U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9434938 PUBLICATION DATE: 05/23/2003 Name: DRIFT CREEK, ALSEA RIVER OR NOAA Chart: 18561 Latitude: 44° 24.8' N ( 44.41330) USGS Quad: TIDEWATER Longitude: 123° 59.4' W (-123.99000) To reach the tidal bench marks from the intersection of U.S. Highway 101 and State Highway 34 in Waldport, proceed east on State Highway 34 for about 8 km (5 mi) to 4015 Highway 34 and Drift Creek Boat Dock on Alsea River. The bench marks are located along State Highway 34 at Oakland's Fish Camp and at Bosworths Boat Repair. The tide gage and staff were located on the Boat Dock. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 4938 B 1976 DESIGNATION: 943 4938 B MONUMENTATION: Tidal Station disk VM#: 8821 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Unspecified deep rod OPUS PID: LATITUDE: 44° 24.8' N ( 44.41330) LONGITUDE: 123° 59.4' W (-123.99000) The primary bench mark is a disk located 49 m (162 ft) north of the centerline of State Highway 34, 30.18 m (99.0 ft) east of bench mark 4938 A 1976, 21.34 m (70.0 ft) NNW of the NW corner of Bosworths Boat Repair Shop, 0.61 m (2.0 ft) north of a utility pole, and 0.43 m (1.4 ft) north of a metal witness post. The bench mark is set at ground level, crimped to the top of an unspecified steel rod driven to an unspecified depth, and encased in a 4-inch plastic pipe with a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9434938 PUBLICATION DATE: 05/23/2003 Name: DRIFT CREEK, ALSEA RIVER OR NOAA Chart: 18561 Latitude: 44° 24.8' N ( 44.41330) USGS Quad: TIDEWATER Longitude: 123° 59.4' W (-123.99000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4938 A 1976 DESIGNATION: 943 4938 A MONUMENTATION: Tidal Station disk VM#: 8820 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete boat ramp OPUS PID: LATITUDE: 44° 24.8' N ( 44.41330) LONGITUDE: 123° 59.4' W (-123.99000) The bench mark is a disk set flush in concrete at the SW corner of the foot of the boat ramp at Oakland's Fish Camp, 53 m (174 ft) north of the centerline of State Highway 34, 8.11 m (26.6 ft) WSW of the SW corner of a house, and 3.23 m (10.6 ft) SE of the SE corner of Oaklands Marina building. BENCH MARK STAMPING: 4938 C 1976 DESIGNATION: 943 4938 C MONUMENTATION: Tidal Station disk VM#: 8822 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 44° 24.8' N ( 44.41330) LONGITUDE: 123° 59.4' W (-123.99000) The bench mark is a disk set flush in concrete at the north side of the garage door on the west side of Bosworths Boat Repair Shop, 29.02 m (95.2 ft) SE of bench mark 4938 B 1976, and 21.64 m (71.0 ft) north of the centerline of State Highway 34.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9434938 PUBLICATION DATE: 05/23/2003 Name: DRIFT CREEK, ALSEA RIVER OR NOAA Chart: 18561 Latitude: 44° 24.8' N ( 44.41330) USGS Quad: TIDEWATER Longitude: 123° 59.4' W (-123.99000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4938 D 1976 DESIGNATION: 943 4938 D MONUMENTATION: Tidal Station disk VM#: 8823 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Unspecified deep rod OPUS PID: LATITUDE: 44° 24.8' N ( 44.41330) LONGITUDE: 123° 59.4' W (-123.99000) The bench mark is a disk located 27.13 m (89.0 ft) SW of the SW corner of Bosworths Boat Repair Shop, 11.13 m (36.5 ft) south of the centerline of State Highway 34, 3.35 m (11.0 ft) ENE of a utility pole, and 0.30 m (1.0 ft) NE of a metal witness post. The bench mark is set 0.03 m (0.1 ft) above ground level, crimped to the top of an unspecified steel rod driven to an unspecified depth to refusal, and encased in a 4-inch plastic pipe with a concrete kickblock. BENCH MARK STAMPING: 4938 E 1976 DESIGNATION: 943 4938 E MONUMENTATION: Tidal Station disk VM#: 8824 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Unspecified deep rod OPUS PID: LATITUDE: 44° 24.8' N ( 44.41330) LONGITUDE: 123° 59.4' W (-123.99000) The bench mark is a disk located 66 m (216 ft) SW of bench mark 4938 A 1976, 12.19 m (40.0 ft) north of the centerline of State Highway 34, 7.62 m (25.0 ft) east of a utility pole, and 0.52 m (1.7 ft) SE of a metal witness post. The bench mark is set 0.03 m (0.1 ft) above ground level, crimped to the top of an unspecified steel rod driven an unspecified depth to refusal, and encased in a 4-inch plastic pipe with a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9434938 PUBLICATION DATE: 05/23/2003 Name: DRIFT CREEK, ALSEA RIVER OR NOAA Chart: 18561 Latitude: 44° 24.8' N ( 44.41330) USGS Quad: TIDEWATER Longitude: 123° 59.4' W (-123.99000) T I D A L D A T U M S Tidal datums at DRIFT CREEK, ALSEA RIVER based on: LENGTH OF SERIES: 1 YEAR TIME PERIOD: January 1977 - December 1977 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9432780 CHARLESTON, COOS BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (01/05/1978) = 3.272 MEAN HIGHER HIGH WATER MHHW = 1.966 MEAN HIGH WATER MHW = 1.756 MEAN TIDE LEVEL MTL = 0.980 MEAN SEA LEVEL MSL = 0.902 MEAN LOW WATER MLW = 0.203 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (07/15/1977) = -0.337 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 4938 B 1976 5.695 3.939 4938 A 1976 3.407 1.651 4938 C 1976 5.938 4.182 4938 D 1976 7.442 5.686 4938 E 1976 5.588 3.832
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9434938 PUBLICATION DATE: 05/23/2003 Name: DRIFT CREEK, ALSEA RIVER OR NOAA Chart: 18561 Latitude: 44° 24.8' N ( 44.41330) USGS Quad: TIDEWATER Longitude: 123° 59.4' W (-123.99000) 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.