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.
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.