Melting snow and today’s rain will test Potsdam’s runoff drainage system work
By CRAIG FREILICH
POTSDAM – The melting snow and today’s rain should be “a good test” of the work done on clearing the cross-town canal for better runoff drainage, village officials say.
“We should get really good sense of how well the work we did this summer turned out,” said Village Administrator Greg Thompson.The work, which cleared a section of the canal that was being blocked, improved storm drainage in an area east of Market Street toward Leroy Street.
While that work on the canal helped, more needs to be done, Thompson said.
One consequence of the summer’s canal work was some flooding along Willow Street, on the route of the canal on the west side of Market Street on its way to the Raquette River.
Clearing the first blockage increased the speed of runoff flow to the Willow Street section, where a new bottleneck showed itself.
“That’s where our next play will be,” he said.
“The village is the low point of a bowl. Even if we fixed the canal, it can’t handle what we’re getting from inside and beyond the village,” Thompson said.
The canal, built 100 years ago, is sometimes overwhelmed by all the water it is asked to take today, he said. “Even if it was 100 percent in great shape, it’s not perfect.”
“Since then we have added concrete and blacktop in the village which increases the speed of ‘sheet runoff,’” which he describes as the accelerated movement of storm water on hard surfaces rather than over soil and vegetation.
A representative of the engineering firm that has been working on surface water drainage problems in the village told trustees Monday that the first phase of their work was successful.
“It went really well,” said Mike Tambline of Environmental Design & Research, Landscape Architecture, Engineering, & Environmental Services, D.P.C. in Syracuse.
Tambline explained that the century-old canal’s efficiency had been compromised by one water line and two sewer lines that “transected” the canal since it was built, creating blockages.
“Debris was hanging up on it,” Thompson said. Those lines were rerouted under the canal.
Tambline said that project was finished “on time and under budget.”
He said the village commissioned his firm to do a study of the drainage system. Their inspection, with little cameras, showed the tangle around the lines in the canal.
“We have taken care of the immediate needs,” Tambline said, while they work on inspecting the rest of the system to find out what more needs to be done.
“That was the first step” in the larger overall project, he said. His firm is working with the Development Authority of the North Country to see “what are the next steps,” including seeking grant funds for further work.
The drainage problem had been showing itself in the Leroy Street neighborhood for some time when, in 2010, a serious storm that was preceded by 28 days of measurable rainfall led to widespread flooding affecting about 50 homes in the Leroy and Clinton street neighborhood and around Pleasant Street between Waverly and Market streets.
The subsequent inspection revealed the problem with the crossed lines.
“From there they went looking 50 to 100 feet in either direction,” Thompson said. What they saw “was better than we thought.”
They are still conducting light inspections with small cameras. “Some places need to be cleaned up to determine the condition” of the rest of system, some of which is 150 years old.
“It can’t be put off,” said Thompson. “We have to get it on the radar so we can prove to the state that there is a need” for grant aid.
Tambline said he devised “a phased approach to achieve the goals by rehabilitating the system as it exists and deal with some blockages.”
The watercourse originally was an open canal devised to drain farm fields across Lawrence Avenue from where the elementary school is now.
It was eventually lined with rocks, timbers were placed over it, and it was covered with soil.
“That’s now deteriorating,” Thompson said.
With $50,000 set aside for an engineering study of the remaining work, “we want to get the study done as soon as possible. We need an up-to-date assessment to identify problems now and prioritize according to severity and cost.”
“We hope to tap into funding that’s available now” from state and federal sources for infrastructure projects, he said.