Technology Merit: Climate Change Risk Modeling and Assessment


CH2M for providing program management for the Miami-Dade County Water and Sewer Department's $3.3 billion Ocean Outfall Legislation Program. The 11-year program with 28 capital projects is the culmination of a regulatory mandate by the Florida Legislature to stop all wastewater discharge to the ocean by 2025.

This task included assessment of projected changes for key climate variables (sea level rise, precipitation, and wind); modeling the extent of inundation due to sea level rise, storm surge, and extreme rainfall for a range of scenarios based on the service life of wastewater facilities; evaluating risks to those facilities from the different climate change scenarios; and estimating the associated costs of protecting facilities.

Using its analyses of costs versus risk, CH2M facilitated a series of workshops with Miami WASD staff and design consultants to select design criteria that specifies flood control elevations and facility hardening options. These were documented in a Design Guide for Hardening Wastewater Facilities against Flooding from Surge, Sea Level Rise, and Extreme Rainfall. These measures are now being used by all of WASD's consultants, and they will undergo revision and enhancement as lessons are learned from each design effort.