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.
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