PRRIP Adaptive Management Plan - Laserfiche WebLink

Home Browse Search

a. sand augmentation through mechanical actions- island and bank clearing and leveling, b. sand augmentation from bank and island actions not directly related to bank cutting and island leveling (an example could be excavation associated with wetland development), or c. reducing the imbalance through channel plan form changes, tributary delivery improvements, or flow routing changes. 3. Use the EA and other Program water to create annual peaks as large as can be sustained over many years, likely through the creation of annual, short-duration high flows within existing banks. Try to ensure that the spring peak flow is higher than any subsequent summer flow. The focus of this concept is on several overall management objectives for Program lands including: 1) improvement of river channel areas on Program lands toward habitat complex characteristics described in Table 1 of the Land Plan (increased availability of areas of wide, shallow channel with unobstructed view and sandbars suitable for roosting and nesting); 2) maintain those improvements; and, 3) minimize or offset current river processes that tend to diminish channel areas on Program lands approximating Land Plan Table 1 characteristics. This approach would prioritize Program land acquisition upstream of Minden, Nebraska, with an objective of acquiring roughly 6,400 acres upstream of this location, and the remaining 2,800 acres downstream. By prioritizing upstream sites, overall Program habitat benefits could be maximized. The over-arching hypothesis associated with the Flow-Sediment-Mechanical approach, as indicated by the physical processes CEMs in Section III, is that a combination of flow management, sediment management, and l and management implemented concurrently will generate detectable changes in the channel morphology of the Platte River, and habitats for whooping crane, least tern, piping plover, pallid sturgeon and other species of concern. In turn, creating the habitat conditions described in Land Plan Table 1 will increase least tern and piping plover production from riverine habitats, and increase survival of migrating whooping cranes. Species benefits may be gained by implementing one or two of the individual management actions of the Flow-Sediment-Mechanical approach, however more substantial benefits can be realized by applying these actions in tandem (e.g., when sediment is added to the river without mechanical actions, the habitat benefits may not be detectible within the First Increment of the Program; flow increases without sediment augmentation could result in negative effects). Meaningful tests of the Flow-Sediment-Mechanical approach will be compromised without implementing all three actions in concert. Following is a discussion of each of the three actions. IV.B.l.a. Mechanical Management Action: To increase the acreage of channel area greater than 750 feet wide by 30 percent over the 1998 baseline conditions for the study area, and restore channel habitat toward Land Plan Table 1 characteristics. The following methods and others where appropriate and effective will be used: September 1, 2006 Adaptive Management Plan 22