Optimal Design Storm Frequency for Flood Mitigation in the North Valsayn Community of Trinidad

Abstract

Determining the right amount of money or budget to be spent on flood mitigation works has always been a challenge in developing countries. This study investigates two (2) economic approaches that can be used to determine the level of protection or the optimal design storm frequency for flood mitigation works within the North Valsayn community of Trinidad. The economic approaches investigated can be described as (i) the Cost per Inhabitant (CPI) approach and (ii) the Hydroeconomic Analysis (HEA) approach. To facilitate these economic approaches, the following was done: (i) Identify flood hazards using a calibrated 2D hydraulic model, (ii) Assess the community’s vulnerability by developing a Flood Damage curve, (iii) Identify flood mitigation works for various design storm frequencies, and (iv) Determine the life cycle cost for implementing the design various design solutions. Although both methods are acceptably used in the industry, the study shows a disparity in defining a project’s budget and the Optimal Design Storm Frequency that is worth paying attention to by decision and policy makers, government agencies, practicing engineers, project managers and other stakeholders although both are acceptably used in the industry.