Flood Investigations

The design of highways and hydraulic structures within stream channels depends on accurate estimations of flood frequency and related debris-flow magnitude. Flood-recurrence intervals generally cannot be estimated on the basis of channel characteristics alone; long-term records of peak-flow measurements also are necessary.

Objectives

Appraise the flood frequency and magnitude of Nevada streams as they relate to the design of highways and related hydraulic structures.

Strategy and Approach

Crest-stage gages to measure peak-streamflow stages have been installed, and are being maintained and operated. Sites are visited periodically to obtain flood records, maintain equipment, and make indirect measurements. Each crest-stage site is monitored for at least 10-15 years to provide data defining flood frequency and magnitude.

Data Availability

Data collected as part of the USGS Nevada Water Science Center ground-water network are available from the National Water Information System Web interface (NWISweb). Data are also published in the Annual Data Report (ADR). The ADR is now available online and can be accessed using a text or map interface.

Relevance and Benefits

An important part of the USGS mission is to provide scientific information to manage the water resources of the Nation, and to minimize the loss of life and property from natural disasters. Floods are one of the most widespread and destructive natural hazards. To better understand the locations and risks of flooding, the USGS assesses flooding potential, investigates flood occurrences, and collects streamflow information to define the magnitude and frequency of flooding and the causative meteorological events in a wide variety of environments. From this information, more accurate estimates of flood risk and damage, and planning for structures, especially of highways in Nevada, are possible.  Data are collected during the peak-flow of flood events to define river stage/stream discharge rating curves at streamgaging stations. Where possible, post-flood surveys are made to reconstruct peak discharge values and characteristics using indirect methods. Where possible, flood-inundation areas are obtained at the peak of flow from satellite or aircraft images. The data collected during floods and following floods in Nevada are vital to maintain an effective plan for designing hydraulic structures for highways in Nevada.  

Publications

Annual Data Report: Text || Map

Hess, G.W., and Williams, R.P., 1998, Flood investigations in Nevada--A partnership of the USGS and Nevada Department of Transportation: U.S. Geological Survey Fact Sheet FS-039-98, 2 p.

Hess, G.W., and Glancy, P.A., 2000, Flood characteristics of the Wassuk Range Near Hawthorne, Nevada: U.S. Geological Survey Fact Sheet 100-00, 2 p.

Crompton, E.J., Hess, G.W., and Williams, R.P., 2002, Estimated flood flows in the Lake Tahoe Basin, California and Nevada: U.S. Geological Survey Fact Sheet FS-035-02, 2 p.