Gaging stations

Rosman Gaging Station

Gaging stations are facilities used by hydrologists to monitor streams, rivers, lakes or other bodies of water.  Instruments at these stations collect information such as water height, discharge and water chemistry and temperature.

The US Geological Survey has gaging stations at thousands of locations across the United States.  Measurements from these stations are useful for flood prediction, water management, and recreation and navigation purposes. 

Transylvania County has gaging stations on the French Broad River at Rosman and Blantyre.  There was also a gaging station on the south side of the French Broad River at Calvert until 1955.  On the Davidson River there is a gaging station located downstream from Sycamore Flats.

Calvert Gaging Station

The small concrete structures at Calvert and Davidson River were constructed using WPA funds in 1934.  The buildings are quite small, about 3 feet square.  Both have an art deco look to their poured concrete exteriors.  They contain vents with slats or louvers and narrow metal doors.  A small window allows some light into the Calvert structure as well.

The Rosman station was built in 1935 but is much plainer.  The small frame structure, with a simple wooden walkway, is raised on a cinder block foundation.  A trapdoor in the foundation provides access to the measuring panel.

The Blantyre station is a cinderblock building constructed in the 1950s.  Access is from metal ladder attached to the bridge and then across a wood and metal suspension walking bridge.

Measuring sticks or staff gages, which were basically giant rulers, measured the height of the water above a fixed point.  Stage values could be converted into discharge values for the stream.  The old gages would have been read manually.

Flood stage at Rosman is 9 feet.  The highest recorded stage was 14.95 feet on October 4, 1964.  The drainage area covers nearly 68 square miles. 

Blantyre Gaging Station

At Blantyre the drainage area is 296 square miles and flood stage is 16 feet.  The record at Blantyre is 27.10 feet on July 16, 1916.

The drainage area for the Davidson River site covers 40 square miles.  Flood stage is 9 feet, with the highest recorded stage at 12.08 on August 17, 1994.

Today measurements are computerized.  Data is recorded at 15-to-60-minute intervals and transmitted to USGS offices every 1 to 4 hours, although it may be more frequent during critical events.  Information is available online at waterdata.usgs.gov/nwis/rt for the Blantyre, Rosman and Davidson River sites.

Photographs and information for this column are provided by the Rowell Bosse North Carolina Room, Transylvania County Library.  Visit the NC Room during regular library hours (Monday-Friday) to learn more about our history and see additional photographs.  For more information, comments or suggestions contact Marcy at marcy.thompson@transylvaniacounty.org or 828-884-3151 x242.