Local river facing stress
Speaker concerned about development
By DAN PARSONS
The Tar-Pamlico River watershed is not as bad off as other rivers in North Carolina, but may soon feel the full force of pollutants caused by development, Tar-Pamlico River Foundation Executive Director David Emmerling said Wednesday.
With a persistent drought and the onset of a warming climate trend, protecting the future of the river falls to every locality along its 2,500 stream miles, he said, during a “State of the River” presentation at the N.C. Estuarium.
The river has an advantage over its neighbors, like the Neuse — the entirety of which is considered impaired — because its upper reaches are not developed to the extent that the Neuse’s are. But development in Beaufort County and upstream may soon take its toll, especially since runoff from construction sites is the largest source of harmful sedimentation.
Protecting the river’s future falls to a 16-county area. About 420,000 people share the Tar-Pamlico River watershed with 500,000 hogs. That region is short 14 inches of rainfall for the year, according to Emmerling. It would take between 18 and 25 inches of rainfall within the watershed to end the drought, he said.
The coastal areas through which the river flows are not immune to the effects of drought, he said. In recent months the amount of water flowing downstream has been lower than ever recorded. That means there’s less water to dilute the waste products humans and animals pump back into the river. During the week of Sept. 28 to Oct. 5, 2007 the river reached an all-time low flow, Emmerling said. During that period, the ratio of treated sewage to river flow was the highest it had ever been, he said.
That had little effect on the safety of Beaufort County’s drinking water, which is drawn from the Castle Hayne aquifer. The aquifer runs from New Jersey to down around Wilmington, which means it recharges quickly and has a robust flow. But, Emmerling said even the Castle Hayne may not be immune to the effects of climate change and drought and the state of the aquifer has little to do with the water levels in the river, which is fueled by groundwater.
Replenishing groundwater levels is an slow process, Emmerling said. If the area were to experience 50 inches of rainfall in one year, only one inch of that goes to replenishing the groundwater, he said. The rest flows away as runoff or is retained in contained bodies of surface waters such as lakes and ponds, he said.
Recent rains have helped ease drought conditions across swaths of the state, including eastern counties. As of this month, the drought in eastern North Carolina was “likely to improve” and its “impacts ease” in eastern counties, according to the National Oceanic and Atmospheric Administration. Emmerling said the state’s expected growth may flow into the state faster than available water resources.
Water demand in North Carolina is projected to grow 36 percent over the next 20 years, he said. That will require about $17 billion in additional public works to provide water and sewer services to residents, he said. Meeting the water demand of a larger population in the future will require controls to be implemented now, he said.
Emmerling said there is a “critical need” for watershed-wide stormwater rules, as recently proposed by the N.C. Division of Water Quality. The science behind climate change predicts storms will occur less frequently but with a greater intensity — meaning more water hitting the ground in a shorter period of time, he said.
The new rules call for lower thresholds of development before stormwater controls are triggered, something that Emmerling said was a “necessity” for the future health of the river. Those rules are aimed at lessening the amount of fecal coliform bacteria that runs into the state’s waterways, from their headwaters to the coast. The bacteria, which comes mostly from animal waste and failing septic systems, is linked directly with water closures to fishing and recreation in coastal counties. Since the bacteria cannot live for more than two days outside the gut of an animal and an average river speed of 1 to 2 mph, Emmerling said bacterial pollution is a “local issue.”