US Army Corps of Engineers
Portland District Website

The water management mission

Detroit reflection--a historical photo

The Corps plays a major role in a coordinated and complex system to reduce flood risks and provide water for hydropower generation, fish and wildlife enhancement, navigation, recreation and other uses. Portland District's primary water management mission is to save lives and reduce property damage by reducing flood risks with measures both structural (such as dams and levees) and non-structural (such as improving the natural function of floodplains). We also assist communities in developing responses to flood risks and hazards.

As part of this mission, we own and operate 16 dams in Oregon, maintaining these dams with available resources to meet authorized purposes, the foremost of which is public safety. We also assess levees for integrity and viability. No combination of actions can prevent floods and no single agency can manage them.

Forecasts, reality and teacups

It remains impossible to accurately predict where and when flooding will occur because it is not possible to accurately forecast the weather more than a few days ahead. The amount of rain and variations in temperature over just a few days, for example, can strongly influence the timing and extent of runoff.  A combination of weather conditions, including heavy snow and unexpected warm rain, contributed to the historic floods of 1964 and 1996.

The Corps uses both short-term (10-day) and long-term (3-month) runoff forecasts to help determine the amount of space needed in its flood storage reservoirs to reduce flood risks. Year-round, the Corps uses the short-term forecast, produced by the National Weather Service Northwest River Forecast Center, to make the timeliest decisions possible.

The National Weather Service Northwest River Forecast Center is responsible for issuing official flood warnings and forecasts. The public is encouraged to visit their website for information about rising river levels. The Corps uses information on this site to help estimate river flows. Check out:

Reservoir teacup diagrams

Visit river basin “teacup” diagrams for real-time reservoir levels. Each project’s smaller “teacup” includes observed inflow, precipitation levels and its specific rule curve. The diagrams also show releases from dams for the past seven and 30 days:


Using the diagrams

Rolling your cursor over a dam symbol brings up a box with the current elevation of the water in the dam's reservoir, how that elevation relates to what is called for in the Water Control Diagram, and the amount of water flowing into and out of the reservoir.

Clicking on the dam symbol brings up more detailed water elevation and flow information, including how water levels relate to boat ramp elevations.

The large "cup" to the left (on the Willamette and Rogue diagrams) explains how close that system as a whole is to its Water Control Diagram.

The Corps of Engineers and other agencies collaborate on gathering and analyzing data regarding current and projected future reservoir and river level information.

This information is hosted on the Northwestern Division Water Management site.

In just a few minutes, this video highlights several key missions we perform on a daily basis in support of the Nation's economy, environment and quality of life: