Auxiliary Spillways
|
| Learn more about the importance of spillway design criteria at DamFailures.org |
“An auxiliary spillway is infrequently used and may be a secondary spillway (augmenting a service spillway discharge capacity). During operation there could be some degree of structural damage or erosion to the auxiliary spillway due to releases up to and including the maximum design discharge. Auxiliary spillways may be less robust, erosion-resistant structures consisting of some cast-in-place reinforced concrete, riprap channel protection and/or unarmored excavated channels”.[1]
In the past, auxiliary spillways were commonly referred to as " emergency spillways". This practice should be discontinued. Media references to flow through “emergency spillways” often leads to a misconception by the public that an emergency condition exists at a dam when the dam is safely functioning as designed. [2]
Life Cycle of Auxiliary Spillways
Examples
Learn more about the importance of spillway design criteria at DamFailures.org
Best Practices Resources
Technical Release 210-60: Earth Dams and Reservoirs, NRCS, 2019
National Engineering Handbook: Chapter 21 - Design Hydrographs, NRCS, 2019
National Engineering Handbook: Chapter 50 - Earth Spillway Design, NRCS, 2014
Selecting and Accommodating Inflow Design Floods for Dams (FEMA P-94), FEMA, 2013
Hydraulic Design of Spillways (EM 1110-2-1603), USACE, 1992
Design of Small Dams, USBR, 1987
Trainings
On-Demand Webinar: Introduction to Addressing Inadequate Conveyance Capacity at Dams
On-Demand Webinar: Inspection and Assessment of Spillways
On-Demand Webinar: Inlet and Outlet Hydraulics for Spillways and Outlet Structures
Citations:
Revision ID: 5524
Revision Date: 12/14/2022