PROJECT ALERT NOTICE (SD) Dakota WSC Flooding

Date: Wed, 29 May 2019 16:31:19 EDT

Summary: USGS responding to continued flooding in most of South Dakota (SD)from rain.

Gage-heights at thirty-seven (37) US Geological Survey streamgages operated by the Dakota WSC in South Dakota (SD) are exceeding National Weather Service (NWS) minor to major flood stages. Eight NWS river forecast sites are at or forecasted to reach major flood stage. The distribution of the thirty-seven sites experiencing flooding can be observed at the WaterWatch link below.

A sequence of two powerful spring storms in the last nine days delivered widespread rain of 3-5 inches with localized areas receiving more than 7 inches as of yesterday. An additional 0.5-1.5 inches of rain fell over a wide area today but the next few days look to be drier for much of SD. The most significant impacts are occurring on the creeks draining the Black Hills, an area around the Lower Brule Reservation southeast of Pierre, and in eastern SD parts of the James, Vermillion, and Big Sioux Rivers are returning to major flood stage.

All available data section staff in the Rapid City, Pierre, and Huron Offices are in the field today. Additional staff from the Bismarck Office have traveled to SD to assist. Crews are actively documenting high water marks, making discharge measurements, and repairing damaged gages. USGS crews in the Dakota WSC have made 34 measurements in SD since May 21. Field crews are having difficulty accessing some sites due to poor road conditions and are being forced to hike in with their measuring equipment. One streamgage was damaged when floodwaters submerged the gage house. As of today, only one site is not operational. Ratings are being extended or in need of extension at ten sites. One indirect is planned this week with the potential for more. Peak of record conditions are occurring at some sites with shorter records.

The Dakota WSC Facebook page has also been updated with recent flood information: https://www.facebook.com/USGSDakotas/

USGS photos from the field are added daily to (DOI access only) https://drive.google.com/drive/folders/1hTpHM1UwTSVQ4Fvf1N9uFr1modpQrzd0?usp=sharing

Dakota WSC Flood Map