Background/Objectives

While many utility owners recognize flood risk to their critical infrastructure, it can be challenging to develop and schedule flood mitigation projects. One typical approach, evaluating discrete annual chance flooding events (e.g., 1% or 100-year flood, 10% or 10-year flood), may not provide an accurate or complete understanding of total flood risk. Budget limitations also add an additional complication: risk reduction must be balanced with costs. This process becomes more daunting given the changes in flood risk over time due to climate change. Annualized losses can offer an improved and more complete characterization of flood risk compared to individual events. However, annualized loss calculations are complex and difficult to communicate. This presentation will discuss a strategy to optimize the annualized loss approach that can alleviate many flood mitigation project planning complexities. 

Approach/Activities

The strategy uses multi-objective optimization informed by annualized losses to identify a suite of potential mitigation schedules. Then, it explores the tradeoffs between flood risk reduction (calculated as annualized losses) and budget constraints based on the various schedules produced. The approach considers changes in flood risk over time; they play a key role in indicating which projects should be delayed or expedited. The optimization is fully automated and written in a Python script that is potentially applicable to different kinds of clients and projects.  

Results/Lessons Learned

The optimization results help define an initial capital improvement plan for owners. The plan a) clearly indicates when various buildings should be mitigated and b) outlines funding needs through the planning horizon. Whether utility owners are considering self-funding or applying for grants to complete their mitigation goals, this approach can help them understand and appropriately plan for climate change mitigation.