U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8571773 PUBLICATION DATE: 06/30/2010 Name: VIENNA, NANICOKE RIVER MD NOAA Chart: 12261 Latitude: 38° 29.0' N ( 38.48333) USGS Quad: MARDELA SPRINGS Longitude: 75° 49.1' W ( -75.81833) To reach the tidal bench marks from Cambridge, MD. travel East on Route 50 approximately 13 miles (20.9 KM) the Route 331exit. Head south for approximately 0.1 miles (.16 KM) and turn east onto Chapel of Ease Road. Follow road for approximately 0.2 miles (0.3 KM) to entrance of NRG Vienna power plant. Continue through gate approximately 0.2 miles (0.3 KM) to power plant facility. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: X5 RESET 1964 DESIGNATION: 857 1773 X5 RESET MONUMENTATION: Tidal Station disk VM#: 17826 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: HU0640 SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 38° 29.1' N ( 38.48530) LONGITUDE: 75° 49.3' W ( -75.82130) The benchmark is set in the south corner of the concrete foundation of the south western metal leg of the more easterly of two towers whose power lines cross the Nanticoke River, 17.10 m (56.1 ft) SE from drainage valve 007, 1.25 m (4.10 ft) south of the south leg of the tower, 0.49 m (1.6 ft) north of the south corner of the foundation, and 0.61 m (2.0 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8571773 PUBLICATION DATE: 06/30/2010 Name: VIENNA, NANICOKE RIVER MD NOAA Chart: 12261 Latitude: 38° 29.0' N ( 38.48333) USGS Quad: MARDELA SPRINGS Longitude: 75° 49.1' W ( -75.81833) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1773 A 2005 DESIGNATION: 857 1773 A MONUMENTATION: Tidal Station disk VM#: 17827 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete footing OPUS PID: LATITUDE: 38° 29.1' N ( 38.48540) LONGITUDE: 75° 49.3' W ( -75.82150) The bench mark is set into the concrete footing of a light pole, located at the southern end of the property, along the Nanticoke River, north of a small wooden pier, 28.59 m (93.8 ft) east of the SE corner of a metal tower with 2 cameras on top, 19.11 m (62.7 ft) NE of a single yellow bollard, 11.00 m (36.1 ft) SW of the south westerly of the 2 yellow bollards, 0.39 m (1.28 ft) west of center light pole, and 0.24 m (0.79 ft) above the ground. BENCH MARK STAMPING: 1773 B 2005 DESIGNATION: 857 1773 B MONUMENTATION: Tidal Station disk VM#: 17828 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete bulkhead OPUS PID: LATITUDE: 38° 29.1' N ( 38.48580) LONGITUDE: 75° 49.3' W ( -75.82090) The bench mark a disk set into the concrete bulkhead running the length of the Nanticoke River, 40.94 m (134.13 ft) south of a single 62 cm diameter yellow bollard, 11.97 m (39.27 ft) east of the north corner of a blue 2-story concrete block building., and 0.80 m (2.62 ft) west from riverside face of concrete bulkhead.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8571773 PUBLICATION DATE: 06/30/2010 Name: VIENNA, NANICOKE RIVER MD NOAA Chart: 12261 Latitude: 38° 29.0' N ( 38.48333) USGS Quad: MARDELA SPRINGS Longitude: 75° 49.1' W ( -75.81833) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1773 C 2005 DESIGNATION: 857 1773 C MONUMENTATION: Tidal Station disk VM#: 17829 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete bulkhead OPUS PID: LATITUDE: 38° 29.2' N ( 38.48620) LONGITUDE: 75° 49.2' W ( -75.82040) The benchmark is set into the concrete bulkhead along the Nanticoke River, 13.83 m (45.37 ft) east of the centerline from a single yellow bollard, 5.91 m (19.4 ft) south from the north corner of the support leg of a steel shelter, and 0.75 m (2.46 ft) north west of riverside face of concrete bulkhead. BENCH MARK STAMPING: 1773 D 2005 DESIGNATION: 857 1773 D MONUMENTATION: Tidal Station disk VM#: 17830 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 38° 29.2' N ( 38.48690) LONGITUDE: 75° 49.2' W ( -75.82020) The bench mark is set into the concrete foundation used to mount a holding tank for a caustic solution, 18.52 m (60.76 ft) WNW of riverside face of concrete bulkhead, 16.09 m (52.8 ft) SW from the NE corner of the Clearwell Building, and 15.60 m (51.18 ft) N from the NE corner of the Office Building .3m (.98 ft) above ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8571773 PUBLICATION DATE: 06/30/2010 Name: VIENNA, NANICOKE RIVER MD NOAA Chart: 12261 Latitude: 38° 29.0' N ( 38.48333) USGS Quad: MARDELA SPRINGS Longitude: 75° 49.1' W ( -75.81833) T I D A L D A T U M S Tidal datums at VIENNA, NANICOKE RIVER based on: LENGTH OF SERIES: 4 YEARS TIME PERIOD: September 2005 - August 2009 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8571892 CAMBRIDGE, CHOPTANK RIVER Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (05/12/2008) = 1.312 MEAN HIGHER HIGH WATER MHHW = 0.750 MEAN HIGH WATER MHW = 0.702 MEAN SEA LEVEL MSL = 0.406 MEAN TIDE LEVEL MTL = 0.379 MEAN LOW WATER MLW = 0.055 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (01/03/2008) = -0.617 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW X5 RESET 1964 3.473 2.771 1773 A 2005 2.905 2.203 1773 B 2005 2.259 1.557 1773 C 2005 2.252 1.550 1773 D 2005 2.785 2.083
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8571773 PUBLICATION DATE: 06/30/2010 Name: VIENNA, NANICOKE RIVER MD NOAA Chart: 12261 Latitude: 38° 29.0' N ( 38.48333) USGS Quad: MARDELA SPRINGS Longitude: 75° 49.1' W ( -75.81833) 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.