The Army Corps of Engineers and the U.S. Fish and Wildlife Service announced today that they have come to agreement on a water management plan for the Missouri River reservoirs for the late spring and summer of 2003.
The plan complies with the requirements of the Endangered Species Act while reinforcing the reliability of the system of reservoirs to meet the multiple congressionally authorized project purposes.
Of particular concern are two migratory birds, the endangered interior least tern and the threatened piping plover, listed for protection under the Endangered Species Act. Their nests, found on low-lying, barren sandbars, can be threatened by rising river levels.
The endangered pallid sturgeon was also addressed. Restoration of shallow water habitat and population augmentation efforts continue. The long-term needs of the pallid sturgeon will be addressed in the upcoming discussions on the Master Water Control Manual.
The Service and the Corps agreed to a plan that, when compared to the 30,000 cubic feet per second "steady flow" presented in the 2003 annual operating plan, meets downstream needs while minimizing loss of habitat and impacts to listed species and drawndown of the three biggest reservoirs. The agreement is a combination of "steady flow" features from the final AOP and elements of a "flow-to-target" plan.
It takes advantage of the likelihood of effective downstream tributary flows during the early part of the nesting season through an initial steady release rate. These tributary flows will allow for lower releases from the dams during the nesting season. If runoff conditions permit, those releases will be maintained throughout the nesting season. If downstream flow targets cannot be met at that rate, releases will be increased in order to meet them.
The plan is to set a release rate of 26,000 cfs to 27,000 cfs from Gavins Point Dam, near Yankton, S.D., when the birds initiate nesting. This normally occurs during the period May 8-20. Further increases throughout the summer may be necessary to support downstream flow targets as tributary contributions to the Missouri dry up.
Additionally, use of three Kansas River Corps reservoirs that are authorized to provide Missouri River flow support will be used if appropriate. They could provide additional water to meet the Kansas City flow target, which may reduce the releases needed from Gavins Point Dam, thus limiting impacts to the birds. However, there is currently insufficient water in the Kansas reservoirs to provide Missouri River flow support. Minimization measures are in place to reduce the impacts to the birds if higher releases from Gavins Point are required. These include moving nests, to the extent possible, to higher elevations on the sandbars if they are threatened with inundation.
This plan differs from an actual "flow-to-target" operation because releases will not be decreased during the nesting season. Decreases can threaten nesting birds by encouraging them to nest on sandbars that are likely to be flooded if higher flows are necessary later in the nesting season to meet downstream targets.
The Corps and the Service also discussed whether tern and plover eggs and chicks threatened by inundation from navigation flows would be moved off the river into the Corps
