"To ensure Reclamation dams do not present unacceptable risk to people, property, and the environment."
Under its Dam Safety Program, the Bureau of Reclamation (Reclamation) regularly monitors, examines and evaluates the performance of dams in its inventory to ensure facilities do not present unreasonable risks to the public, property, or the environment. Issues are evaluated in terms of loading conditions, structural response and the potential consequences of dam failure. Reclamation strives to provide adequate protection from inherent risks. When risks are determined to be unreasonable, corrective actions are formulated and implemented.
Safety of Dams Process
The SOD Process involves a four-phased approach:
- Inspection and Review. A Comprehensive Review (CR) is performed every 8 years and a Periodic Facility Review is performed halfway through the CR cycle so that major reviews are accomplished every 4 years. Annual reviews are performed during the other years. The CR not only examines the dam itself, but also examines other issues over the years, such as construction reports, documentation, and observations -- compared with new information, new technology, and current dam engineering practices.
- Issue Evaluation. This phase involves additional studies, usually stemming from recommendations made during the CR process such as evaluation of foundation deposits for liquefaction, evaluation of structural components to withstand earthquakes, evaluation of new hydrologic information, and changes in the understanding of loading conditions (such as seismic, static, or hydrologic).
- Corrective Action Study. If sufficient justification to reduce or better understand risk is identified during the Issue Evaluation, a Corrective Action Study is initiated. In this phase, various alternatives are explored to reduce risks to an acceptable level. Operational changes and potential modifications are evaluated. Constraints are examined such as environmental, economic, constructability, feasibility and interim operations. Alternatives are developed and investigated to address the problem, and the appropriate alternative is chosen.
- Design/Modification. This phase begins with collection of design data and may include evaluation of materials within the dam, foundation, and/or materials to be imported to be used during construction. It usually also includes survey and photogrammetry. Design of the modification progresses as design data is gathered and includes a value engineering analysis. Once the design and associated specification package are complete, the project is issued for bid. The successful contractor submits proposals to accomplish each phase of the modification. Reclamation oversees the contractor’s construction activities, including testing of materials and assuring that the contractors work meets the specifications. Upon project completion, the dam is returned to the beginning of this cycle (Inspection and Review).
For additional information, please contact CGB Region Safety of Dams or call 916-978-5328.