New NOAA Precipitation Frequency Estimates for South Dakota Now Available

(The direct link to the updated NOAA precipitation frequency estimates for South Dakota is

Interests in private industry, government and academia have eagerly awaited the publication new precipitation frequency estimates for South Dakota as well as sixteen other midwestern and southeastern states. Those estimates were published by the NWS Office of Hydrologic Development on April 19th as Volumes 8 and 9 of NOAA Atlas 14, a web based publication available at . The last time that these estimates were updated was in 1963.

Precipitation frequency estimates are estimates of climate variability. They are used as design standards for civil infrastructure built to cope with rainfall and runoff such as storm water drainage systems, roads, bridges, culverts, small dams, roofs, airport runways, in-stream ecosystems including fish habitat, stream erosion control, pollution control systems, flood insurance rate maps, soil conservation, etc. These new estimates directly contribute to the preparation of more cost effective designs, plans, maps, etc.; protecting lives and property and preventing pollution.

NWS precipitation frequency estimates--prepared since the 1950s--are cited as design standards in many Federal, State and Local Government regulations. These new NOAA Atlas 14 Volumes will result in new design criteria for a large range of engineering and planning projects across most states. Several states have been updated and are indicated by the blue shading in Figure 1 below.

Figure 1.  Map showing the states where the newly updated NOAA precipitation frequency estimates are available. For more information see .

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