PROJECT ALERT NOTICE (ND SD) Dakota WSC Flooding

Date: Thu, 04 Apr 2019 14:19:10 EDT

Summary: USGS response to flooding in SD & ND (Day 22).

Gage-heights at thirty-nine (39) U.S. Geological Survey streamgages in South Dakota (SD) and North Dakota (ND) are exceeding National Weather Service (NWS) minor to major flood stages. The distribution of the thirty-nine sites experiencing flooding in the Dakotas can be observed at the WaterWatch link below.

Eastern ND - "Warming temperatures will promote much-increased snowmelt runoff, overland flow, and ice jam flooding thru the end of the week," per NWS in Grand Forks, ND today. The James River in ND is still mostly ice covered but has reached minor flood stage south of I-94. In the Red River Basin river levels are still on the rise north of Wapheton, ND. USGS crews have been making measurements at gaps in the ice and are finding shifts from 0 to -4.0 ft. The Red River at Fargo, ND is forecasted to crest April 8 (Monday) at major flood stage of about 35 ft. (peak of record is 40.84 ft. in 2009). Uncertainty in the forecast still exists due to ice. Links to data and imagery for the Red River Basin are provided below:

The latest forecasts for stations in the Red River Basin are summarized in this news report https://www.inforum.com/news/weather/998425-2019-Flood-Fight-Latest-river-levels-and-flood-forecasts

USGS installed a webcam at Fargo, ND with real-time imagery available at https://cida.usgs.gov/stormsummary/timelapse/BasicData/DakotaWSC/DWSC/DAK_Red_River_Fargo_timelapse_videos/frame_gallery/

USGS photos from the field are added daily to (DOI access only): https://drive.google.com/drive/folders/1bNiqh_sBAegZgSJQyocSZ2skHDlsJkVf?usp=sharing

Eastern SD - Attention is focused on the confluence of the James and Elm Rivers near Aberdeen, SD. The shallow gradient of the James River in comparison to its tributaries is resulting in backwater and even flow reversals of up to -1800 cfs (see 06471000 or 06473000). Breakout flow from the Elm River into Moccasin Creek was measured at 10 cfs yesterday. Moccasin Creek flows through Aberdeen, SD with the potential for flooded property if significant breakout flow from the Elm were to enter Moccasin Creek. A crew will be in the area again today to evaluate if the breakout flow has increased. Seven of nine sites on the James River in SD are at major flood stage with the remaining two at moderate. Crests on the James are currently near Aberdeen, SD and will move downstream over the next week. The James is expected to remain in flood through much of April. In the Big Sioux Basin flows are receding at all stations. Stations near the headwaters are at minor flood stage with the remaining stations at moderate flood stage.

Approximate annual exceedance probabilities (AEP) will be provided for various basins once the peaks have passed.

Since the beginning of flood conditions on March 13, 2019, USGS crews in the DWSC have made 309 measurements despite ice and overland flooding challenges. High stages in the shallow gradient James and Red Rivers is resulting in extensive submerged floodplains with road overflow. The seven of eight RDGs deployed in eastern ND are operational. All data section staff in both states are deployed today to measure flows and repair gages. Seven real-time sites are currently having operational issues. Many bubbler lines have been damaged by ice, but non-contact auxiliary sensors are operational at most. Crews are actively documenting high water marks. Two water-quality samples were collected this week with one more planned for tomorrow.

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

Stakeholders are being informed of our activities through updates to NWISWeb, NWSChat, email, and phone calls.


Dakota WSC Flood Map
USGS Red River Stations