USGS Surface Water Information
New & Noteworthy
Today's Water Conditions
View maps of current and historical conditionsStreamflow
Flood and high flow
Surface water quality
USGS in Your State
USGS Water Science Centers are located in each state.
Other Water Sites
Documents are presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.
Selected USGS Surface-Water Programs & Activities
A powerful new tool for flood response and mitigation are digital geospatial flood-inundation maps that show flood water extent and depth on the land surface.
The USGS operates and maintains approximately 7,500 streamgages which provide long-term, accurate, and unbiased information on streamflow to meet the needs of many diverse users.
The NSS Program is a desktop computer program that replaces the National Flood Frequency Program (NFF) to provide simple methods of estimating streamflow statistics for ungaged sites that are needed for planning, regulatory, and design purposes. The NSS program contains regression equations for estimating peak-flow and low-flow magnitudes and frequencies, flow-duration discharges, and other statistics. User input of the basin characteristics used as explanatory variables in the equations is required to obtain the flow estimates. Equations for estimating peak-flow statistics are available nationally. Availability of equations for estimating other statistics varies by State.
StreamStats is a Web-based Geographic Information System (GIS) that provides users with access to an assortment of analytical tools that are useful for water-resources planning and management, and for engineering design applications, such as the design of bridges.
The USGS has been involved in developing and using acoustic flow measurement technology since the late 1960s to improve the accuracy of an efficiency of streamflow measurements.
What is Climate Change? The USGS strives to understand how the earth works and to anticipate changes in how the earth functions. To accomplish this, USGS science aims to understand the interrelationships among earth surface processes, ecological systems, and human activities. This includes understanding current changes in the context of pre-historic and recent earth processes, distinguishing between natural and human-influenced changes, and recognizing ecological and physical responses to changes in climate.
The USGS developed a mobile storm-surge network to capture information of the timing, extent, and magnitude of storm tide.
Modeling of watershed response to normal and extreme climatic conditions or to changes in the physical conditions of a watershed requires the simulation of a variety of complex hydrologic processes and process interactions.