Jordan Lake is one of the Triangle Area’s principal reservoirs. Its 14,000 acres of water serve as drinking water supply for approximately 460,000 people. Originally constructed by the Army Corps of Engineers in 1981-82 for flood control, the reservoir now serves as drinking water supply, recreational site, and wildlife habitat. In 2008, 32% of Jordan Lake’s annual allocation went to Cary and Apex, doubling from its 1997 allocation. In 2008, allocations also went to Chatham County (6%), the city of Durham (10%), and OWASA (5%), with lesser percentages to Holly Springs, Morrisville, Orange County, and Wake County- RTP.
Water Quality Concerns
Soon after the lake’s impoundment in 1982, it was declared a Nutrient Sensitive Water (NSW) by the Environmental Management Commission (see Technical Notes). Nutrients from wastewater, runoff from agriculture, and stormwater run-off have led to an increase in green algae growth especially during the summer months, and the formation of potentially toxic algae. By 2002, the Division of Water Quality found that the Upper New Hope Creek arm of the lake was impaired due to high levels of chlorophyll a, a primary indicator of drinking water quality. In 2006, the rest of the lake was listed as impaired. (see Technical Notes).
The federal Clean Water Act (CWA) requires that states address waters which have been listed as impaired and to develop Total Maximum Daily Loads (TMDLs) which specify how nutrients or pollutants will be reduced. In 2007, a Total Maximum Daily Load was approved by the EPA for Jordan Lake. Rules specifying how the lake would receive a reduction in nutrients were originally approved by the Environmental Management Commission in May of 2008, but then amended in 2009 because of complaints that local governments would be required to install costly stormwater prevention measures. The amended Jordan Lake Rules call for a reduction in phosphorus and nitrogen for each the three arms of the reservoir, however they don't allow the Environmental Management Commission to require of local governments that they retrofit existing developments with stormwater retention measures.
Pollution from development, run-off, stormwater and other sources affect New Hope Creek, the Haw River, Morgan Creek, and Little Creek, which in turn flow into Jordan Lake. Since New Hope Creek and the Haw River, the two primary inflow rivers to the reservoir, contribute different amounts of phosphorus and nitrogen to the lake, each arm of the lake is required to reduce nitrogen and phosphorus levels to different degrees. The amounts of nitrogen and phosphorus that must be reduced according to the Jordan Lake Rules, therefore, differ depending on whether it is the Upper New Hope, Lower New Hope, or Haw River arms of the lake:
Figure 1: Nutrient Reduction Goals for Jordan Lake. Goals are expressed in terms of a percentage reduction from the baseline years (1997 – 2001)
Author Brunell Gugelmann, North Carolina State University :: 2010 April 27 Reviewers Tom Davis, Water Resources Coordinator, Orange County :: Amy Pickle, Duke University Technical Notes Nutrient Sensitive Water (NSW) is classified as any body of water that is in need of additional nutrient management due to it being subject to the excessive growth of microscopic or macroscopic vegetation. Environmental Management Commission is a 19-member Commission appointed by the Governor, the Senate Pro Tempore and the Speaker of the House. The Commission is responsible for adopting rules for the protection, preservation and enhancement of the State's air and water resources. Commission members are chosen to represent various interests, including the medical profession, agriculture, engineering, fish and wildlife, groundwater, air and water pollution control, municipal or county government, and the public at large. The Commission oversees and adopts rules for several divisions of the Department of Environment and Natural Resources, including the Divisions of Air Quality, Land Resources, Water Quality, and Water Resources. Total Maximum Daily Load , or TMDL, is a calculation of the maximum amount of a pollutant that a waterbody can receive and still safely meet water quality standards. Impaired Body of Water : a body of water which fails to meet state water quality standards for its designated use as, for example, a recreational site or public drinking water supply.
