U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 9440574 PUBLICATION DATE: 01/06/2004 Name: NORTH JETTY WA NOAA Chart: 18521 Latitude: 46° 16.4' N ( 46.27330) USGS Quad: CAPE DISAPPOINTMENT Longitude: 124° 4.3' W (-124.07200) To reach the tidal bench marks from the center of town of Ilwaco (where U.S. Highway 101 marks a turn to north), proceed west one block and turn left at sign CAPE DISAPPOINTMENT, continue south for 2.7 km (1.7 mi) to "Y" intersection, turn left, and continue for 0.8 km (0.5 mi) to the entrance of Fort Canby State Park; turn right into the park and proceed 2.1 km (1.3 mi) to a parking lot on the left. The bench marks are located on the jetty east of the parking lot and along the road between the parking lot and the camping area. The tide gage and staff were located on the top of the rock jetty SE of the parking lot. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 0574 A 1982 DESIGNATION: 944 0574 A TIDAL MONUMENTATION: Tidal Station disk VM#: 8938 AGENCY: National Ocean Survey (NOS) IDB PID#: SD0299 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 46° 16.4' N ( 46.27330) LONGITUDE: 124° 4.4' W (-124.07300) The primary bench mark is a disk located along the south side of the Jetty Road in Fort Canby State Park, 1.9 km (1.2 mi) west along the jetty road from the park entrance, 50 m (163 ft) east of the east edge of an entrance road into a parking lot south of the Jetty Road, 7 m (23 ft) south of the south edge of the jetty road, and 1 m (3 ft) NW of a witness post. The bench mark is set 6 cm (0.2 ft) below the ground, crimped to the top of a stainless steel rod driven 14.6 m (48 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 9440574 PUBLICATION DATE: 01/06/2004 Name: NORTH JETTY WA NOAA Chart: 18521 Latitude: 46° 16.4' N ( 46.27330) USGS Quad: CAPE DISAPPOINTMENT Longitude: 124° 4.3' W (-124.07200) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0574 B 1982 DESIGNATION: 944 0574 B TIDAL MONUMENTATION: Tidal Station disk VM#: 8939 AGENCY: National Ocean Survey (NOS) IDB PID#: SD0298 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 46° 16.4' N ( 46.27330) LONGITUDE: 124° 4.3' W (-124.07200) The bench mark is a disk located along the south side of the jetty road in Fort Canby State Park, 1.6 km (1.0 mi) west along jetty road from the park entrance, 8 m (27 ft) south of the southern edge of the jetty road, and 1 m (2 ft) NW of a witness post. The bench mark is set 15 cm (0.5 ft) below the ground, crimped to the top of a stainless steel rod driven 14.6 m (48 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: 0574 C 1982 DESIGNATION: 944 0574 C TIDAL MONUMENTATION: Tidal Station disk VM#: 8940 AGENCY: National Ocean Survey (NOS) IDB PID#: SD0297 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 46° 16.6' N ( 46.27670) LONGITUDE: 124° 4.0' W (-124.06700) The bench mark is a disk located along the south side of the jetty road in Fort Canby State Park, 1.1 km (0.7 mi) west along the jetty road from the park entrance, 3 m (11 ft) south of the southern edge of jetty road, and 1 m (2 ft) NW of a witness post. The bench mark is set 15 cm (0.5 ft) below the ground, crimped to the top of a stainless steel rod driven 13.4 m (44 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 9440574 PUBLICATION DATE: 01/06/2004 Name: NORTH JETTY WA NOAA Chart: 18521 Latitude: 46° 16.4' N ( 46.27330) USGS Quad: CAPE DISAPPOINTMENT Longitude: 124° 4.3' W (-124.07200) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0574 D 1982 DESIGNATION: 944 0574 D TIDAL MONUMENTATION: Tidal Station disk VM#: 8941 AGENCY: National Ocean Survey (NOS) IDB PID#: SD0296 SETTING CLASSIFICATION: Concrete bunker OPUS PID: LATITUDE: 46° 16.9' N ( 46.28170) LONGITUDE: 124° 3.4' W (-124.05700) The bench mark is a disk set in the NW corner of a World War II machine gun bunker, 45 m (146 ft) SE of the SE corner of the restroom building, 0.3 m (1 ft) east of the west edge of the 2 m (8ft) square concrete bunker, 0.27 m (0.9 ft) south of the north edge of the bunker, and 1.16 m (3.8 ft) above the ground. BENCH MARK STAMPING: BM 1 1958 DESIGNATION: 944 0574 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 8942 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SD0302 SETTING CLASSIFICATION: Boulder OPUS PID: LATITUDE: 46° 16.3' N ( 46.27170) LONGITUDE: 124° 4.3' W (-124.07200) The bench mark is a disk set in the top of a large light colored rock located at the edge of the Columbia River, 69 m (225 ft) east of the parking lot, 3 m (10 ft) towards the river from a set of burned-out pilings, and 3 m (10 ft) below the top of a levee. Note: The high point on the disk is "R" in MARK.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 9440574 PUBLICATION DATE: 01/06/2004 Name: NORTH JETTY WA NOAA Chart: 18521 Latitude: 46° 16.4' N ( 46.27330) USGS Quad: CAPE DISAPPOINTMENT Longitude: 124° 4.3' W (-124.07200) T I D A L B E N C H M A R K S BENCH MARK STAMPING: BM 3 1958 DESIGNATION: 944 0574 TIDAL 3 MONUMENTATION: Tidal Station disk VM#: 8944 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SD0300 SETTING CLASSIFICATION: Boulder OPUS PID: LATITUDE: 46° 16.3' N ( 46.27170) LONGITUDE: 124° 4.3' W (-124.07200) The bench mark is a disk set in the top of a large jetty rock located at the edge of the Columbia River, 82 m (270 ft) east of the parking lot, 7 m (23 ft) NE of bench mark BM 2 1958, and 3 m (10 ft) below the top of a levee. Note: The high point on the disk is "D" in GEODETIC.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 9440574 PUBLICATION DATE: 01/06/2004 Name: NORTH JETTY WA NOAA Chart: 18521 Latitude: 46° 16.4' N ( 46.27330) USGS Quad: CAPE DISAPPOINTMENT Longitude: 124° 4.3' W (-124.07200) T I D A L D A T U M S Tidal datums at NORTH JETTY based on: LENGTH OF SERIES: 4 MONTHS TIME PERIOD: July 1983 - October 1983 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9439040 ASTORIA, TONGUE POINT, COLUMBIA RIVER Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 2.361 MEAN HIGH WATER MHW = 2.156 MEAN TIDE LEVEL MTL = 1.265 MEAN SEA LEVEL MSL = 1.246 MEAN LOW WATER MLW = 0.374 North American Vertical Datum NAVD88 = 0.077 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 0574 A 1982 4.949 2.793 0574 B 1982 4.782 2.626 0574 C 1982 4.754 2.598 0574 D 1982 7.447 5.291 BM 1 1958 5.900 3.744 BM 3 1958 4.327 2.171
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 9440574 PUBLICATION DATE: 01/06/2004 Name: NORTH JETTY WA NOAA Chart: 18521 Latitude: 46° 16.4' N ( 46.27330) USGS Quad: CAPE DISAPPOINTMENT Longitude: 124° 4.3' W (-124.07200) 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.