Date of this Version
Five instream flow methods were applied to a variety of streams within the state of Nebraska. These were (1) the Tennant method, (2) a modification of the Tennant method, (3) IFG1 A, a single cross-section average-parameter method, (4) the Incremental method, using the WSP hydraulic simulation program, and (5) the Incremental method, using the IFG4 hydraulic simulation program.
Each method was applied following standard published procedures, and instream flow recommendations were developed for the streams addressed using each method separately. Evaluation of the methods showed that the modification of the Tennant method overcame some of the deficiencies of the Tennant method and appears to be most useful for Nebraskan reconnaissance-grade studies. Where instream flow issues might be resolved through negotiation, or where they involve valuable fishery resources, the Incremental method might be justified. An investigator, using the WSP program for unstable bed streams and the IFG4 program for stable bed streams, can assess the effects of altered flow regimes on stream fisheries. Although requiring a greater time and financial commitment, the Incremental method can be used to provide the information needed for responsibly resolving conflicts.