Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 7/19/2010
Publication Date: 6/1/2010
Citation: Benik, R., Cooper, C., Hunt, S.L. 2010. Hydraulic jump stilling basins. In: Benik, R., et al., editors. Outlet Works Energy Dissipators, Chapter 2, FEMA Technical Manual P-679. CDROM. Interpretive Summary:
Technical Abstract: An outlet works is a combination of structures and equipment required for the safe operation and control of water released from a reservoir to serve various purposes like regulating stream flow and water quality; releasing floodwater; and/or providing irrigation, municipal, or industrial water. Outlet works may include an intake structure, conduit, control house-gates, regulating gate or valve, gate chamber, and/or an energy dissipation structure. An energy dissipation structure slows the velocity and dissipates the energy of the flow released from an outlet works. A hydraulic jump dissipates energy in water flowing through an outlet works and prevents scour downstream. A hydraulic jump stilling basin is a structure used to locate, create, and contain a hydraulic jump from a variety of flow conditions. A hydraulic jump occurs when supercritical flow on a steep slope changes to a mild slope such that the flow goes from a critical to subcritical state. This chapter discusses the development of a hydraulic jump and the dimensioning and design of the stilling basin necessary to contain the energy dissipated by the hydraulic jump. Design elements of stilling basins discussed include chute blocks, end sills, cutoff walls, training walls, flow deflectors, and underdrains. This chapter also provides great detail in design criteria for stilling basins developed by the USBR, USACE, and the USDA-ARS.