No easy fix; Station Street in Hillsburgh may be closed well into the new year

Hillsburgh residents should not expect the early Christmas present of having Station Street open by the end of the year.

In fact, according to discussions at a special council meeting on Dec. 14, it could be quite some time before the road reopens. In late October, staff noticed a section of Station Street across a privately owned dam and causeway had started to shift. Once information began pouring in, council’s decision was to close the road.

Although the special council of Dec. 13 was slated to discuss the town’s five-year capital budget and how council would proceed with a proposed committee of the whole structure, councillors agreed to push road superintendent Larry Van Wyck’s report to the forefront.

He said recent investigations had road crews checking a bump in the road and odd gurgling noises, and water bubbling to the surface. He said on the north side of the road, the water is bubbling up as high as five feet.

“We started looking at this because what is happening is not normal,” he said.

He agreed noise from the site is not unusual – according to people who live nearby.

But the road moving is not normal.

Van Wyck said, “The road has moved five to six inches since Oct. 26.”

Currently, the road is not moving, but he still has concerns.

He referred to ground penetrating radar that sent sound waves into the ground and the results are interpreted to give an idea of the subsurface conditions. “It’s like an ultrasound for the roadway.”

That report indicates a void.

“The fact there is a void there doesn’t mean there is a cave or a cavern – it could be water. It just says there is a void,” Van Wyck said.

But once the radar registered the void “We really had no choice, in case it is a cavern. We tried to get inside the pipe to find out what the condition was. On the upstream north side of the road, that concrete vault has two sets of boards in it.

Van Wyck said the first thing staff had to do was get to the vault [located in the pond] to determine what was happening. Part of the problem lies with the water running in through the boards down into the vault structure.

“Water continues to come in at a fairly rapid rate.”

Workers tried to put a sewer camera down – but those items typically do not operate when totally submerged. While staff managed to get the camera in the pipe, it could not go further. The pipe is 100% full of water from the north side.

Van Wyck noted staff built a gangway to reach the vault. At that point additional boards were placed and a sheets of plastic set in to stem the water.

However, in one place there are holes in the older, weathered boards and the water is traversing it as if there is no obstruction in place.

“It’s not just one board leaking, there’s more further down,” Van Wyck said.

He said the area of concern is at the centre line of the road.

“There was concrete sticking out which had a straight edge.”

That was removed and cold mix asphalt placed over the area. Van Wyck said at some point in its history, the municipality placed eight cubic metres of concrete in a hole there.

“I have no idea why the north side is showing up as the void.”

He suggested if there was a hole in the culvert when the concrete was poured, it may have stopped the flow of water.

However, the concrete itself may be hiding where the problem is. Downstream, the water emerges via a corrugated steel pipe that is completely underwater. There is significant water pressure involved, and the recommendation is no one stand near or in front of it, Van Wyck said.

He noted the old mill race is no longer functional and on the north side, it has been buried. He said the mill race has not functioned for some time.

He added the bottom of the dam is significantly higher than the bottom of the intake pipe, which is four metres below the surface of the water.

“So even if you took all the boards out of the dam itself, there would still be water” streaming into the other structure.

In addition, Van Wyck said there is some deteriorated concrete on the [privately owned] dam. “It’s been neglected and is in need of attention.”

He said based on some of the pipes removed from the ground in Erin, there could be even more of a problem than originally suspected. He cited numerous examples where the galvanizing on pipes has rusted away.

“It’s a fairly common thing we’re starting to see on steel pipes in the 30 year and older range – which we are assuming this is.”

Van Wyck said a lot depends on the acidity of the water, which affects the galvanizing on the steel.

“But once it is gone, there’s not much life left in that pipe.”

He said with the water pressure, “We have a serious problem.”

There have been discussions with the landowner, who has been cooperative.

“But a decision is going to have to be made by the town as to how much it is going to contribute. The fact that we don’t own the dam or the inlet structure is very clear. But we do own the road.”

He added, “To the best of my ability, I have not been able to find any documentation regarding the pipe which goes from one side of the road to the other.”

