Chance constrained optimization model using kinematic wave routing for stormwater infrastructure rehabilitation
A chance constrained optimization model is presented to determine efficient long-term replacement strategies for segments of stormwater drainage systems. The model is multiobjective in nature and driven by probabilistic stormwater flow considerations that are determined using kinematic wave equations. Model objectives include: the minimization of total rehabilitation costs and the maximization of stormwater system reliability. Model results stipulate rehabilitation activities for each period in the planning horizon. Rehabilitation alternatives include replacement, upgrade and varying the design capacity of the stormwater system. This provides the decision maker with the ability to consider storing peak flows rather than increasing conveyance capacity. The model can be used to develop trade-off relationships between the minimum rehabilitation cost and the system's probability of failure due to extreme storm events. To illustrate the proposed model, and example using a hypothetical stormwater catchment is presented.
