Source: https://erdc-library.erdc.dren.mil/jspui/ ; The intake structure of the proposed Dutch Gulch Dam will provide effective regulation of both flood-control and water quality releases. The model investigation of the outlet works for the proposed structure was concerned with verification and improvement of the hydraulic design of the intake structure, conduit, and stilling basin. The study was conducted in a 1:25-scale model of the outlet works, which reproduced a portion of the approach area, the intake structure, the outlet conduit, the hydraulic jump type stilling basin, and approximately 400 ft of exit channel. Pressure flow occurred in the turbine exit chamber for turbine releases greater than 600 cfs. Enlarging the exit chamber portal and streamlining the portal invert should result in greater turbine releases under partial flow conditions. The conduit experienced slug flow for a wide range of flood-control discharges, which created surges in the stilling basin and exit channel. The conduit was vented, resulting in a significant reduction of the range of discharges for which slug flow occurred. Pressures were positive throughout the intake structure for all discharges observed. Performance of the original design exit channel was inadequate, resulting in significantly higher tailwaters than expected. As a result of model tests, changes were made in the design of the exit channel to pass the desired discharges. The stilling basin baffle piers were also modified in accordance with Engineer Manual 1110-2-1602, "Hydraulic Design of Reservoir Outlet Structures." Performance of the type 2 design exit channel and stilling basin provided adequate energy dissipation and flow conditions for all discharges (excluding slug flow) observed.