Water Indicators
Fresh Water Supply :: Water Use
Water Pollution :: Miles of Impaired Streams :: Riparian Buffers :: Major Dischargers :: Groundwater
Case Studies :: Jordan Lake Rules :: Falls Lake Rules
Case Study: Jordan Lake Rules
photo source: http://www.ncparks.gov/Visit/parks/jord/main.php
Water Quality Concerns
Soon after the lake’s impoundment in 1982, it was declared a Nutrient Sensitive Water (NSW) by the Environmental Management Commission (see Technical Notes). Nutrients from wastewater, runoff from agriculture, and stormwater run-off have led to an increase in green algae growth especially during the summer months, and the formation of potentially toxic algae. By 2002, the Division of Water Quality found that the Upper New Hope Creek arm of the lake was impaired due to high levels of chlorophyll a, a primary indicator of drinking water quality. In 2006, the rest of the lake was listed as impaired. (see Technical Notes).
The federal Clean Water Act (CWA) requires that states address waters which have been listed as impaired and to develop Total Maximum Daily Loads (TMDLs) which specify how nutrients or pollutants will be reduced. In 2007, a Total Maximum Daily Load was approved by the EPA for Jordan Lake. Rules specifying how the lake would receive a reduction in nutrients were originally approved by the Environmental Management Commission in May of 2008, but then amended in 2009 because of complaints that local governments would be required to install costly stormwater prevention measures. The amended Jordan Lake Rules call for a reduction in phosphorus and nitrogen for each the three arms of the reservoir, however they don't allow the Environmental Management Commission to require of local governments that they retrofit existing developments with stormwater retention measures.
Pollution from development, run-off, stormwater and other sources affect New Hope Creek, the Haw River, Morgan Creek, and Little Creek, which in turn flow into Jordan Lake. Since New Hope Creek and the Haw River, the two primary inflow rivers to the reservoir, contribute different amounts of phosphorus and nitrogen to the lake, each arm of the lake is required to reduce nitrogen and phosphorus levels to different degrees. The amounts of nitrogen and phosphorus that must be reduced according to the Jordan Lake Rules, therefore, differ depending on whether it is the Upper New Hope, Lower New Hope, or Haw River arms of the lake:
Figure 1: Nutrient Reduction Goals for Jordan Lake. Goals are expressed in terms of a percentage reduction from the baseline years (1997 – 2001)
Author Brunell Gugelmann, North Carolina State University :: 2010 April 27
Reviewers Tom Davis, Water Resources Coordinator, Orange County :: Amy Pickle, Duke University
Technical Notes
Nutrient Sensitive Water (NSW) is classified as any body of water that is in need of additional nutrient management due to it being subject to the excessive growth of microscopic or macroscopic vegetation.
Environmental Management Commission is a 19-member Commission appointed by the Governor, the Senate Pro Tempore and the Speaker of the House. The Commission is responsible for adopting rules for the protection, preservation and enhancement of the State's air and water resources. Commission members are chosen to represent various interests, including the medical profession, agriculture, engineering, fish and wildlife, groundwater, air and water pollution control, municipal or county government, and the public at large. The Commission oversees and adopts rules for several divisions of the Department of Environment and Natural Resources, including the Divisions of Air Quality, Land Resources, Water Quality, and Water Resources.
Total Maximum Daily Load , or TMDL, is a calculation of the maximum amount of a pollutant that a waterbody can receive and still safely meet water quality standards.
Impaired Body of Water : a body of water which fails to meet state water quality standards for its designated use as, for example, a recreational site or public drinking water supply.
Data on water allocations for Jordan Lake were taken from a PowerPoint presentation given by Toya Ogallo, of the Division of Water Resources on February 24, 2010: Jordan Lake Water Supply Allocation Process Round 4Information on nitrogen and phosphorus reduction goals was obtained from the Jordan Reservoir Nutrient Management Strategy and Total Maximum Daily Load Public Review Draft (April 2005)
Additional information on the Jordan Lake Rules was obtained from http://www.thetimesnews.com/news/signs-26284-governor-jordan.html)
Water Indicators
Fresh Water Supply :: Water Use
Water Pollution :: Miles of Impaired Streams :: Riparian Buffers :: Major Dischargers :: Groundwater
Case Studies :: Jordan Lake Rules :: Falls Lake Rules