CHAPEL HILL — Exceptional June rainfall stressed local creeks, reopening doubts some local residents have about the wisdom of paving paths along waterways.
Runoff water bit a large chunk out of the newly-paved bike path between Estes Drive and Wilson Park in Carrboro. Swollen streams were believed to have overtopped a trail bridge crossing elsewhere on Bolin Creek.
“As Chapel Hill continues to develop, we have a higher percentage of land that’s impervious, whether it’s a rooftop, street, parking lot or something else,” said John Morris, a former waterways manager. “That means when rain falls, it’s going to run off much faster and produce a higher flood peak.”
A former director of the Division of Water Resources at the N.C. Department of Environment and Natural Resources, Morris said growth in Chapel Hill has increased the force and volume of stormwater reaching creeks.
This can have all sorts of drawbacks. Rapid runoff erodes soil and vegetation, carries pollutants downstream and does not get filtered through absorption into soil and root systems.
June flooding, another consequence of rapid and uncontained stormwater, pushed people out of their homes and led to a disaster declaration.
“When we get that much rain in that intensity over such a short period of time, it’s a big stress,” said Randy Dodd, environmental director with the Carrboro Planning Department. “We have a lot of development in this town that occurred prior to some of the regulations and some of the understanding that has come into place.”
Linda Haac, a founder of the Save Bolin Creek website and a monthly columnist for the Chapel Hill News, said flooding and erosion on the greenways illustrated some reasons why some local environmentalists objected to paving near creeks, and the clearing of trees and brush.
“It was something that went on for a couple of years in the Greenways Commission,” said Haac, who sits on Carrboro’s transportation advisory board. “It was very, very acrimonious.”
However, rapid runoff, not a swollen creek, damaged the multi-use path between Estes Drive Extension and Wilson Park. The conduit lets bikers avoid the tight shoulder where Estes climbs a hill to connect with North Greensboro Street and “wasn’t controversial at all, because it was seen to benefit bikers and not harm the environment,” Planning Director Trish McGuire said.
Still, paving over earth can be detrimental, said former Town Council member Julie McClintock, a member of the Chapel Hill Stormwater Advisory Board and the Friends of Bolin Creek.
“Any time water can go through soil, it gets cleaned,” she said. “The longer it can go through woods, and the slower it flows, the better quality it will be when it reaches the end.”
Carrboro estimates it will cost $350,00 to build the Morgan Creek Trail. New links in the Bolin Creek Trail will cost upwards of $630,000. The town has not awarded construction contracts for either section.
As for the washed-out path between Estes Drive and Wilson Park, work crews have since restored it.
McGuire estimated the work would cost between $3,000 and $5,000, and Carrboro might be able to tap into emergency state funds to pay for it.
Carrboro has two segments of greenway slated for development, one along Morgan Creek and the other connecting the Winmore neighborhood to Chapel Hill High.
Both of Carrboro’s proposed greenways are in the design phase.