New parameter codes will not be available on NWISWeb
Data for new parameter codes (released after June 2026) will only be available through Water Data for the Nation services. Data currently available through legacy NWISWeb applications will not be affected.
We have announced that the remaining NWISWeb legacy pages will be decommissioned between October 2026 and February 2027, and that WaterServices will be decommissioned in early 2027. As part of preparing for these decommissions, we are no longer implementing new functionality on legacy NWISWeb or WaterServices systems.
In particular, the USGS is regularly expanding its list of parameter codes used to describe a constituent being measured and its unit of measurement. Data for new parameter codes (using any code released after June 2026) will not be available through legacy NWISWeb pages or the WaterServices APIs. Data currently published via the legacy system will continue to be available until those services are decommissioned in the coming months.
Data using new parameter codes will be made available through Water Data for the Nation (WDFN), the modernized home for USGS water data, as well as through the Water Data APIs. These modernized applications provide a centralized home for all of the USGS water data collections and provide access to all the data available via legacy NWISWeb pages.
We encourage users to migrate to Water Data for the Nation pages and the WDFN APIs before the legacy systems are decommissioned in Winter 2027. Please reach out to us wdfn@usgs.gov with any questions or feedback you may have.
Categories:
Related Posts
Modernized access for USGS rating curves is now available
August 14, 2026
Modernized access for USGS rating curves is now available
The USGS publishes rating curves describing the relationship between stage and streamflow at a monitoring location. Historically, these curves have been published at the NWISWeb Ratings Depot, available at https://waterdata.usgs.gov/nwisweb/get_ratings.
Peak Measurements in WDFN
August 14, 2026
There has been a lot of change to how you access USGS water data as we work to modernize data delivery in WDFN and decommission NWISWeb. As we centralize data delivery in WDFN, we have described different types of water data according to data collection categories. We re-organized and expanded the data collection categories that are delivered on the Monitoring Location Page and are now working to deliver additional data collection categories on WDFN. This blog is part of a series to help orient you to where you can find different types of data in WDFN pages and services. In this post, we focus on how you can access peak measurements in WDFN.
How we work on the Water Data for the Nation Team
March 9, 2021
The USGS Water Mission Area (WMA) is the largest provider of real time and historical water information in the world. A major part of our work in the WMA Web Communications Branch is to build modern web applications and APIs to make these data publicly available. We call our data delivery product line Water Data for the Nation (WDFN). Here’s our product vision:
The Observations API will be decommissioned October 19, 2026
October 2, 2026
The experimental Observations API (hosted at
labs.waterdata.usgs.gov/api/observations/) was a service hosted on thelabs.waterdata.usgs.govdomain, providing lists of related monitoring locations and subsets of data from the National Water Information System. After an evaluation period, we’ve decided that we will not be promoting this service to production status and will instead be decommissioning the service.Announcing V1 of the WDFN APIs
September 4, 2026
Public USGS Webinar: NWISWeb Decommissioning Campaign 3
NWISWeb launched real-time data pages in 1995 and has hosted more than 7 million annual unique visitors, billions of successful page requests, and terabytes of data delivered. After several years of modernization, we are beginning the final decommissioning or turning off of legacy NWISWeb webpages. This means that pages that you may have relied on for years are going away.
This webinar will share information on NWISWeb Decommission Campaign 3, which will retire all remaining NWISWeb pages and WaterServices. Campaign 3 is expected to be ongoing from November 2026 through February 2027.