Date: Wed, 18 Jun 2014 09:24:51 EDT
Summary: Extreme flooding in southeastern SD as the result of heavy rains June 14-16
Most of the high flow in the Sioux Falls area has peaked but runoff from the June-14-16 event has resulted in extreme high flows on the lower Big Sioux in South Dakota and Iowa and Rock River in MN. Split Rock Ck peaked June 17 at near 13,000 cfs; Rock River in MN reached a peak of 62,500 cfs on June `17 and is currently still above 55,000 cfs. Rock River joins the Big Sioux upstream of Akron IA where the current stage is 25.51 ft which is 9 ft over flood stage and the highest peak on record.
Three field crews are measuring flows in southeastern SD to document high flows and recessions. A measurement at Akron will take place later today. The forecast for the Big Sioux at Akron gage is projected to peak today or tomorrow at at stage of 25.8 ft.
An additional crew is headed to northwestern SD in anticipation of high flows on the Little Missouri and Grand Rivers as the result of 6-7 inches of rainfall last night, June 17.
All measurements are being shared with the NWS, COE, and State and local agencies.