Measuring the Economic Value of Nutrient Assimilation in the Upper Neuse

Private land trusts and public agencies, such as NC Division of Parks and Recreation and NC Wildlife Resources Commission, have traditionally measured their work in “bucks and acres.” Both the public demand for targeted investments in conservation and emerging markets for nitrogen and phosphorus offsets are pushing conservation land managers to measure the ecosystem services for both new and existing projects. By quantifying these benefits, land managers hope to increase the perceived value of conservation land and the services they provide.

The Upper Neuse River Basin, which supplies a majority of the potable water required by the Raleigh-Durham Triangle region, is the focal point of this report. In addition to the competing water consumption demands of the area, such as agriculture, industrial, and landscaping, the water supply is being stressed by nutrient loading. Excessive nutrient loading can disrupt the ecological balance in a watershed, reducing water quality, increasing algae blooms, degrading the aesthetic value of water bodies, and threatening fish and wildlife. Impaired waters are also more difficult to treat, increasing costs for water treatment plants downstream.

It has been established that vegetated riparian buffers can help keep water supplies clean by filtering out surface and subsurface pollution. However, development pressures have led to an undervaluing of this ecosystem service. By 2030, the region’s population is expected to nearly double, with an additional 51,000 acres of open space and rural land lost to development. In the face of these development pressures, conservation groups and land managers are challenged with making an economic case for conservation. This report and the recommendation it generates are intended to provide a “way forward” to land managers and land trust organizations seeking to economically quantify the nutrient assimilation services provided by conservation land.