New Streamgage Technology Saves Time and Money

By Donita Turk

Equipment used for monitoring stream levels has changed significantly in the last 10 years. In the 1980's, stream water levels (known as "stage") were measured using stilling wells and mercury manometers. The resulting equipment shelter (the gage house) was large and expensive. The stage of a river had to be recorded on graphic charts and paper tapes, which were collected from the individual gaging stations about every 6 weeks.

In the 1990's, mercury manometers were replaced by electronic stage sensors that are much smaller in size. The graphic charts and paper tapes have been replaced by data-collection platforms (DCPs) that record and transmit data via satellite to USGS field offices, where they can be made available in near real time on the Internet.

Beginning around 2000, radar stage sensors and more compact DCPs are in use at selected gaging stations. Because the radar and DCP are light and compact, they can easily be attached directly and unobtrusively to bridges or other existing structures, negating the need to build a gage house and thus saving time and money.