Recording River Stage - Why, When, and How

Why:

The USGS is developing a "rating curve" for each of the 4 Upper Wallkill sites. These rating curves relate the height (stage) of the river or stream to how much water is passing the site in a given amount of time (discharge). By knowing the concentration of a particular constituent of interest (in this case TSS) and the discharge, you can calculate how much of that constituent (the mass flux) is passing the sample point at the time the TSS sample was collected.

Discharge * Concentration = Mass per unit Time

When:

A stage should be recorded immediately before and after a sample is collected. The average of these values should be associated with the sample.

How:

Stage is measured by 3 different methods at the 4 sites. Staff plates are used at Rutgers Creek and the Wallkill River at Unionville. A close-up of a staff plate is shown below:



Record the plate value to the nearest hundredth of a foot where the water surface intersects the plate. A pair of binoculars may be useful to read the plate from the bridge deck.

Pochuck Creek requires use of a wire weight gage to determine stage - instructions and pictures are available here

Wallkill River near Phillipsburg requires use of a steel measuring tape from a point on the bridge with a known elevation. Contact George Pierpoint at the Orange County Golf Club for details.

U.S. Department of the Interior, U.S. Geological Survey Maintainer: New York District URL: http://ny.water.usgs.gov/projects/wallkill/pics/staffplate.html Last update: 15:32:46 Monday 17 June 2002 Privacy Statement || Disclaimer