U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 7 Station ID: 8772447 PUBLICATION DATE: 04/20/2020 Name: FREEPORT, FREEPORT HARBOR CHANNEL TX NOAA Chart: 11330 Latitude: 28° 56.6' N ( 28.94331) USGS Quad: FREEPORT Longitude: 95° 18.1' W ( -95.30250) To reach the SPIP from the intersection of highway 332 and Fort Velasco Drive in Surfside, Texas proceed southwest on Fort Velasco Drive For 1.59 KM (0.99 MI) then turn left onto Park View Road and proceed 0.29 KM (0.18 MI) to surf drive and make a right to proceed into Surfside Jetty Park. The bench marks are located in the grassy area in the park and along the jetty walkway, and the SPIP is located just west of the jetty. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 2447 A 2006 DESIGNATION: 877 2447 A TIDAL ALIAS: 2447 A MONUMENTATION: Flange-encased Rod VM#: 18442 AGENCY: Conrad Blucher Institute (CBI) IDB PID: SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBGD50 LATITUDE: 28° 56.6' N ( 28.94333) LONGITUDE: 95° 18.1' W ( -95.30250) The primary bench mark is a flange-encased rod located on the USCG Freeport property, 9.6 m (31.5 ft) east along the driveway leading to the finger pier on the southernmost side of the station, 1.67 m (5.479 ft) north of the fence on the southernmost side of the station, and 0.72 m (2.4 ft) south of the southernmost concrete driveway leading to the finger pier of the southernmost side of the station adjacent to the Freeport Entrance Channel. The bench mark is set 0.100 m (0.328 ft) below grade, driven 13.4 m (44.0 ft) to refusal, and is encased in a 0.60 m (1.97 ft) PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 7 Station ID: 8772447 PUBLICATION DATE: 04/20/2020 Name: FREEPORT, FREEPORT HARBOR CHANNEL TX NOAA Chart: 11330 Latitude: 28° 56.6' N ( 28.94331) USGS Quad: FREEPORT Longitude: 95° 18.1' W ( -95.30250) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 2447 B 2006 DESIGNATION: 877 2447 B TIDAL ALIAS: 2447 B MONUMENTATION: Tidal Station disk VM#: 18443 AGENCY: Conrad Blucher Institute (CBI) IDB PID: SETTING CLASSIFICATION: Retaining wall OPUS PID: LATITUDE: 28° 56.6' N ( 28.94367) LONGITUDE: 95° 18.2' W ( -95.30278) The bench mark is a disk set on top of the NW most point of the north retaining wall of the boat ramp , 17.20 m (56.4 ft) ENE of a concrete fuel tank, 0.42 m (1.38 ft) east of the NW end of the retaining wall. BENCH MARK STAMPING: 2447 C 2006 DESIGNATION: 877 2447 C TIDAL ALIAS: 2447 C MONUMENTATION: Flange-encased Rod VM#: 18444 AGENCY: Conrad Blucher Institute (CBI) IDB PID: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 28° 56.7' N ( 28.94417) LONGITUDE: 95° 18.2' W ( -95.30311) The bench mark is a flange-encased rod located inside the north fence of the USSCG Freeport property, 27 m (88.6 ft) NNE of a light pole, 24.2 m (79.4 ft) NW of the PLCO well water tank No. 10691, and 0.9 m (2.95 ft) east of the fence line. The bench mark is driven 11 m (36.1 ft) and encased in a 6 inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 7 Station ID: 8772447 PUBLICATION DATE: 04/20/2020 Name: FREEPORT, FREEPORT HARBOR CHANNEL TX NOAA Chart: 11330 Latitude: 28° 56.6' N ( 28.94331) USGS Quad: FREEPORT Longitude: 95° 18.1' W ( -95.30250) T I D A L B E N C H M A R K S BENCH MARK STAMPING: USCG 1997 DESIGNATION: USCG ALIAS: USCG MONUMENTATION: Bench Mark disk VM#: 18445 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 28° 56.7' N ( 28.94444) LONGITUDE: 95° 18.2' W ( -95.30278) The bench mark is a disk set on top of 0.3 m x 0.3 m (1.0 ft x 1.0 ft) concrete monument, 31 m (101.7 ft) NE of the AC cooling unit at the NE corner of the maintenance building, 30.6 m (100.4 ft) south of the north fence line, and 4.35 m (14.27 ft) NE of a radio supression antenna located NE of the maintenance building, and 0.7 m (2.3 ft) above ground level. BENCH MARK STAMPING: 2447 E 2006 DESIGNATION: 877 2447 E TIDAL ALIAS: 2447 E MONUMENTATION: Flange-encased Rod VM#: 18446 AGENCY: Conrad Blucher Institute (CBI) IDB PID#: DP0699 SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: DP0699 LATITUDE: 28° 56.7' N ( 28.94472) LONGITUDE: 95° 