AN UPDATED ANALYSIS OF PRIORITY LANDS FOR CONSERVATION IN THE ELLERBE CREEK WATERSHED

Abstract

Traditionally, conservation organizations sought to protect the most pristine land from the pressures of conversion and degradation. The conserved lands were identified by their inherent ecological value such as biodiversity or their proximity to bodies of water. The legacy of protecting important ecological areas often overlooked natural spaces in urban areas because they were near developed areas or were themselves developed and required restoration. The contrast between urban and rural land protection led to more conservation outside urban areas and made the spaces and ecosystem services even more difficult to access. Our client, the Ellerbe Creek Watershed Association (ECWA), is a Durham nonprofit organization looking to contend with the conservation of natural spaces in an urban area in a more equitable way. Founded in 1999, ECWA was born from the realization that invasive species were proliferating in Durham. Through the use of conservation easements, fee simple acquisition, and transfers ECWA now owns and manages 450 acres of conserved lands. They work to protect and improve the Ellerbe Creek with the help of volunteers, and they are working to expand their efforts with equity and environmental justice at the forefront. ECWA first partnered with The Nicholas School to prioritize conservation lands in 2012. Yacobson (2013) constructed ECWA’s first geospatial tool to identify target areas, and our project works to update and reconstruct the model with both ecological and equity perspectives. Following a multi-criteria decision analysis framework, we constructed an adjustable model that will allow ECWA to find the most opportune areas for conservation according to their needs. Additionally, we emphasized equity as a core component of the analysis. Like many land trusts, ECWA has limited time and resources to devote to geospatial expertise. A driving goal for the project was to create a usable tool for ECWA’s limited GIS infrastructure. We created an easy-to-access, standardized, and easy-to-update model that includes datasets that are reliably funded and managed. Additionally, we synchronized our data with regional conservation efforts and built on established research in the Durham area. In collaboration with ECWA, we decided to base the prioritization on four main themes: (1) Water quality, (2) Habitat, (3) Equity, and (4) Accessibility potential. We combined the criteria from each theme in both equally weighted and adjusted weighting scenarios, resulting in different parcel conservation score rankings. Overall, the prioritization tool fulfills the need for a usable and adjustable tool that identifies the most opportune parcels for conservation. We provide maps and tables of the contributing criteria scores as well as the overall scores for different weighting scenarios. We find that when equity or accessibility are emphasized and weighted more heavily in the model, the resulting parcels with the highest conservation values are in distinctly different locations from model results where water quality or habitat are weighed more heavily. When equity and accessibility are weighed slightly higher than water quality or habitat, the parcels with the highest conservation value are located in more urban areas with lower socioeconomic status. The differences in conservation value based on the weighting scheme reflect how the priorities of a conservation organization can affect which parcels are most sought for conservation. The results can then inform conservation planning, project evaluation, educational outreach, and communication efforts for ECWA as they continue their work to protect the Ellerbe Creek watershed’s quality and provide more equitable access to green space.