Floodplain management issues related to the performance of dams in Georgia during tropical storm Alberto

As part of the Federal Emergency Management Agency's (FEMA's) response to flooding in the Flint River and Ocmulgee River basins during July 1994, FEMA formed a Dam Performance Assessment Team (DPAT) as a technical resource to support the Interagency Hazard Mitigation Team (IHMT). The DPAT's primary objective was to develop an understanding of the causes behind the failure of over 200 dams during Tropical Storm Alberto. This information along with recommendations from the DPAT, was then used by the IHMT to develop specific recommendations to mitigate the flood hazards related to dam performace in Georgia. The DPAT identified a number of floodplain management issues related to the performance of dams in Georgia during Tropical Storm Alberto. Many of these issues have applicability outside of Georgia and should be considered by state and local floodplain managers when managing their programs. Dam safety and floodplain management issues are intimately related. As evidenced by the flooding in Georgia, dam failures for storms near the 100-year level can increase flood hazards

A new method to estimate earthquake liquefaction damage to buried lifelines

A new method that relates soil movement to buried lifeline damage state has been developed and applied during a Federal Emergency Management Agency-sponsored study to evaluate the impacts of lifeline proximity during earthquakes. The method considers landslides and liquefaction as a continum of ground displacement; it uses similar analysis methods for estimating the impacts of such motions on buried lifelines. For landslides, a critical acceleration parameter is used to estimate the lifeline damage state, which is also related to a displacement scaling parameter. Similary, a Liquefaction Severity Index (LSI) parameter is used to estimate the lifeline damage state for lateral spread or liquefactions conditions. The LSI can also be related to a displacement scaling parameter. The relationship of the LSI parameter to the earthquake intensity and lifeline damage state is new and is based on empirical data and expert judgement.(AU)