Safe operation of aging dam infrastructure requires regular updates to design flood estimates and spillway operating rules. This paper presents a semi-automated methodology for updating design floods for return periods of 10 to 10,000 years, utilizing a suite of open-source software tools. The framework was applied to the El Caracol, Infiernillo, and Villita dams within the Balsas River hydroelectric system in Mexico. The methodology is based on the Engineering Institute of National Autonomous University of Mexico (IIUNAM) procedure, incorporating frequency analysis of daily mean flows and the generation of design hydrographs using the AX and IIHIDRODIS programs. Flood routing was subsequently performed under various operational policies using the Trate, HEC-HMS, and Traven programs to develop safe and effective strategies. Key recommendations include: for El Caracol dam, a staggered discharge policy for floods exceeding a 50-year return period (Tr); for Infiernillo dam, limiting discharges to 6000 m3/s during frequent floods (Tr < 100 years) and up to 12,000 m3/s for extreme events; and for La Villita dam, operating at 6000 m3/s, potentially increasing to 10,000 m3/s under extreme conditions while respecting downstream channel capacity. The proposed sequential automation markedly reduces processing times, in particular during the sequence involved in constructing a design flood. Previously, this task required approximately one or two days; it can now be completed in just a few minutes, demonstrating a significant advancement in the state of knowledge for studies on dam safety reassessment.
Arganis et al. (Sat,) studied this question.