In a single storm last Thursday, more rain fell in Sackville than in the entire month of August combined. According to Environment Canada, Sackville saw 81.6 mm of rain on Thursday, September 2. The heavy rain filled the town’s new retention pond, had sewage pumping stations working at capacity, and caused isolated flooding at spots throughout town.
Town engineer Dwayne Acton says that overall, town infrastructure fared well, but that might have to do with some lucky timing in terms of the tide cycle. “During the heat of the storm we were somewhat on low tide,” says Acton. But if the worst of the storm had come at high tide, “we might have seen a different story.”
“We had some very intense times throughout the storm,” says Acton. “The retention pond did a fantastic job in holding the water that was coming down to Lorne Street.” But Acton points out that despite the storm not hitting one-in-100-year levels, “the pond was basically at the brim.”
The pond did overflow onto St. James Street at one point in the storm, and the pathway along St. James was flooded as well.
“If we ever hit the one-in-100-year storm, I can assure you that we don’t have the the capacity in that one retention pond to deal with all the stormwater,” says Acton.
The town currently has an outstanding funding application to the Integrated Bilateral Agreement for green infrastructure to access federal and provincial funding to complete phase III of its Lorne Street Stormwater Mitigation Project.
ISOLATED FLOODING ON SOME ROADS, INCLUDING HIGHWAY 106
There was also isolated flooding in some expected spots, such as along Ogden Mill Road and Walker Road, says Acton. And there was flooding at the Mount Allison heating plant at King and Main. “We did attempt to close the road down,” says Action, “but the water quickly dissipated.”
The area near the booster pump on Main Street normally floods, says Acton, but was spared thanks to a new storm system put in recently by the town. “There was no flooding there,” says Acton. “We were quite pleased with that.”
The 106 headed westward to Dorchester did flood, with water across both lanes late Thursday evening, and dissipating to a single lane by Friday morning. “It wasn’t what it was in the past”, says Acton, who credits new aboiteaux installed by the Department of Transportation and Infrastructure (DTI) in 2018-19 as having helped drain the water this time around.
The Wood Point Road (route 935), which meets the 106 near where it flooded, did not flood during this storm, likely thanks to the new aboiteaux.
But Acton says town staff were concerned. “The Carter’s Brook and all the bridges… the water was just right up to the to the underside of the bridges,” says Acton. “So there was some nervous times for us throughout this whole event.”
CN TRACKS CAUSING A FLOODWATER BOTTLENECK
One key problem, says Acton, is with CN tracks along the 106. “We need CN to step up to the plate here and work with us because the water can’t get through the tracks,” says Acton. “It’s a bottleneck.”
Acton says the town has met with CN to discuss the issue, but there’s a disagreement about what is sufficient. “We’ve been telling them and trying to work with them but they feel that they’ve got more than adequate piping and infrastructure under the tracks there,” says Acton. “And they don’t.”
“We keep trying to tell them they don’t have the right infrastructure in the right spots,” says Acton. “Without CN working with us and getting more capacity underneath the tracks, it’s going to continue to be an issue in the future.”
Acton says that CN did have a truck and workers on scene Thursday night, so he’s hoping that concern for a possible track washout will lead to investment in more stormwater infrastructure through their tracks.
Local area residents have also expressed concerns over the silt build up around the new aboiteaux on Wood Point Road. Muddy tide waters drop plenty of silt at the gates at high tide, and the build up appears to have blocked off some of the gates.
Acton says that silting was a concern for himself and DTI, but that Thursday’s storm has washed away some of that silt. “The thing with the silting is usually when you get an event like this, all that silt that’s deposited near those new aboiteaux is washed back out because of the intensity and the amount of water that’s going through,” says Acton.
SEWAGE LIFT STATIONS AT MAX CAPACITY THURSDAY
Thursday’s storm wasn’t just a challenge in terms of stormwater storage capacity, but sewage capacity as well. “A storm like this is a huge strain on our sanitary system as well because of all the infiltration of stormwater into the sanitary system,” says Acton.
While new houses are required to divert stormwater to ditches, older houses and buildings often have sump pumps emptying into the sanitary sewer system.
“It definitely put a strain on the system,” says Acton. On Thursday, public works staff patrolled lift stations and found them maxing out. “We were lucky that we were able to keep everything up and running,” says Acton.
He says he urges people to install back flow prevention on their sanitary and storm sewers in their homes. “Because if those lift stations are maxed out or they fail, you could get sewage that could back up in your house,” says Acton. “We encourage, and the bylaw encourages, everyone to ensure that they have backflow preventers in their houses.”
