In 2024, the federal government updated the Principles, Requirements, and Guidelines for Federal Investments in Water Resources to require agencies to maximize public benefits—including non-market ecosystem services—with appropriate consideration of costs. By including ecosystem services in benefit-cost analyses, our understanding of management alternatives improves, helping us to selected strategies that deliver broad benefits to society while still accomplishing conventional project goals.

Last year, Earth Economics supported Bluewing Civil Consulting, Headway Environmental, and the Vermilion Soil and Water Conservation District with an analysis of ecosystem services values under alternatives for development of water control structures and levee systems in the Lower Vermillion Watershed, Louisiana.

 

“Earth Economics brought an entirely new assessment framework to our team.  Their methods and reporting not only satisfied the NRCS’ PR&G requirements, but also educated our team on the growing field of ecosystem services and valuation.  I’m eager at the opportunity to work with them again in the future.”

—Alex Guillory, Bluewing Civil Consulting 

 

A series of levees protect the Hebert Canal, separating intermediate marsh along Vermilion Bay from agricultural lands in the north. Without action, flooding and saltwater intrusion from storm surges and abnormal high tide events will continue to encroach inland, threatening the site’s limited freshwater. Because intermediate marsh vegetation may not be able to spread in areas with higher salinities, intermediate marsh may eventually shift to brackish marsh, or even open water.

Three approaches were proposed to manage storm surge and reduce saline intrusion: Business-as-Usual (No Action), a system of levees and water control systems to protect the full 12,610 acres (Full Protection), and protecting the 6,255 acres of agricultural land, but not the 6,335 acres of marsh (Partial Protection):

Scenario 1: No Action

Scenario 2: Full Protection

Scenario 3: Partial Protection

Earth Economics estimated the value of ecosystem services produced under each scenario, as well as disruption of habitats during construction. We found the second scenario (Full Protection) was the only cost-efficient approach, with a lifetime benefit-cost ratio of 1.61—providing $6 million in avoided crop losses. For context, the third scenario had a benefit-cost ratio of just 0.27, owing to ongoing land cover disturbance over the next 50 years.