Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

A few weeks ago, on February 14, 2020, the USGS celebrated the 25th anniversary of a historical milestone, the first public delivery of near real-time water information to over the internet. Prior to February 14, 1995, for 100 years virtually all USGS water data was delivered through paper reports or direct requests to USGS offices, was available primarily as daily statistics (e.g. daily mean discharge), and only after extensive data validation and review – usually a year or more after the date of collection. The transition to our current system of robust delivery of almost all instantaneous data in near real-time and on-line access to our entire historical data holdings did not happen overnight. The initial system, then called rt_www, started with only a handful of sites in Montana delivering a few days of recent streamflow data. It took years of IT development and policy and workflow changes to get to where we are today. It is questionable whether the small group of Montana Water Science Center developers of that initial system knew the full power of what they unleashed, but it is now hard to imagine water science and water resources management in the United States without what we now refer to as Water Data for the Nation. Without invalidating any of the historical water data uses and users, it vastly expanded the range of both for the betterment of all.

Screenshot showing one of the earliest pages showing real-time data on the web.

A screenshot of one of the original sites, on Water Data for the Nation, Missouri River near Culbertson MT

A few months ago, on December 18, 2019, another milestone in USGS information delivery was reached that is likely to have similar positive repercussions for both the USGS and the nation in the years ahead - the release of a new water availability mapper. While only a concept prototype, for the first time the USGS is delivering a daily product that integrates our active monitoring with continuous modeling. Just as rt_www started the process of freeing us from data delivery latency, so the release of the new mapper has started the process of freeing us from reporting water information only where we are doing active monitoring. Rather than reporting on a few thousand sites nationally, we can now look to report on 100,000 or more. Just as the release of rt_www expanded historical users and uses without changing them, so the release of new modeled products will only further extend the range of what is possible. As with rt_www, it will take many steps over years to fully realize our plans for more types of data, more informative delivery products, and more robust data access, and there are no doubt good ideas we have not thought of yet, but we’re very excited by the first small step and look forward to the coming efforts.

An animation highlighting different parts of the country uning a map that ranges from dark blue (High natural water storage) to dark brown (Low natural water storage). . November 6th, 2019: Unusually Wet conditions prevail in the upper midwest (Upper Midwest is highlighted and dark blue).  November 12, 2019: Unusually dry conditions conditions throughout California coincide with widespread wildfires (California is light brown).  November 21, 2019: Remmnants of Tropical Storm Raymond usher in unusually wet conditions (The southwest part of the United States is highlighted and dark blue). The animation ends with a USGS Logo and the text National Integrated Water Availability Assessments

The National Integrated Water Availability Assessments concept map compares current natural water storage to daily historical values. This animation shows the effects of a number of different events on natural water storage in November of 2019.