US Army Corps of Engineers
Northwestern Division Website

Missouri River Water Management

Frequently Asked Questions about the Missouri River System

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Yes. We’ve recently modified our Daily River Bulletin to include additional river stations.

We also link to hourly data for several stations. 

Technical studies are periodically updated to include the most recent information. The report “Runoff Volumes for AOP Studies” was last updated in August 2013 to include runoff data from 1898 to 2011. The Corps will complete a preliminary analysis of the runoff data to see if an update of the report is needed before the draft AOP is prepared in August 2020.

A variety of studies and reports on the operation of the Missouri River Mainstem System are prepared and published regularly.

Statistical information on the operation of the Missouri River Mainstem System is recorded and evaluated by the Missouri River Water Management Division.

Missouri River Location Flood Stage (in feet) Flow at Flood Stage (in cfs)
Sioux City 30.0 125,000
Decatur 35.0 121,000
Omaha 29.0 116,000
Nebraska City 18.0 92,000
Rulo 17.0 90,000
St. Joseph 17.0 100,000
Kansas City 32.0 241,000
Waverly 20.0 117,000
Boonville 21.0 162,000
Hermann 21.0 195,000

The U.S. Army Corps of Engineers (Corps) Missouri River Basin Water Management (MRBWM) office develops runoff volume forecasts for the purpose of meeting downstream flow targets to serve system purposes such as navigation, water supply and flood control.

Runoff forecasts for Mainstem System operations use data from the National Weather Service’s Missouri Basin River Forecast Center and Climate Prediction Center, the U.S. Geological Survey, the Natural Resources Conservation Service, State climate offices, and others.

Short-Range Runoff (Inflow) Projections: Day-to-day scheduling of releases is necessary to regulate the System on an integrated basis and requires the Corps to develop daily flow forecasts at key streamgaging locations throughout the basin. These forecasts are based on observed and anticipated precipitation, temperature, temperature-snowmelt relationships, rainfall-runoff relationships, observed streamflow in the main stem of the Missouri River and tributaries, previous precipitation and other factors that often may be subject to only qualitative analysis.

Lower Missouri River Streamflow Forecasting: Scheduling releases from Gavins Point during the open-water season (generally late March through mid-December) is based on downstream navigation target locations on the Missouri River at: Sioux City, IA; Omaha, NE; Nebraska City, NE; and Kansas City, MO. Of these four locations, Omaha, Nebraska City and Kansas City also serve as downstream flood control target locations. The Corps’ Missouri River Basin Water Management office schedules the mainstem project releases, including Gavins Point. Scheduling Gavins Point releases requires developing accurate forecasts of lower Missouri River reach inflows between Gavins Point, the lowermost System dam, and flow forecasts of at the four downstream target locations. These forecasts are developed daily and project 14 days in the future. They are compared to daily forecasts developed by the NWS's Missouri Basin River Forecast Center.

Monthly Reach Inflow (Runoff) Forecasts: The first week of each month, the MRBWM office prepares a monthly incremental inflow forecast for the six System reservoir reaches. These forecasts are based on, but not limited to: monthly average reach runoff, historical reach runoff, existing and previous soil moisture conditions, reach precipitation and/or river gage readings during March-April and May-July, observed reach temperature, accumulated snow over the incremental drainage area, long-term precipitation and temperature outlooks, and accumulated mountain snow water equivalent. Projected runoff calculations includes water in the system, in the soil, in mountain snow, and plains snow estimates and precipitation outlooks from the National Weather Service's Climate Prediction Center.

Short-term forecast precipitation is not included in runoff volume forecasts. When and where precipitation occurs and how it appears in tributaries is imprecise. Forecasting runoff volume without including forecast precipitation is why runoff volume estimates can change significantly.

The National Weather Service Missouri River Basin Forecast Center provides forecasts for rivers and tributaries in the Missouri River Basin.

The Daily River Bulletin is a daily product from the U.S. Army Corps of Engineers Missouri River Basin Water Management office, which includes current stages and flows for various locations throughout the basin.

Each month we update our upper basin runoff forecast and reservoir studies. The Missouri River Mainstem System of dams is operated as a system and release decisions are evaluated system-wide.

