Walking down to Bullneck Creek at Chesterwood Park in Dundalk, Baltimore County Environmental Protection and Sustainability Director David Lykens pointed out one of the county’s dozens of man-made wetlands. This one protects 450 feet of shoreline, about the length of one and a half football fields.
“Some of them are thousands of feet long,” Lykens said. “We have them all sizes, all styles throughout the county.”
For decades, Baltimore County has spent tens of millions to create marshes to fight erosion and pollution. Now that climate change is threatening shorelines, officials will be watching to see if that investment will offer protection or eventually be inundated by rising waters.
More than 4,200 tons of sand were trucked in and 8,000 wetland grasses were planted to create the Chesterwood Park marsh last spring at a cost of $708,000.
David Riter, the supervisor of the county’s waterway restoration program, said a barrier made of stones protects part of the marsh during storms.
“If we didn’t have a structure in front of the sand, it would wash into the water,” Riter said.
Over the last 30 years, the county has done more than 40 shoreline projects at a cost of around $21 million. During that time, they’ve seen an uptick in intense storms, according to Rob Ryan, the county’s watershed restoration manager.
“Related to like tropical storms and wind and wave energy along the shoreline which is creating more erosion along the tidal waterways of Baltimore County,” Ryan said.
Wetlands act like a giant sponge, absorbing water then releasing it slowly.
Rising sea levels caused by climate change were not part of the equation when environmentalists began building marshes in the 90s according to Alice Besterman, an assistant professor in the department of biological sciences at Towson University.
“That has much more clearly emerged as a stressor for coastal wetlands within the last 10, 15 years,” Besterman said.
Marshes could be threatened by rising sea levels according to Besterman, although she added coastal wetlands can survive because they naturally increase their elevation.
“However, there is a limit to the rate they can do that,” Besterman said. “So if sea level begins rising, or accelerating really, faster than the marsh can keep up, you do start to see effects.”