Technical Manual: Conduits through Embankment Dams (FEMA 484)

Conduits through Embankment Dams• Any other personnel who may be needed, like laborers and the design engineer,and how they are to be contacted. If there is no designer of record, a list of twoto three qualified professional engineers should be available for contact.The EAP should also document the following items as they pertain to coordinationof information and communicating with the emergency response personnel:• The need for coordination of information on flows based on weatherconditions and runoff forecasts and embankment dam failure and otheremergency conditions. Describe how the coordination is achieved and thechain of communications, including names and telephone numbers ofresponsible people.• Additional actions contemplated to respond to an emergency situation orembankment dam failure at an unattended dam.• Actions to be taken to lower the reservoir. Describe when and how (maximumdrawdown rate) this action should be taken. Also, alternative means ofevacuating the reservoir should be specified in the event the outlet works isinoperable, releases through the outlet conduit are not recommended due to ainternal erosion situation, or the outlet capacity has been reduced for somereason.• Actions to be taken to reduce inflow into the reservoir from upstream dams orcontrol structures. The inflows should be stopped or diverted around thereservoir, if possible.• Actions to be taken to reduce downstream flows, such as increasing ordecreasing outflows from downstream dams or control structures on thewaterway on which the embankment dam is located or its tributaries.The EAP should also describe other site-specific or emergency repair actions thatcan be devised to moderate or alleviate the extent of the potential emergency andpossible failure of the embankment dam. The EAP will recommend actions, butserves only as a guide, since there are typically many variables. A trained dam safetyofficial will, in most cases, need to determine the type of action required.Table 11.2 provides a list of potential problems and immediate response oremergency repair actions that can be undertaken. This is a relatively comprehensivelist and includes problems and the associated emergency response as they relate toconduits through embankment dams (FEMA, 1987; Colorado Division ofResources, 2002). Caution is advised in using table 11.2, since many variables areinvolved, and each damsite is different.268