Plans for a flood plain

The Red River Valley can protect itself from a 500-year flood event, at a cost of about $4 billion.

That investment would buy about $12 billion in protection, essentially the estimated damage from a 500-year flood event, according to a two-year study called "Red River Basin Long Term Flood Solutions" which the Red River Basin Commission recently completed.

The RRBC study outlines a path to reducing basin peak flood flows in the basin by 20 percent. Engineers have determined that the devastating Grand Forks-East Grand Forks flood of 1997 could have been prevented, had flows been reduced by 20 percent.

To reach that level, the RRBC recommends a combination of measures, from the Fargo-Moorhead diversion project, to developing upstream water storage during peak flood periods and development of local infrastructure to achieve 500-year protection.

The RRBC will present its recommendations to the Minnesota Legislature in January, and to the North Dakota Legislature when it convenes again in 2013.

"This is a roadmap to put us in a more resilient position, where we're able to fight larger and larger floods with little or no damages," said Lance Yohe, RRBC executive director. "This is what you need to think about for the future. That's the message we want to give to the state legislatures. Maybe we can do it faster by getting federal dollars."

Turning plans into action

It'll take time, perhaps as long as 50 years. But many agencies, as well as cities and other governments throughout the Red River Basin, already are working toward the goal.

One relatively new organization, the Red River Retention Authority, is likely to play a major role. Organized in 2009, it is comprised of Red River Joint Water Resource District on the North Dakota side of the river and the Red River Watershed Management Board on the Minnesota side.

The RRRA's primary objective is to pursue and ensure joint, comprehensive and strategic coordination of water retention projects, along with facilitating the construction of water retention in the valley. As a part of its mission, it is being asked to pursue federal funding to offset local costs for retention projects and to serve as an advocate for local projects in the federal regulatory process.

"We've got to be proactive, rather than reactive," Yohe said.

Key components of the RRBC study's recommendations are:

- Addressing critical needs/risks, including the Fargo-Moorhead metropolitan area and Devils Lake.

The RRBC recommends building the planned $1.77 billion Fargo-Moorhead diversion. The U.S. Army Corps of Engineers estimates damage basin damages from a 500-year flood at $9 billion to $10 billion.

According to the study, immediate measures are needed to mitigate a potential natural overflow of Devils Lake to the Sheyenne River, and a comprehensive model with real-time data should be developed to determine the effects of releases of Devils Lake water to the Sheyenne and Red River basins.

- Flood plain management.

Local flood plain ordinances should be developed to prohibit new development in high-risk areas adjacent to the mainstem Red River and its tributaries.

It also recommends levels of protection be raised in an integrated approach to protect urban areas, critical infrastructure, small cities, rural residences, farmsteads, cropland, critical transportation and emergency services.

Basin-wide water retention strategies should be developed, including upstream water storage during peak flood periods.

The plan calls for a variety of measures to achieve that 20 percent flow reduction during periods of flooding.

Among the upstream storage possibilities are dams, such as the 60,000 acre-feet held back by the Maple River Dam in southeast North Dakota, or development of storage for some 140,000 acre-feet of water through projects by the Red River Watershed Management Board in Minnesota.

Ring dikes already have been built to protect cities, such as Perley and Georgetown, Minn., as well as farmsteads and critical infrastructure on both sides of the Red. More of that should be done, too, according to the report.

"We're not saying one way of holding water is better than another," Yohe said. "The idea is to reduce flows at certain points through any of those means. You have to analyze them, and determine what can be done locally."

The study indicates that just two -- Halstad and Oslo, Minn. -- of the 18 cities studied in the basin already meet or exceed the RRBC's recommended guidelines for 200-year protection, based on current and planned levels of protection and upstream storage. (See accompanying chart).

If all of the RRBC's recommendations would be implemented, Grand Forks-East Grand Forks' flood protection, currently rated at a 250-year flood, would be raised to 500 years.

Wahpeton-Breckenridge and Fargo-Moorhead would be close, according to Yohe. Officials currently are studying ways to achieve the added protection.

Other areas that would reach the RRBC recommended protection goals are Georgetown, Perley and St. Vincent, Minn.

However, two communities -- Drayton and Pembina, N.D., -- would need to implement additional flood-protection measures, according to Yohe.

In Drayton, for example, an oxbow in the Red River has been eroding the banks of the river downtown, which prevents the construction of a permanent dike. Therefore, temporary dikes are built along Main Street during most floods.

In Pembina, permanent flood protection is complicated by conditions along the Pembina River, which flows into the Red in the city along the U.S.-Canadian border. Engineers and local officials still need to address those issues, according to Yohe.

"This is a plan to look ahead, to make ourselves much more resilient to flooding," Yohe said. "There's work to do. But we can achieve this. It's doable."

Reach Bonham at (701) 780-1110; (800) 477-6572, ext. 110; or send email to kbonham@gfherald.com .