U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 7 Station ID: 8571892 PUBLICATION DATE: 02/26/2020 Name: CAMBRIDGE, CHOPTANK RIVER MD NOAA Chart: 12266 Latitude: 38° 34.5' N ( 38.57417) USGS Quad: CAMBRIDGE Longitude: 76° 4.3' W ( -76.07222) T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 1892 D 1980 DESIGNATION: 857 1892 D MONUMENTATION: Tidal Station disk VM#: 13432 AGENCY: National Ocean Survey (NOS) IDB PID#: AC6854 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 38° 34.4' N ( 38.57330) LONGITUDE: 76° 4.2' W ( -76.07000) The primary bench mark is a disk located along the east side of Hayward Street, 31.46 m (103.2 ft) west of the south corner of the Governors Hall, 28.99 m (95.1 ft) SE of the bulkhead face, 4.33 m (14.2 ft) WNW of the west corner of a storm drain, and 0.55 m (1.8 ft) NE of power pole numbered 33471-00805 with white witness post. The bench mark is set 9.1 cm (0.3 ft) below ground, crimped to the top of a stainless steel rod driven 11 m (36 ft) to refusal, and encased in a 4 inch PVC pipe with concrete kickblock. Note: Sleeve depth does not meet the specifications of a class a rod mark.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 7 Station ID: 8571892 PUBLICATION DATE: 02/26/2020 Name: CAMBRIDGE, CHOPTANK RIVER MD NOAA Chart: 12266 Latitude: 38° 34.5' N ( 38.57417) USGS Quad: CAMBRIDGE Longitude: 76° 4.3' W ( -76.07222) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1892 A 1980 DESIGNATION: 857 1892 A MONUMENTATION: Tidal Station disk VM#: 13429 AGENCY: National Ocean Survey (NOS) IDB PID#: AC6857 SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 38° 35.1' N ( 38.58500) LONGITUDE: 76° 3.8' W ( -76.06330) The bench mark is a disk located at the NW corner of the intersection of Maryland Avenue and Hayward Street, 9.24 m (30.3 ft) NW of the centerline of Hayward Street, 7.80 m (25.6 ft) NE of the centerline of Maryland Avenue, and 0.49 m (1.6 ft) north of power pole numbered 33432/00725. The bench mark is crimped to the top of a galvanized steel rod driven 9.8 m (32 ft) to refusal, and encased in a 4 inch PVC pipe with concrete kickblock. Note: Sleeve depth does not meet the specifications of a class a rod mark. BENCH MARK STAMPING: 1892 B 1980 DESIGNATION: 857 1892 B MONUMENTATION: Tidal Station disk VM#: 13430 AGENCY: National Ocean Survey (NOS) IDB PID#: AC6856 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 38° 34.3' N ( 38.57170) LONGITUDE: 76° 4.2' W ( -76.07000) The bench mark is a disk located at the NE corner of the intersection of Byrn Street and Hayward Street, 10.91 m (35.8 ft) NE of the centerline of Byrn Street, 6.55 m (21.5 ft) SE of the centerline of Hayward Street, and 0.4 m (1.3 ft) west of a light pole numbered 33453/00763. The bench mark is set 9.1 cm (0.3 ft) below ground, crimped to the top of a stainless steel rod driven 11 m (36 ft) to refusal, and encased in a 4 inch PVC pipe with concrete kickblock. Note: Sleeve depth does not meet the specifications of a class a rod mark.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 7 Station ID: 8571892 PUBLICATION DATE: 02/26/2020 Name: CAMBRIDGE, CHOPTANK RIVER MD NOAA Chart: 12266 Latitude: 38° 34.5' N ( 38.57417) USGS Quad: CAMBRIDGE Longitude: 76° 4.3' W ( -76.07222) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1892 C 1980 DESIGNATION: 857 1892 C MONUMENTATION: Tidal Station disk VM#: 13431 AGENCY: National Ocean Survey (NOS) IDB PID#: AC6855 SETTING CLASSIFICATION: Unspecified deep rod OPUS PID#: AC6855 LATITUDE: 38° 34.3' N ( 38.57170) LONGITUDE: 76° 4.2' W ( -76.07000) The bench mark is a disk located along the east side of Hayward Street, 23.07 m (75.7 ft) south of the SW corner of the brick office building, 6.71 m (22.0 ft) SE of the centerline of Hayward Street, and 0.43 m (1.4 ft) SE of power pole numbered 33459/00777. The bench mark is crimped to the top of an unspecified rod driven 7.3 m (24 ft) to refusal, and encased in a 4 inch PVC pipe with concrete kickblock. Note: Sleeve depth does not meet the specifications of a class a rod mark. BENCH MARK STAMPING: 1892 F 1980 DESIGNATION: 857 1892 F MONUMENTATION: Tidal Station disk VM#: 13434 AGENCY: National Ocean Survey (NOS) IDB PID#: DL8742 SETTING CLASSIFICATION: Concrete loading dock OPUS PID: LATITUDE: 38° 34.4' N ( 38.57330) LONGITUDE: 76° 4.1' W ( -76.06830) The bench mark is a disk set in the concrete loading dock on the east corner of the Governors Hall, 5.79 m (19.0 ft) NW of three cables for a canvas canopy, 4.21 m (13.8 ft) SE of the NE corner of the hall, 0.3 m (1 ft) SW of the NE corner of a concrete platform, and 1.13 m (3.7 ft) above ground. BENCH MARK STAMPING: BALTO MARYLAND DESIGNATION: 19 BALTO ALIAS: MONUMENTATION: Survey disk VM#: 13435 AGENCY: US Geological Survey (USGS) IDB PID#: HV0236 SETTING CLASSIFICATION: Granite foundation OPUS PID: LATITUDE: 38° 34.3' N ( 38.57170) LONGITUDE: 76° 4.6' W ( -76.07670) The bench mark is a disk set vertically in the NW face of the granite foundation for the Dorchester County Courthouse, at the intersection of High Street and Spring Street, 35.4 m (116 ft) NE of the centerline of Spring Street, 29 m (95 ft) SE of the centerline of High Street, 0.21 m (0.7 ft) NE of the west corner of the building, and 1 m (3 ft) above High Street.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 7 Station ID: 8571892 PUBLICATION DATE: 02/26/2020 Name: CAMBRIDGE, CHOPTANK RIVER MD NOAA Chart: 12266 Latitude: 38° 34.5' N ( 38.57417) USGS Quad: CAMBRIDGE Longitude: 76° 4.3' W ( -76.07222) T I D A L B E N C H M A R K S BENCH MARK STAMPING: CAM 1980 DESIGNATION: CAM 1980 MONUMENTATION: Triangulation Station disk VM#: 13823 AGENCY: US Army Corps of Engineers (USE) IDB PID#: DL8743 SETTING CLASSIFICATION: Concrete sidewalk OPUS PID: LATITUDE: 38° 34.2' N ( 38.57000) LONGITUDE: 76° 4.4' W ( -76.07330) The bench mark is a disk set in the concrete sidewalk on the SW corner of the Cambridge Creek Bridge on Maryland Avenue, 44.10 m (144.7 ft) west from the centerline of the opening of the draw bridge, 34.11 m (111.9 ft) west of the west edge of the bridge span, 15.42 m (50.6 ft) east of the bridge stoplight at the west end of the bridge, 4.83 m (15.8 ft) SSW from the centerline of the bridge road, and 0.73 m (2.4 ft) north of the concrete railing. BENCH MARK STAMPING: 1892 G 2012 DESIGNATION: 857 1892 G MONUMENTATION: Tidal Station disk VM#: 20464 AGENCY: CO-OPS IDB PID: SETTING CLASSIFICATION: Concrete pad OPUS PID: LATITUDE: 38° 34.3' N ( 38.57228) LONGITUDE: 76° 4.1' W ( -76.06789) The bench mark is a brass disc set in a concrete pad located 26.13 M (85.7 FT) southeast of power line pole #33509 on the north side of Hayward St, 20.2 M (66.3 FT) east of a red fire hydrant located on Hayward St, 7.1 M (23.3 FT) northwest of the south corner of a 7.3 M (24 FT) x 7.0 M (23 FT) concrete pad used for 2 medical oxygen tanks and is 11 inches (28 cm) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 7 Station ID: 8571892 PUBLICATION DATE: 02/26/2020 Name: CAMBRIDGE, CHOPTANK RIVER MD NOAA Chart: 12266 Latitude: 38° 34.5' N ( 38.57417) USGS Quad: CAMBRIDGE Longitude: 76° 4.3' W ( -76.07222) T I D A L B E N C H M A R K S BENCH MARK STAMPING: S 61 1942 DESIGNATION: S 61 MONUMENTATION: Bench Mark disk VM#: 22856 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: HV0002 SETTING CLASSIFICATION: Bridge abutment OPUS PID: LATITUDE: 38° 34.1' N ( 38.56889) LONGITUDE: 76° 3.8' W ( -76.06319) The mark is a brass disk set in a concrete abutment of the U.S. 50 bridge over the Choptank River, 12.8 m (42 ft) ENE of the SE corner of a placard on bricks located on the west side of the Frederick C. Malkus, Jr. Bridge, 8.38 m (27.5 ft) SW of a galvanized steel double chain link gate standing approximately 2.7 m (9 ft), 5.00 m (16.4 ft) west of the centerline of a paved road leading to the Bill Burton Fishing Pier. BENCH MARK STAMPING: 1892 H 2018 DESIGNATION: 857 1892 H MONUMENTATION: Bench Mark disk VM#: 22857 AGENCY: National Ocean Service (NOS) IDB PID: SETTING CLASSIFICATION: Bridge abutment OPUS PID: LATITUDE: 38° 34.3' N ( 38.57242) LONGITUDE: 76° 3.7' W ( -76.06175) The bench mark is a brass disk set flush in concrete located 7.0 m (23.0 ft) NNW of the SSE face of the Bill Burton Fishing Pier curb, 1.20 m (3.9 ft) SSE of the NNW of the curb, 0.61 m (2.0 ft) east of the east corner of the wind mast base plate located next to the NOAA tide enclosure, and 0.23 m (0.8 ft) above the road.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 7 Station ID: 8571892 PUBLICATION DATE: 02/26/2020 Name: CAMBRIDGE, CHOPTANK RIVER MD NOAA Chart: 12266 Latitude: 38° 34.5' N ( 38.57417) USGS Quad: CAMBRIDGE Longitude: 76° 4.3' W ( -76.07222) T I D A L D A T U M S Tidal datums at CAMBRIDGE, CHOPTANK RIVER based on: LENGTH OF SERIES: 19 YEARS TIME PERIOD: January 1983 - December 2001 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (09/19/2003) = 1.884 MEAN HIGHER HIGH WATER MHHW = 0.622 MEAN HIGH WATER MHW = 0.558 North American Vertical Datum NAVD88 = 0.337 MEAN TIDE LEVEL MTL = 0.310 MEAN SEA LEVEL MSL = 0.309 MEAN LOW WATER MLW = 0.063 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (01/17/1982) = -0.878 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 1892 D 1980 2.594 2.036 1892 A 1980 4.184 3.626 1892 B 1980 4.527 3.969 1892 C 1980 3.913 3.355 1892 F 1980 3.910 3.352 BALTO MARYLAND 6.106 5.548 CAM 1980 3.549 2.991 1892 G 2012 3.992 3.434 S 61 1942 4.214 3.656 1892 H 2018 4.187 3.629
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 7 Station ID: 8571892 PUBLICATION DATE: 02/26/2020 Name: CAMBRIDGE, CHOPTANK RIVER MD NOAA Chart: 12266 Latitude: 38° 34.5' N ( 38.57417) USGS Quad: CAMBRIDGE Longitude: 76° 4.3' W ( -76.07222) 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.