U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8771013 PUBLICATION DATE: 10/23/2020 Name: EAGLE POINT, GALVESTON BAY TX NOAA Chart: 11327 Latitude: 29° 28.8' N ( 29.48000) USGS Quad: TEXAS CITY Longitude: 94° 55.1' W ( -94.91831) To reach the tidal bench marks from the Post Office in San Leon, proceed 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 0.2 km (0.1 mi) to 909 5th St house named "The Bay". 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 E 1992 DESIGNATION: 877 1013 E ALIAS: 1013 E MONUMENTATION: Bench Mark disk VM#: 13449 AGENCY: Lamar University IDB PID#: DR3192 SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBGD05 LATITUDE: 29° 28.9' N ( 29.48238) LONGITUDE: 94° 55.1' W ( -94.91872) The primary bench mark is located at the intersection of 5th Street and Ave I in San Leon, 11.16 m (36.62 ft) N from the centerline of Ave I, 6.33 m (20.78 ft) W of the centerline of 5th Street, and 1.0 m (3.3 ft) S of a wood utility pole. The bench mark is set 5 cm below ground level, crimped to a stainless steel rod driven 10.7 m (35.10 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 5 Station ID: 8771013 PUBLICATION DATE: 10/23/2020 Name: EAGLE POINT, GALVESTON BAY TX NOAA Chart: 11327 Latitude: 29° 28.8' N ( 29.48000) USGS Quad: TEXAS CITY Longitude: 94° 55.1' W ( -94.91831) 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 ALIAS: 1013 C MONUMENTATION: Bench Mark disk VM#: 13447 AGENCY: Lamar University IDB PID: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 29° 28.9' N ( 29.48114) LONGITUDE: 94° 55.1' W ( -94.91906) The bench mark is a disk located 13.01 m (42.68 ft) NE of the NE corner of Butlers on the Bay Motel, 10.24 m ( 33.60 ft) north of the centerline of a gravel entrance to the motel parking area, 6.89 m (22.60 ft) west of the centerline of 5th Street, and 1.01 m (3.31 ft) SE of the end of a fence. The bench mark is set 5 cm below ground level, crimped to a stainless steel rod driven 10.7 m (35.1ft) to refusal, and encased in a 6-inch PVC pipe with concrete kickblock. BENCH MARK STAMPING: LUB 1013 D 1992 DESIGNATION: 877 1013 D ALIAS: 1013 D MONUMENTATION: Bench Mark disk VM#: 13448 AGENCY: Lamar University IDB PID: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 29° 28.9' N ( 29.48153) LONGITUDE: 94° 55.1' W ( -94.91882) The bench mark is a disk located 44 m (144.4 ft) NNE of bench mark LUB 1013 C 1992, 5.94 m (19.49 ft) east of the centerline of 5th Street, 1.52 m (4.987 ft) SW of a utility (gas) meter, and 1.01 m (3.31 ft) NW of a wood utility pole. The bench mark is set 5 cm below ground level, crimped to a stainless steel rod driven 10.7 m (35.1 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 5 Station ID: 8771013 PUBLICATION DATE: 10/23/2020 Name: EAGLE POINT, GALVESTON BAY TX NOAA Chart: 11327 Latitude: 29° 28.8' N ( 29.48000) USGS Quad: TEXAS CITY Longitude: 94° 55.1' W ( -94.91831) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1013 F 2002 DESIGNATION: 877 1013 F ALIAS: 1013 F MONUMENTATION: Bench Mark disk VM#: 16721 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Sidewalk OPUS PID: LATITUDE: 29° 28.9' N ( 29.48175) LONGITUDE: 94° 55.1' W ( -94.91803) The bench mark is a brass surface disk set in the concrete sidewalk that runs along the bulkhead located on the sidewalk at the bulkhead of 909 5th street in San Leon. The bench mark 0.22m (0.7 ft) NW of th edge SE edge of the bulkhead, 3.0m (9.8 ft) SE of a flag pole, 6.1m (2.0 ft) south of the SW corner of a (0.60m) 2 ft cube of concrete, and 6.1m (2.0 ft) north of the base of a 106.68m (350 ft) wooden pier. BENCH MARK STAMPING: 1013 G 2019 DESIGNATION: 877 1013 G ALIAS: 1013 G MONUMENTATION: Flange-encased Rod VM#: 23088 AGENCY: IDB PID: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 29° 28.8' N ( 29.48083) LONGITUDE: 94° 55.2' W ( -94.92028) The bench mark is located 13 m (42.7 ft) W of the centerline of Sixth Street, 8.8 m (28.9 ft) WNW of a manhole cover at the corner of Sixth Street and Avenue J, 6.35 m (20.8 ft) N of the centerline of Avenue J, and 1.9 m (6.2 ft) ESE of an orange witness post located below guywire for a power pole. The bench mark is a stainless steel rod driven 9.7 m (31.8 ft) encased in a 6 inch (15 cm) PVC pipe with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8771013 PUBLICATION DATE: 10/23/2020 Name: EAGLE POINT, GALVESTON BAY TX NOAA Chart: 11327 Latitude: 29° 28.8' N ( 29.48000) USGS Quad: TEXAS CITY Longitude: 94° 55.1' W ( -94.91831) T I D A L D A T U M S Tidal datums at EAGLE POINT, GALVESTON BAY based on: LENGTH OF SERIES: 22 YEARS TIME PERIOD: 09/94-08/08, 02/10-01/14, 01/15-12/18 TIDAL EPOCH: 1983-2001 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 (09/13/2008) = 3.602 MEAN HIGHER HIGH WATER MHHW = 0.341 MEAN HIGH WATER MHW = 0.328 MEAN SEA LEVEL MSL = 0.184 MEAN TIDE LEVEL MTL = 0.172 MEAN LOW WATER MLW = 0.017 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (12/29/1997) = -1.194 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW LUB 1013 E 1992 2.458 2.130 LUB 1013 C 1992 2.515 2.187 LUB 1013 D 1992 2.503 2.175 1013 F 2002 2.336 2.008 1013 G 2019 2.083 1.755 Foot Notes: Bench mark 1013 G 2019 is based on one differential leveling connection and do not meet the quality control standards of the NOS. Therefore, caution should be used when deriving elevations for these marks.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8771013 PUBLICATION DATE: 10/23/2020 Name: EAGLE POINT, GALVESTON BAY TX NOAA Chart: 11327 Latitude: 29° 28.8' N ( 29.48000) USGS Quad: TEXAS CITY Longitude: 94° 55.1' W ( -94.91831) 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.