News2019 Flood


Record-setting runoff expected for river, two years in a row

Gavins Point Dam.jpg
Posted at 1:53 PM, Jun 05, 2019
and last updated 2019-06-05 16:21:47-04

OMAHA, Neb. (KMTV) — Flooding has pummeled the Midwest and communities along the Missouri River this year. In 2018, runoff in the upper-Missouri River basin, North of Sioux City, was at the third-highest level in recorded history says the United States Army Corps of Engineers (USACE). In 2019, they're forecasting another record-setting year.

The USACE says the top-three years for the Missouri River upper-basin runoff are:

  1. 2011 - 61 million acre feet
  2. 1997 - 49 million acre feet
  3. 2018 - 42.1 million acre feet

The records go back 121 years.

This year they're projecting 50 million acre feet. During May alone, they say 8.9 million acre feet were recorded which is 267% of the normal average.

South of Sioux City, the National Weather Service of Omaha says Missouri River levels are also on course to set records.

In 2011, the year that set a an upper Missouri River basin record, some cities they looked at were at flood stage for more than five months. This year, they say we could see those records broken with flood stage status possible until this fall.

You can read more in the USACE's full release:

Much-above average runoff in the upper Missouri River basin (above Sioux City, Iowa) extended into May following widespread and heavy rainfall in South Dakota and Nebraska. Additionally, widespread and heavy rainfall in the lower basin, particularly in Kansas, has led to large tributary and Missouri River flows downstream of the six main stem reservoirs on the Missouri River.

May runoff in the upper basin was 8.9 million acre feet (MAF), which is 267 percent of average. The average May runoff is 5.6 MAF. May runoff was the second highest on record, only surpassed by 2011's 9.2 MAF. Runoff in the Fort Randall Dam to Gavins Point Dam reach was 1.4 MAF, which is more than the average annual runoff for that reach.

The high May runoff increased the 2019 upper basin runoff forecast to 50.0 million acre-feet (MAF). If realized, this runoff total would be the second highest runoff in 121 years of record-keeping, only surpassed by 2011 (61.0 MAF) and exceeding the 49.0 MAF observed in 1997. Runoff in 2018 was 42.1 MAF, which is currently third highest.