The State of Missouri has developed a sound program for dam safety including existing dams, construction of new dams, and maintenance of dams. Potential earthquake shaking effects are applied to the construction of new dams and to other dams if there appear to be demonstrable safety hazards as outlined by State statutes.
The regulations relative to seismicity are based on a 1980 understanding of potential seismic effects. While there have not been major changes in the knowledge concerning the types of dams regulated by the State of Missouri since that period, there are new concepts that should be reviewed. For example, the 1980 probabilistic analysis that addressed seismic loading may not be current, given the existence of several new studies, such as risk-based ground motion mapping by the U.S. Geological Survey. Also, earthquake-induced deformations rather than accelerations could be more appropriately used relative to dam design in designated areas. Also, changes may be needed relative to the downstream environment as it pertains to public safety.
The review should be accomplished by a panel of specialists. This panel should include persons who are very familiar with the Missouri Statute that addresses dam safety and the spirit of that statute, such as a representative of the Dam and Reservoir Safety Council and a program staff member. Other panelists should be included: a seismologist having knowledge of earthquake activities and potential effects in the Midwest; and a geotechnical engineer with a background in the seismic effects on dam foundations. Seismic provisions of the rules will apply to new dams.