PROJECT ALERT NOTICE (SD) DWSC Flooding

Date: Thu, 21 Mar 2019 15:36:07 EDT

Summary: USGS response to flooding in SD (Day 8).

Flooding is occurring in the southern half of SD with 11 gages at major flood stage, 9 gages at moderate flood stage, and 6 gages at minor flood stage. River basins impacted by flooding include Split Rock Creek, the Big Sioux, Vermillion, Skunk, and James Rivers in the east. Moving westward the Bad, White, and Cheyenne Rivers have stations above flood stage. High flows into Angostura Dam in the SW corner of SD are resulting in significant releases from the dam.

https://waterwatch.usgs.gov/?id=wwsa&site_no=06401500

The White River near the border with NE was near POR this morning.

https://waterwatch.usgs.gov/?id=wwsa&site_no=06445685

The area around Sioux Falls, SD is still forecasted to have near or above POR conditions by early to the middle of next week as is the James River nr Scotland. Forecasts and possible impacts are documented in this new report:

https://www.argusleader.com/story/news/crime/2019/03/21/south-dakota-flooding-james-big-sioux-river-national-weather-service/3231940002/

USGS crews have been busy making discharge measurements, collecting HWMs, and ensuring seasonal gages are ready for runoff. Crews have made 21 measurements this week with efforts to measure efficiently being hindered by ice/debris flow in the channel and extensive overland flooding. Ratings for 3 locations on the Big Sioux and 3 locations on the White River have been extended for the MBRFC. Many streamgages are still not displaying discharge to the public due to this ice.

The DWSC has been in contact with the Office of Communications and media outreach is planned. Stakeholders are being informed of our activities through updates to NWISWeb and NWSChat.