Councillor Barb  Tocher said if the overflow structure was not leaking, the dam would be functioning properly.

Mayor Lou Maieron asked if there was any way of tracking the history of the property and its structures. He suspected the overflow structure in the pond, being four metres deep, indicates that at one point there was the ability to drain the pond.

Tocher agreed.

She believes the last time the pond was drained was in the 1960s. At that time, the silt would be cleaned out, she said.

“It’s a man-made pond.”

Van Wyck said the municipality must find out what is wrong, and the flow of water must first be stopped. But with the water pressure through the pipe, “There’s nothing you can do.”

Tocher concluded, “Which means draining the pond.”

Van Wyck said there are alternatives, but there are costs involved.

Plus there are questions about the bottom of the pond.

He said with the degree of work required, the town would have to hire equipment.

Maieron asked what would happen if all the boards are removed to allow the pond to drain.

Van Wyck was uncertain the municipality could get permission from the Ministry of Natural Resources to drain the pond during the winter.

Maieron asked how much the town wants to spend, since the dam does not belong to Erin and is controlled through the MNR.

Tocher suggested it may now be time to put the property owner on notice and the owner will be held responsible for damages caused, and that the structure needs to be fixed.

She again questioned why the state of the overflow intake structure and dam should be considered a municipal responsibility. “It is private property.”

Van Wyck said the ministry will not allow the pond to be drained completely in the winter – unless there is a threat to public safety or property.

“Their initial response is that this is not.”

To Van Wyck it means the town might be allowed to lower the water somewhat, but not to drain it at this time of year.

He said the MNR is concerned draining the pond now would be detrimental to the wildlife buried in the shallow mud.

Tocher said if the solution means waiting until spring, then unfortunately, the road will remain closed until the problem is solved.

Van Wyck said a contractor’s estimate to deal with the work could be $50,000 or more.

Maieron agreed there is no way of knowing there is a problem with the pipe until it can be examined. “But some forces have caused the road to lift, to sag and to settle.”

He said one idea proposed to him is to span the void with a steel plate, and use asphalt to hold it in place.

Van Wyck said if one is dealing with the bottom out of a culvert, “I don’t think you should bridge it without a knowledge of what is underneath.”

Tocher said, “Obviously there is a problem underneath and bridging it with steel, the problem still exists and would be washing away the earth. Eventually it would be large enough that the steel and everything would collapse.”

Van Wyck said if the pipe is solid it would not be an  issue. “Right now, we don’t know.”

Tocher asked how much the municipality has spent on the issue .

Van Wyck said there was $1,500 for the ground penetrating radar, construction of the walkway, some time from Triton Engineering, and staff time of probably 40 to 50 hours.

Councillor John Brennan said even if the town does all that work, it still does not know who owns the culvert. He wants to know if the investigation would definitively identify the problems with the dam.

Van Wyck said unless there is legal identification of the culvert, he doubt any issues with the culvert could be identified with the dam.

Tocher said if the overflow structure is failing, it is causing problems regardless of the ownership.

“It is causing damage to the culvert under the road.”

Van Wyck did not disagree but pointed out the town owns the road and there is a culvert underneath it.

“Where do we go from here?” Tocher asked.

Brennan said, “Either we spend the money, or we close the road until next year.”

Tocher doubted council even has an option of fixing the road this year.

Van Wyck said the most frustrating part is being unable to decide until there is a better idea of what the problem is.

“I can’t tell you how or when this is going to be fixed, because I don’t know what it is going to take to fix this.”

Part of the problem is that the overflow pipe is located within the pond, some five metres away from the road (shoreline).

Van Wyck said according to Credit Valley Conservation and the MNR, most of the pond is only a metre deep. The water intake structure is the deepest part of the pond.

“It’s deep enough to drown in,” Tocher said.

Van Wyck said, “Without stopping or lowering the water, we can’t do anything. And how far do we go, when it is not our structure letting the water through?”

Tocher said it seems clear the ball is in the owner’s court.

She also believes the purpose of the intake structure no longer serves its function, because the pond is no longer drained.

Council anticipated another report at its Dec. 20 meeting.