Yes, the National Weather Service regularly issues Hydrologic Outlooks. They also share considerable information regarding Flood Safety on their website.

There are two types:
Short-term (1 to 7 days) Hydrologic Outlooks can be issued to alert the public of the potential for flooding in the near-term such as when heavy rainfall is forecast that could result in flooding or aggravate an existing flood if it occurs.

Long-term (weeks to months) Hydrologic Outlooks may also provide river or reservoir level and/or flow information. This information could be used for water supply concerns or projection of snowmelt flooding. In the Missouri Basin, the Spring Hydrologic Outlook is issued in February and March.

A long-range river flood outlook is available on the NWS website and shows locations with a greater than 50% chance of exceeding river flood levels in the next 3 months. The website is interactive and can show flood chance percentages from 5 to 95%.

Hazardous Weather Outlooks and Alerts may also be indicators of potential for flash flooding.

Similarly, drought information is also available for Weekly, Monthly or Seasonal Outlooks.

The Missouri River freezes completely over in the upper basin during the winter, which greatly restricts the amount of water we can release from the Fort Peck, Garrison and Oahe reservoirs. While it appears it would be beneficial to make higher releases during the winter, it is not that simple. During the winter an ice cover forms over the river channel making the river a “pipe”. If we push too much water down the “pipe”, it will burst. When the ice cover forms, the river stage dramatically increases. Once the ice cover forms, we slowly increase releases and smooth out the underside of the “pipe”; thus releasing more water. However, the maximum winter releases are never going to be as high as the releases we can make during open water (non-ice cover) conditions.

Increasing flows on the river does not prevent ice from forming. Reasons for this include sustained outside temperatures below freezing, high wind chills, and water temperatures that will drop below freezing at the water’s surface.

Increasing flows also increases the river stage. The river will still freeze but at a higher stage, which would increase flood risk.

A warmer winter, even in Montana and North Dakota, still means below-freezing temperatures and frozen tributaries and rivers.

Space is reserved in each reservoir to capture and manage runoff during the high runoff months (March-July) which is then emptied during the lower runoff months (August-November). That reserved space is the designated flood storage volume. A volume of 16.3 million acre-feet (MAF) was established based on more than 100 years of hydrometeorogical data and the engineering capacity of the System projects.

The Missouri River Basin Water Management office makes regulation decisions so all 16.3 MAF of the reserved flood control space is available at the start of each runoff season, which is around March 1. The combined flood control space of the six projects totals 16.3 MAF. When we have 16.3 MAF of flood control space available to capture runoff, we are also storing 56.1 MAF of water in the six reservoirs.

If the 16.3 MAF of flood control space were larger, then the releases would be even lower when runoff is lower and releases would be even higher when runoff is higher. This is because the System would still be operated to return to the set amount of available flood control space by March 1.

There are different resources available to you when the river is flooding dependent upon your location.

Local levee sponsors should be contacted regarding interior drainage issues, or water on the "dry side" of the levee. The National Levee Database is the best resource for locating your local levee sponsor.

If you want to take measures to prevent stream bank erosion during a high water event, work with local Regulatory offices to ensure you are in compliance with state and federal laws.

If you represent a Federal, Tribal, State or Local agency you can contact either the Kansas City District Emergency Management Office (for Missouri Basin locations south of Rulo, NE) or the Omaha District Emergency Management Office (for Missouri Basin locations north of Rulo, NE).

The National Weather Service Missouri River Basin Forecast Center shows locations that are currently in minor flood stage or higher.

This NWS MRBFC chart shows river stage observations for locations throughout the Missouri River Basin.

The National Oceanic and Atmospheric Administration monitors the status of El Nino and La Nina providing outlooks each quarter.

Quarterly climate outlooks are published through the National Integrated Drought Information System.

The National Weather Service Climate Prediction Service has compiled several frequently asked questions about El Nino and La Nina.

Each gate has rubber seals around them. There will still typically be some leakage. There are stoplogs that can be placed on the upstream side of the gate that will allow work, such as inspecting or replacing the rubber seal, on a dewatered gate to take place when water is above the spillway elevation.