18.2' W ( -95.30306) The bench mark is flange-encased rod located on the property of the USCG Freeport, 64.6 m (211.9 ft) north from bench mark 877 2447 C, 63.40 m (20.80 ft) NNW of the USCG bench mark, and 8.22 m (27.0 ft) SW of the NW fence corner. The datum point is set 0.1 m (0.3 ft) below grade crimped to a stainless steel rod driven 14.2 m (46.6 ft) to refusal and encased in a 0.6 m (2.0 ft) PVC pipe with a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 7 Station ID: 8772447 PUBLICATION DATE: 04/20/2020 Name: FREEPORT, FREEPORT HARBOR CHANNEL TX NOAA Chart: 11330 Latitude: 28° 56.6' N ( 28.94331) USGS Quad: FREEPORT Longitude: 95° 18.1' W ( -95.30250) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 2447 A 2 2016 DESIGNATION: 877 2447 A 2 MONUMENTATION: Tidal Station disk VM#: 21975 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Concrete sidewalk OPUS PID: LATITUDE: 28° 56.3' N ( 28.93756) LONGITUDE: 95° 17.7' W ( -95.29564) The bench mark disk is located 18.3 m (60.0 ft) south SW of the first concrete light pole coming from the jetty, 2.28 m (7.5 ft) east of a wooden hand rail on the western edge of the jetty walk way, and 0.09 m (0.3 ft) SW of the eastern edge of the concrete walk way. BENCH MARK STAMPING: 2447 B 2 2016 DESIGNATION: 877 2447 B 2 MONUMENTATION: Flange-encased Rod VM#: 21976 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 28° 56.3' N ( 28.93844) LONGITUDE: 95° 17.8' W ( -95.29617) The bench mark is a stainless steel rod located 26.7 m (87.6 ft) NW of the third wooden light pole from the jetty in the center of the park, 18 m (59.1 ft) NE of the fourth concrete light pole from the jetty on the western side of the park, 11.4 m (37.4 ft) SW of the sidewalk running north to south along the parking lot, and 9 m (29.5 ft) SSW of a witness post. The datum point is set flush with the ground, being the top of a stainless steel rod driven 9.8 m (33.0 ft) to refusal and encased in a 5 inch NOS logo cap.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 7 Station ID: 8772447 PUBLICATION DATE: 04/20/2020 Name: FREEPORT, FREEPORT HARBOR CHANNEL TX NOAA Chart: 11330 Latitude: 28° 56.6' N ( 28.94331) USGS Quad: FREEPORT Longitude: 95° 18.1' W ( -95.30250) T I D A L B E N C H M A R K S BENCH MARK STAMPING: RR 455 1951 DESIGNATION: RR 455 MONUMENTATION: Survey disk VM#: 21979 AGENCY: US Coast and Geodetic Survey IDB PID#: AM0093 SETTING CLASSIFICATION: Concrete block OPUS PID: LATITUDE: 28° 56.5' N ( 28.94242) LONGITUDE: 95° 17.8' W ( -95.29650) The benchmark is a disk set atop a concrete monument that is flush with the ground located 15 m (49.2 ft) NNE of the centerline of Thunder Road, 8 m (26.2 ft) ESE of the centerline of fort Velasco drive, 2 m (6.5 ft) NNW of a red fire hydrant, 0.85 m (2.8 ft) east of a witness post.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 7 Station ID: 8772447 PUBLICATION DATE: 04/20/2020 Name: FREEPORT, FREEPORT HARBOR CHANNEL TX NOAA Chart: 11330 Latitude: 28° 56.6' N ( 28.94331) USGS Quad: FREEPORT Longitude: 95° 18.1' W ( -95.30250) T I D A L D A T U M S Tidal datums at FREEPORT, FREEPORT HARBOR CHANNEL based on: LENGTH OF SERIES: 10 YEARS TIME PERIOD: 12/06-11/07, 10/08-9/14, 2/15-1/18 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 (09/12/2008) = 2.256 MEAN HIGHER HIGH WATER MHHW = 0.502 MEAN HIGH WATER MHW = 0.459 MEAN SEA LEVEL MSL = 0.274 MEAN TIDE LEVEL MTL = 0.269 North American Vertical Datum NAVD88 = 0.184 MEAN LOW WATER MLW = 0.078 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (03/22/2010) = -0.821 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 2447 A 2006 1.579 1.120 2447 B 2006 2.161 1.702 2447 C 2006 1.552 1.093 USCG 1997 2.756 2.297 2447 E 2006 1.805 1.346 2447 A 2 2016 2.708 2.249 2447 B 2 2016 2.625 2.166 RR 455 1951 1.282 0.823
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 7 Station ID: 8772447 PUBLICATION DATE: 04/20/2020 Name: FREEPORT, FREEPORT HARBOR CHANNEL TX NOAA Chart: 11330 Latitude: 28° 56.6' N ( 28.94331) USGS Quad: FREEPORT Longitude: 95° 18.1' W ( -95.30250) 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.