Keywords

wetlands; flood protection; ecosystem services; decision analysis

Start Date

25-6-2018 3:40 PM

End Date

25-6-2018 5:20 PM

Abstract

Sea level rise exposes economically and ecologically productive assets to tidal and extreme flooding. In California, sea level rise expected by 2100 puts half a million residents, two international airports and other key infrastructure in flood zones created by 100-year storms. Coastal wetlands dissipate tidal storm surges and buffer runoff from rain events, reducing flood risks to nearby properties. Restoring or constructing wetlands can be more cost-effective than use of levees. The value of wetlands relative to artificial structures is enhanced by added ecological and recreational benefits. Prior work has structured the evidence connecting wetland rehabilitation interventions to environmental and ecological impacts into a generalized, qualitative ‘results chain’ model. Here, we examine the case study of the marshlands around Gallinas Creek in Marin County, Calif., where sea level rise expected by 2100 will put 8,000 acres of land and 4,500 properties into flood zones created by a 100-year storm. We derive a system of equations with probabilistically distributed parameters to forecast flood-protection and ecological benefits for alternative management interventions. We model benefits from upland storm water retention, tidal storm surge dissipation and enhanced ecological productivity and recreational value in the community. The economic advantage of wetland restoration relative to development of artificial structures depends on the supply of sediments available to sustain wetland elevation relative to rising sea levels and the area available for wetland development. This tool may be adapted to guide wetland rehabilitation decisions more broadly.

Stream and Session

Stream C: Integrated Social, Economic, Ecological, and Infrastructural Modeling

Session C6: Ecosystem Services Values and Quantification: A Negotiation between Engineers, Economists, and Ecologists

Download
COinS
 
Jun 25th, 3:40 PM Jun 25th, 5:20 PM

Forecasting ecosystem services to guide coastal wetland rehabilitation decisions

Sea level rise exposes economically and ecologically productive assets to tidal and extreme flooding. In California, sea level rise expected by 2100 puts half a million residents, two international airports and other key infrastructure in flood zones created by 100-year storms. Coastal wetlands dissipate tidal storm surges and buffer runoff from rain events, reducing flood risks to nearby properties. Restoring or constructing wetlands can be more cost-effective than use of levees. The value of wetlands relative to artificial structures is enhanced by added ecological and recreational benefits. Prior work has structured the evidence connecting wetland rehabilitation interventions to environmental and ecological impacts into a generalized, qualitative ‘results chain’ model. Here, we examine the case study of the marshlands around Gallinas Creek in Marin County, Calif., where sea level rise expected by 2100 will put 8,000 acres of land and 4,500 properties into flood zones created by a 100-year storm. We derive a system of equations with probabilistically distributed parameters to forecast flood-protection and ecological benefits for alternative management interventions. We model benefits from upland storm water retention, tidal storm surge dissipation and enhanced ecological productivity and recreational value in the community. The economic advantage of wetland restoration relative to development of artificial structures depends on the supply of sediments available to sustain wetland elevation relative to rising sea levels and the area available for wetland development. This tool may be adapted to guide wetland rehabilitation decisions more broadly.