POLICY BRIEF FEBRUARY 2020

UNC JORDAN LAKE STUDY FINAL REPORT

Lead Faculty Researcher: Mike Piehler, UNC Institute for the Environment, University of at Chapel Hill

BACKGROUND Jordan Lake is a man-made reservoir located west of Raleigh and south of Durham in Chatham County. The lake provides drinking water for hundreds of thousands of Triangle residents, recreation for visitors, aquatic habitat and critical control for the region downstream. Jordan Lake has been designated as impaired due to excess nutrient pollution, which can lead to harmful algal growth. The Jordan Lake watershed is divided into two main sections: the section, which includes the cities of Greensboro and Burlington; and the section, which includes portions of Chapel Hill and Durham.

Map of Jordan Lake watershed with locations of major and minor wastewater treatment plants.

In 2016 the North Carolina General Assembly approved legislation directing the North Carolina Policy Collaboratory to conduct a multi-year study on Jordan Lake and potential water quality strategies within the watershed. Over three years, the Collaboratory coordinated a team of more than two dozen university researchers to undertake scientific data collection and analyses. In the final Jordan Lake report, this scientific data is accompanied by an analysis of financial and policy issues that could assist in improving the water quality of Jordan Lake and throughout the watershed. 1

STUDY OVERVIEW

The individual research projects that comprised the study were designed to help answer the fundamental guiding questions of the study:

1. What are the sources of nutrients impacting the water quality in Jordan Lake? 2. What are the nutrient management options and how cost-effective are these options?

An important component of the study was quantitative modeling of both the Jordan watershed and the reservoir itself. The three models provide new information about how Jordan Lake would respond to specific nutrient reduction scenarios.

Topography map (left) and satellite image (right) of the Jordan Lake area. Contour interval is 10 m.

Research projects also included data collection and analysis in regards to: • Paying for nutrient reduction and management • Policy principles and possibilities for the Jordan Lake watershed • Water quality monitoring and water circulation in Jordan Lake • Evaluation of controls of algal blooms • Stream monitoring and nutrient loading • Sediment dynamics 2

• Stormwater control measures • Agriculture in the Jordan Lake watershed • Stakeholder engagement in the Jordan Lake watershed

The results of the modeling and other research projects support and inform management recommendations for Jordan Lake and the entire Jordan Lake watershed.

POLICY RECOMMENDATIONS Recommendations for the Jordan Lake reservoir and watershed fall into three broad categories: • Increasing revenues for management interventions and enhanced water quality • Strengthening local government collaboration around Jordan Lake management • Addressing nutrient loading to Jordan Lake

Some of the specific recommendations detailed in the report are outlined below.

Water Allocation Fee The study recommended that a water allocation fee be implemented for jurisdictions that withdraw water from Jordan Lake as a new revenue strategy. A fee of 5 cents per 1,000 gallons of water would generate about $2 million annually for water quality projects throughout the entire watershed. This additional fee will ensure that beneficiaries of the lake join upstream communities in the watershed in maintaining a healthy lake. Given the high cost of some non-point water quality measures, it becomes even more important to find ways of spreading costs among as large a population as possible, including users of the lake outside the watershed.

Nutrient Recycling A multi-faceted, long-term strategy is needed to address nutrient loading in Jordan Lake. All recommendations must take into consideration the internal storage of nitrogen and phosphorous in reservoir sediments and its potential impact on algal growth. Reservoir modelling by researchers at NC State University found that even a 50% reduction in external nutrient loads is expected to reduce historical chlorophyll a levels by only about 6% in 1 year. After 20 years, mean chlorophyll a will be reduced by about 15% and after 40 years by 21%. Thus, it will take the lake decades to fully respond to nutrient loading reductions and achieve a new steady state.

Land Conservation Land conservation programs offer a promising strategy for reducing nutrient loading in the lake. Watershed modelling found that undeveloped lands export 10 times less nitrogen and phosphorous than agricultural and urban lands per unit area. As such, development of natural lands will substantially increase nutrient loading to Jordan Lake. The Jordan Lake Watershed Conservation Strategy drafted by the Triangle Land Conservancy and modeled after the successful Upper Neuse Clean Water Initiative could be a powerful tool for protecting water quality.

FUTURE ACTION Upon receipt of the UNC Jordan Lake Study Final Report the North Carolina Department of Environmental Quality is charged with initiating a new regulatory process for the development of the Jordan Lake Nutrient Management Strategies.

Ultimately, management strategies must be adaptive to take stakeholder input into account and allow course corrections. In addition, continuous monitoring of the lake as part of an ongoing effort to maximize local water quality is essential for ensuring that management of the lake is not implemented in a static manner as new information becomes available.

A complete list of the policy recommendations can be found in the full Jordan Lake Report found at: https://collaboratory.unc.edu/files/2020/01/2019-jordan-lake-final-report.pdf 3