Of the many agencies that rushed to help victims of October’s floods, one remains largely unknown. It’s the U.S. Geological Survey, which maintains a network of satellite-connected guages to measure the elevation of rivers and creeks statewide. This information and more is shared with numerous agencies, and is vital to the National Weather Service, which uses it to make accurate predictions and generate flood warnings and watches when needed.
The Survey itself took a hit in October when 12 of its gauges were washed away by the floods, but thanks to help from other states’ USGS crews, the network was complete again in 24 hours.
More on this story (03/17/16):
Thanks to a long-standing partnership with the United States Geological Survey, South Carolina and other states have access to real-time and historical data of the rivers and streams mapped in the U.S.G.S. water monitoring programs. In South Carolina, there is an estimated 200 gages that comprise the hydrological monitoring program. The gages gather information (such as river elevation and flow velocity), record the measurements, and disseminate the data to the web via satellite uploads. This data is then available to county, state, and federal agencies as well as the public on the U.S.G.S. website (click here for South Carolina.)
October’s flooding damaged a dozen monitoring stations, temporarily halting data collection. But through the collaborative efforts of geological survey teams from Alabama, Georgia, North Carolina, and Tennessee, all disabled monitoring stations were back to full operation within 24 hours, including additional temporary gages to help monitor streamflow making its way to the Low Country.
What the Gages Measure
- Surface Water: This is the height of the surface of the river (opposed to the depth) to another elevated point, such as a bridge. For example, Miami Dade County in Florida is about five feet above sea level, while Denver County in Colorado is approximately one mile above sea level.
- Velocity: Velocity meters deployed in rivers and streams continuously measure the flow of a river. The relationship between the surface water height and velocity is called the streamflow rating curve, which can tell you the volume of flow at any elevation point of a creek or river.
- Water Quality: More than 50 stations measure the quality of water throughout South Carolina. Water quality parameters include temperature, conductivity, pH levels, dissolved oxygen levels, and turbidity. Determining Gage Placement
The U.S.G.S. partners with state and local agencies to determine the placeent of measuring stations. Partnering with state and local agencies is crucial for the USGS. The United States Congress has kept funding flat for the last 15 years, which has limited the USGS’s ability to install monitoring stations. Last October’s flooding in South Carolina exposed gaps in the streamflow monitoring network. With more monitoring stations in the network, state and local agencies would have better, more accurate information to use when preparing for future events.
- View the Streamflow Data Report from the U.S.G.S.: Preliminary Peak Stage and Streamflow Data at Selected USGS Streamgaging Stations for the South Carolina Flood of October 2015