Putting a value on green infrastructure to protect coastal communities

Global climate change is increasing the threats of storms and sea-level rise to coastal communities. Coastal managers have traditionally relied on “gray” infrastructure such as seawalls, jetties, and floodgates to protect communities against erosion and property damage, but these artificial structures have been criticized for damaging natural ecosystems. As a result, coastal cities such as New York and Boston—as well as many smaller coastal communities—are considering investing in “green” infrastructure to enhance their resilience to coastal hazards.

Green infrastructure creates or maintains a “living shoreline” that can include wetlands, oyster reefs, barrier islands, and ecologically enhanced bulkheads and revetments. If green infrastructure is well-integrated into a larger upland-to-wetland landscape, it can provide important habitat for plants and animals. Although coastal managers generally recognize the potential ecosystem benefits of living shorelines, green infrastructure options are rarely integrated into investment assessments, because site-specific ecosystem valuation can be very costly and time consuming.

WHOI Marine Policy Center researchers Di Jin, Hauke Kite-Powell, and Porter Hoagland, have developed a methodology to evaluate the benefits associated with living shorelines by quantifying the economic value of ecosystem services provided by green infrastructure. The team examined coastal protection designs at several sites in East Boston and on Cape Cod and found that green infrastructure is economically justifiable in many areas, particularly those subject to low-to-moderate wave energy.

WHOI’s ecosystem valuation methodology has already been used in two major policy analyses: the evaluation of the proposed Boston barrier and a cost-benefit analysis of the Boston Harbor Cleanup. By giving coastal managers a new tool to assess the economic value of the ecosystem services associated with living shorelines, this new methodology should facilitate the wider inclusion of green infrastructure in climate adaptation planning and coastal protection, to the benefit of coastal communities and the environment.