The primary objective of this research is to develop and implement a robust multi-criteria decision support framework to enable the North Carolina Department of Transportation (NCDOT) to strategically leverage remnant properties as nature-based solutions for regulatory credit under the Department’s statewide NPDES stormwater permit (NCS000250) and under state nutrient management strategy rules. In recent years NCDOT has experienced a significant escalation in construction costs, including costs associated with designing and constructing stormwater control measures along existing highways as is required by Section 3.6.1 of the NPDES stormwater permit and 15A NCAC 02B .0281 (9)(d) of the Falls Lake nutrient management strategy rules. In an effort to control construction and long-term maintenance costs, NCDOT piloted a project to retain ownership of four adjacent remnant parcels in Division 5 (Falls Lake watershed) and quantify the stormwater management benefits of maintaining the parcels in an undeveloped land cover. The NC Department of Environmental Quality formally recognizes land conservation as a creditable compliance practice and NCDOT demonstrated that the pilot project saved the Department $3,500,000 in avoided design, construction, and long-term maintenance costs of stormwater infrastructure relative to the value of the properties if sold on the open market. The success of the pilot project in Division 5 has demonstrated that remnant properties from right-of-way acquisitions provide a unique opportunity to provide a value-added repurposing of underutilized assets. The aim of this framework is to align NCDOT's stormwater management compliance obligations with the untapped potential of remnant properties by achieving regulatory compliance, environmental sustainability, cost-effectiveness, social impact, and asset optimization through the strategic deployment of nature-based solutions (NBS).
To achieve this objective, the research begins with a systematic literature review, identifying best practices and relevant frameworks in stormwater management and NBS. We will then conduct expert interviews and surveys to engage NBS experts and practitioners. Next, we will conduct outreach activities to engage NCDOT stakeholders, ensuring their valuable input is incorporated into the decision-making process. Then we will collate the knowledge gained in these tasks to develop an adaptable, data-driven decision support framework. Lastly, we will use the newly developed framework to conduct real-world case studies that will test the framework's efficacy, including sensitivity analysis to ensure robustness and flexibility. By combining scientific rigor, expert input, stakeholder engagement, and practical application, the research approach aims to produce a tool bridges the gap between sustainability and effective stormwater management.
This research holds significant importance for both NCDOT and the broader community. It positions NCDOT as a leader in sustainable stormwater management, leveraging remnant properties to reduce costs, enhance environmental stewardship, engage communities, and meet regulatory obligations. Anticipated outcomes include a versatile decision support tool that can be adapted for various scenarios, insights from case studies that provide real-world applicability, and sensitivity analysis results to ensure the framework's robustness. Ultimately, the research empowers NCDOT to make informed decisions that benefit economic efficiency, ecological health, and social well-being in the realm of stormwater management, setting a precedent for sustainable practices in transportation agencies.
