Objective: 

The area surrounding the confluence of the north and south branches of Thornton Creek (Seattle) experiences storm water-related flooding more often than other areas. A cost-benefit analysis, which incorporated ecosystem services values, aimed at identifying the best cost-benefit ratio among three possible options. The assessment results were intended to inform the decision of the choice of a project option.

Lessons learned: 

The project influenced the assessment of policy options. The detailed monetary assessment supported the decision of the implementation of project options that balance the economic, environmental, and social benefits.