Erosion threatens Falmouth shoreline roads, sewers
FALMOUTH — For many people, rip-rap sounds like the name of a cartoon character or perhaps the newest pop music craze.
But for those living along Shoreline and Bayshore drives, rip-rap could save their property and streets from being swept into the sea during the next big storm.
"The land here is mostly sands and clay, which is highly erodible," said Jonathan Edgerton, a project engineer for Wright-Pierce.
Edgerton presented a study on the erosion issues to the Town Council during last week's meeting. He explained that a combination of wave action, storm drains and seeping groundwater has eroded land in the area, putting public infrastructure such as sewer pipes and roads at risk.
"During storms, we've seen waves crash over the (Mackworth) midway," said Councilor Bonny Rodden, who lives on Shoreline Drive. Rodden has recused herself from the council vote on this issue, but said she is deeply concerned about the erosion along the road. In some areas, the land begins to drop off less than six feet from the road.
Rodden said she and several of her neighbors are worried the erosion could create hazards for school buses and delivery trucks, since no one knows how stable the soil is under the existing road.
While some property owners have cut trees and shrubs away to improve their view of the bay, others have left the vegetation and even planted some trees to protect the fragile shoreline.
A few have even installed piles of the coarse-stone barriers called rip-rap. While this may protect one area from erosion, it can increase the wave action in the areas that are unprotected.
"That is part of the analysis that needs to be done," Edgerton said.
He explained that a good design can prevent wave action deflection.
Edgerton's study compared modern topography with a study of the same area done in 1969 for the sewer installation.
"Some areas have very little loss, some areas have as much as 10 feet," he said.
Edgerton offered multiple solutions, including planting vegetation to stabilize the shore, geo-textiles to hold land in place and dumping rip-rap in highly erodible areas.
However, before any of these solutions can be worked out, the town will have to determine how to mitigate an issue on privately owned property. While the town does have easements to access the sewer infrastructure, it does not have maintenance easements for erosion issues.
"If they want to protect town roads and the erosion is exacerbated by town infrastructure, like the stormwater drains, then the town should pay to mitigate that," said Rodden. "But some neighbors are willing to split the costs."
While Rodden said she would be willing to chip in for the mitigation costs, other neighbors believe like the town should pay to protect the town's infrastructure.
"I think private property owners have an interest in granting easements for the town to maintain its infrastructure," said Mark Kaplan, who lives at the corner of McKinley and Shoreline drives.
However, Kaplan said he did not think property owners should pay for the mitigation.
"With private rights come private responsibilities," Councilor Cathy Breen said during the meeting.
Breen cautioned against spending public taxpayer dollars on private land, stating that this could set a precedent for the way the town handles public/private partnerships in the future.
"Significant public contributions should come with significant public access," she said.
Town Manager Nathan Poore explained that no public monies could be used to secure private property.
"This truly started because of the public infrastructure," he said. "We could not have spent $1 on a study for private property."
Edgerton explained that it would cost approximately $30,000 to $40,000 per 100 feet to prevent the erosion. He suggested the first phase of mitigation should include 300 to 400 feet, which would keep the public infrastructure protected for five to ten years. This would include only four properties along Shoreline Drive.
"The issue of property rights and easements is more difficult than designing the mitigation," said Edgerton.
He said the town could apply for FEMA money made available to prevent disasters, however cautioned that competition for that money was fierce.
The council gave the go-ahead for town staff to investigate the best way to negotiate the property rights issues and to refine the limits and costs of the mitigation. The work will require several permits from the Maine Department of Environmental Protection and the U.S. Army Corps of Engineers.
The first phase of project is on schedule to go out to bid in May 2011.
Emily Parkhurst can be reached at 781-3661 ext. 125 or firstname.lastname@example.org