Cost-effective private dam safety assurance policy and spillway design/review

A case study was conducted in the policy-absent state of South Australia where 11 hazardous private reservoirs were investigated for spillway adequacy in line with state-of-the-art practice. Common high levels of deficiency were discovered. Extended flood studies of hypothetical dams placed on the same catchments were also conducted. Appropriate analysis led to the derivation of regionalized relationships based on simple hydrological/hydraulic variables, for predicting reservoir flood capability as either 1/AEP or %PMF. The relationships were employed to develop a simple and cost-effective flood capability design/review procedure for reservoirs on small catchments.