Scientific and Procedural Development of Evidence-based Floodplain Crediting Protocol to Meet Water Quality Goals in the Lake Champlain Basin


February 1, 2022 to January 31, 2024


Researchers will characterize floodplains based on their potential functioning to develop, through a partnership with state and local partners, an evidence-based approach for phosphorus crediting of floodplain restoration and conservation, contributing to the goal of improving Lake Champlain water quality and promoting investment in green infrastructure. 

In response to the growing threat of floods and poor water quality in Lake Champlain, the State of Vermont and its partners are working to shift away from heavy-handed floodplain management (e.g., dredging or berm maintenance) towards a greater reliance on the improved capacity of dynamic, naturalized river corridors and floodplains. The State of Vermont, in partnership with consultants and researchers at the University of Vermont (UVM), is currently in the process of establishing the Functioning Floodplain Initiative (FFI). When released in winter 2022, the FFI web application will consist of a set of tools to map and track the status of floodplains and assist in nature-based project planning ( 

To prioritize interventions, these tools will quantify the degree to which proposed projects will restore or preserve the hydrologic connectivity that maintains water quality, flood resiliency, and natural habitats, along with social and economic feasibility factors. Projects will enter a design and implementation phase, which this proposed research will support and then refine prioritization of floodplain reconnection projects, by characterizing the continuum of floodplain types and their variable functioning.

An additional FFI project planning module will be developed to provide estimates of floodplain phosphorus deposition rates for each unit of analysis. Incorporating spatial and temporal variability into project planning and design will improve the State’s estimates of phosphorus load reductions achieved through floodplain reconnection to meet federally mandated clean water goals. 


Rebecca Diehl
Research Assistant Professor, University of Vermont
rebecca.diehl [at]

Resulting Publications

Research Webinar: Tools to Balance Objectives for Restoration and Conservation of Floodplains

Published 2023
In this talk, we introduce decision-support tools for evaluating the multiple, and sometimes incompatible, objectives of different decision-makers for management of floodplains. These tools, developed with Sea Grant support, aim to balance stakeholder objectives and refine the rankings of restoration projects developed under Vermont’s Functioning Floodplain Initiative. Because phosphorus attenuation is a critical objective amongst most stakeholders to meet clean water goals for Lake Champlain, research on the capacity of connected floodplains to capture flood-borne phosphorus is also described. These tools were designed to support a systems-based management approach that best meets multiple stakeholder objectives to promote consensus decision making and cost-effective implementation of nature-based solutions.