National Weather Service United States Department of Commerce

Effective February 13, 2019, the National Weather Service (NWS) in Rapid City, SD will change the flood category stages for the Cheyenne River near Wasta (WASS2) and the Cheyenne River near Plainview (PLNS2).

All NWS flood warnings, flood statements, flood advisories, flood watches, probability outlooks, and NWS hydrographs on the Advanced Hydrologic Prediction Service (AHPS) will reference the new category levels. This change is part of a recent evaluation of the levels based on high water, flood events, and impacts over the past 10 years.

Graphic showing Cheyenne River near Wasta flood category changes   Graphic showing new flood levels for Cheyenne River near Plainview

Cheyenne River near Wasta


New Flood Levels

Action Stage: 11 ft
Flood Stage: 13 ft
Moderate Flood Stage: 15 ft
Major Flood Stage: 16 ft

Previous Flood Categories

Action Stage: 11 ft
Flood Stage: 14 ft
Moderate Flood Stage: 16 ft
Major Flood Stage: 17 ft


Cheyenne River near Plainview


New Flood Levels

Action Stage: 15 ft
Flood Stage: 17 ft
Moderate Flood Stage: 19 ft
Major Flood Stage: 20 ft

Previous Flood Categories

Action Stage: 14 ft
Flood Stage: 16 ft
Moderate Flood Stage: 17 ft
Major Flood Stage: 19 ft


The National Weather Service welcomes public feedback. If you have any questions or comments on this change, please contact:

Melissa Smith
Service Hydrologist
(605) 341-9271 ext 493

National Weather Service
300 East Signal Drive
Rapid City SD 57701