 5 cm (0.2 ft) below ground level, crimped to a stainless steel rod driven 10.7 m (35 ft) to refusal, and encased in a 6-inch PVC pipe with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 PUBLICATION DATE: 01/14/2000 Station ID: 8771013 SUPERCEDED DATE: 04/21/2003 Name: EAGLE POINT, GALVESTON BAY TEXAS NOAA Chart: 11327 Latitude: 29° 28.8' N USGS Quad: TEXAS CITY Longitude: 94° 55.1' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: LUB 1013 C 1992 DESIGNATION: 877 1013 C MONUMENTATION: Bench Mark disk VM#: 13447 AGENCY: Lamar Univ. Beaumont PID: SETTING CLASSIFICATION: Stainless steel rod The bench mark is a disk located 13.01 m (42.7 ft) NE of the NE corner of Butlers on the Bay Motel, 10.24 m ( 33.6 ft) north of the centerline of a gravel entrance to the motel parking area, 6.89 m (22.6 ft) west of the centerline of 5th Street, and 1.01 m (3.3 ft) SE of the end of a fence. The bench mark is set 5 cm (0.2 ft) below ground level, crimped to a stainless steel rod driven 10.7 m (35 ft) to refusal, and encased in a 6-inch PVC pipe with concrete kickblock. BENCH MARK STAMPING: LUB 1013 D 1992 DESIGNATION: 877 1013 D MONUMENTATION: Bench Mark disk VM#: 13448 AGENCY: Lamar Univ. Beaumont PID: SETTING CLASSIFICATION: Stainless steel rod The bench mark is a disk located 44 m (145 ft) NNE of bench mark LUB 1013 C 1992, 5.94 m (19.5 ft) east of the centerline of 5th Street, 1.52 m (5.0 ft) SW of a utility (gas) meter, and 1.01 m (3.3 ft) NW of a wood utility pole. The bench mark is set 5 cm (0.2 ft) below ground level, crimped to a stainless steel rod driven 10.7 m (35 ft) to refusal, and encased in a 6-inch PVC pipe with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 PUBLICATION DATE: 01/14/2000 Station ID: 8771013 SUPERCEDED DATE: 04/21/2003 Name: EAGLE POINT, GALVESTON BAY TEXAS NOAA Chart: 11327 Latitude: 29° 28.8' N USGS Quad: TEXAS CITY Longitude: 94° 55.1' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: LUB 1013 E 1992 DESIGNATION: 877 1013 E MONUMENTATION: Bench Mark disk VM#: 13449 AGENCY: Lamar Univ. Beaumont PID: SETTING CLASSIFICATION: Stainless steel rod The bench mark is a disk located at the intersection of Avenue I and 5th Street, 11.49 m (37.7 ft) north of the centerline of Avenue I, 7.28 m (23.9 ft) west of the centerline of 5th Street, and 0.73 m (2.4 ft) SSW of a wood utility pole. The bench mark is set 5 cm (0.2 ft) below ground level, crimped to a stainless steel rod driven 10.7 m (35 ft) to refusal, and encased in a 6-inch PVC pipe with concrete kickblock. BENCH MARK STAMPING: EAGLE PT NO 2 1932 DESIGNATION: EAGLE POINT RM 2 MONUMENTATION: Reference Mark disk VM#: 13450 AGENCY: USC&GS PID#: AW1602 SETTING CLASSIFICATION: Set into the top of a concrete monument The bench mark is a disk set in top of a concrete post at the intersection of 3rd Street and Avenue B at San Leon, 20.57 m (67.5 ft) SW of SW corner of a house, 9.14 m (30.0 ft) east of centerline of 3rd Street, 8.84 m (29.0 ft) north of the centerline of Avenue B, 3.20 m (10.5 ft) NE of a combination power and telephone pole, and 0.09 m (0.3 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 PUBLICATION DATE: 01/14/2000 Station ID: 8771013 SUPERCEDED DATE: 04/21/2003 Name: EAGLE POINT, GALVESTON BAY TEXAS NOAA Chart: 11327 Latitude: 29° 28.8' N USGS Quad: TEXAS CITY Longitude: 94° 55.1' W T I D A L D A T U M S Tidal datums at EAGLE POINT, GALVESTON BAY based on: LENGTH OF SERIES: 57 MONTHS TIME PERIOD: October 1993 - June 1998 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 8771450 GALVESTON PIER 21, GALVESTON CHANNEL Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (10/06/1996) = 1.082 MEAN HIGHER HIGH WATER MHHW = 0.336 MEAN HIGH WATER MHW = 0.323 MEAN SEA LEVEL MSL = 0.189 MEAN TIDE LEVEL MTL = 0.174 MEAN LOW WATER MLW = 0.025 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (12/29/1997) = -1.109 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW LUB 1013 A 1992 1.463 1.140 LUB 1013 B 1992 2.696 2.373 LUB 1013 C 1992 2.602 2.279 LUB 1013 D 1992 2.590 2.267 LUB 1013 E 1992 2.544 2.221 EAGLE PT NO 2 1932 3.085 2.762
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 PUBLICATION DATE: 01/14/2000 Station ID: 8771013 SUPERCEDED DATE: 04/21/2003 Name: EAGLE POINT, GALVESTON BAY TEXAS NOAA Chart: 11327 Latitude: 29° 28.8' N USGS Quad: TEXAS CITY Longitude: 94° 55.1' W Foot Notes: Galveston Bay, Texas has anomalous relative sea level trends compared to most other geographic regions in the United States. This is due to a general subsidence of land in this area, which has been occurring at a rapid rate. Because of the magnitude of the sea level trends in these areas, NOAA has adopted a procedure for computing accepted tidal datums for the National Water Level Observation Network (NWLON) using the last several years of sea level data rather than the 19-year tidal epoch. The tide ranges are still based on the 1960 - 1978 National Tidal Datum Epoch (NTDE) and are applied to the 5 year (1990 - 1994) mean tide level (MTL) to compute other tidal datums. The adoption of this procedure was necessary to ensure that these tidal datums accurately represent the existing stand of sea level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 PUBLICATION DATE: 01/14/2000 Station ID: 8771013 SUPERCEDED DATE: 04/21/2003 Name: EAGLE POINT, GALVESTON BAY TEXAS NOAA Chart: 11327 Latitude: 29° 28.8' N USGS Quad: TEXAS CITY Longitude: 94° 55.1' 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.