Benefits of an advanced quantitative precipitation information system

Abstract

Abstract A reconnaissance‐level regional resource accounting approach was applied to quantify benefits associated with an advanced quantitative precipitation information (AQPI) system being developed for the San Francisco Bay area. The AQPI system would provide incrementally higher resolution monitoring of rainfall events and longer lead‐time forecasts compared to current practice. AQPI system costs were estimated to have initial costs of $66 M and $3.3 M annual operation and maintenance; these translate to a present value cost (at 10 years and 6%) of $90 M. Benefits were associated with avoided flood damages, increasing water supplies, and enhancement of ecological, recreational, and transportation services. Total incremental benefits are estimated to be $61 M/year. Taken by category about 48% of the benefits are for flood damage mitigation ($29 M/year), with water supply (32%, $19.5 M/year), ecosystem (3.3%, $2 M/year), recreation (7.6%, $4.6 M/year), and transportation (9.5%, $5.8 M/year). These translate to a present value benefit of $449 M which computes to a base‐level B/C ratio of 5 to 1. Sensitivity analysis indicates a range of B/C up to 10 and down to 2. Given that most of the benefits are dependent on appropriate actions by hazards and water management agencies and citizens, then the AQPI project development involves outreach and training to maximize responses.

Keywords

• benefit–cost analysis
• damage mitigation
• flood forecasting
• water supply