An effort to recognize Erin’s eight major ponds as sites of heritage
interest is a new twist in the ongoing debate over dam safety, the cost of
maintenance and the impact of allowing the West Credit River to return to a
meandering stream.
Only two of the dams for those ponds are publicly owned. A question
mark still hangs over the Hillsburgh millpond, now jointly owned by the county
and the town. An environmental assessment recommending its preservation has
been appealed to the Minister of the Environment, but no decision has been
announced.
More attention is turning to Hull’s Dam, which creates the upper
pond near Church Boulevard in Erin village. Its concrete has been crumbling for
decades, and now Credit Valley Conservation is urging the town to order an
engineering assessment.
If the hazard potential is high, there could be a Dam Safety Review
(DSR). The initial cost could be from $50,000 to $150,000, possibly offset by
government funding. A DSR could lead to major upgrades, with a plan for
inspection, maintenance and emergency response.
 |
| West Credit River and Lower Pond, south of Hull's Dam |
Or the town could decide to decommission the dam, which would
require yet another environmental assessment. CVC generally favours
decommissioning since it improves fish habitat and reduces flood risk, but it
also can remove a cultural landmark and drastically alter the local eco-system.
John Sinnige, Senior Manager, Water Resources and Flood Risk, at
Credit Valley Conservation (CVC), told council last month that the town has an
obligation of “due diligence” for the dams it owns.
“This means safe operation, maintenance and monitoring,” he said. “The
Church Street [Hull’s] and Charles Street dams are probably some of the biggest
concerns right now. If the Town of Erin is concerned about a privately-owned
dam, they should contact the MNRF (Ministry of Natural Resources and
Forestry).”
 |
| Ainsworth Pond, south of Station Street. |
Public and private owners are liable if a dam failure causes damage.
Sinnige said CVC tries to warn owners in the watershed of the risks and to
offer advice.
“There are some of the major dam owners who, believe it or not,
don’t like the CVC and just don’t want to deal with us at all. They just say,
‘Keep out of my business’, and there’s nothing we can do about it.”
The MNRF has primary responsibility for dam safety, but do not get
involved unless there is a serious problem. Normally, neither the MNRF nor CVC
can force a dam owner to upgrade to modern standards.
 |
| Hillsburgh Millpond at dusk |
Erin’s Heritage Committee recently passed a motion urging council to
list all the major ponds on its Heritage Registry, a list normally used for
older buildings. This comes after the privately-owned Rudd pond south of
Hillsburgh was decommissioned, with no requirement to notify council or the
public.
“We should ask the County of Wellington planning staff to provide us
with a report on what the options are and the implications,” said Coun. Jeff
Duncan at the December council meeting.
“The West Branch of the Credit River probably has one of the highest
concentrations of existing and historic mill ponds, in the five kilometres from
Erin to Hillsburgh.”
In addition to Station Street and Hull’s Dam, there are dams for the
Ainsworth Pond, Thomson Lake (Olesovsky) and Roman Lake (an off-line pond with two
dams) south of Hillsburgh. In Erin village there are private dams for two off-line
ponds in Stanley Park, plus the privately-owned Charles Street dam, which creates
the lower pond near the downtown core.
Adding a building (or pond) to the Heritage Registry does not stop
an owner from getting rid of it, but it would require a 60-day public notice
period. During that time, the town could investigate options for preservation
and could take the unusual action of a Heritage Designation, which would
prohibit demolition.
Duncan said the Heritage Committee has a mandate to deal not only
with buildings but landscape features of cultural interest. He said heritage is
studied when removal of a public pond is considered, and that there should be a
process that recognizes both the heritage aspect of a private pond and the
effect on other landowners.
Mayor Al Alls said the town had a complaint about fish being killed
by the release of silt, and the town didn’t even know it was happening.
“There’s got to be a better process,” he said. CVC CAO Deborah Martin-Downs agreed
that better communication would help “make the air clearer”.
Alls also said he “kind of supports” the request to put ponds on the
Heritage Registry. “I just worry that we are trampling on private rights,” he
said. Council made no decision on listing the ponds, but did agree to request a
county report.
The CVC presentation to council came after Coun. Matt Sammut
previously raised the question of what the Town of Erin could do to reduce the
risk of a dam failure, which would endanger life and damage property.
 |
| Hillsburgh Millpond after sunset |
Sinnige said Erin has nine major dams and 118 minor ones, based on a
survey done in 2005. He said that in 2011, after a section of roadway over the
Station Street dam became unstable, CVC did a confidential, preliminary study
of what could happen if the dam collapsed.
“There was a possibility that all ponds in Hillsburgh and Erin could
be breached due to a cascading effect,” he said. “There was limited information
available to conduct calculations. Assumptions were made due to timeline and property
access issues.”
That report was never made public, but it did reinforce the MNRF’s
demands that Erin come up with a solution for Station Street.
“We don’t like to make it public because of the assumptions and
limitations of the study,” he said. “We don’t want it to be interpreted
incorrectly.”
Emergency work was done at Station Street to stabilize the dam. The
CVC report went to the county, and in 2015, Community Emergency Management
Coordinator Linda Dickson finally made a public report to Erin council.
The county review estimated that a Station Street failure would
break down the Hillsburgh dams, but only overflow the Erin village dams.
Sections of Trafalgar Road and Eighth Line, along with residential lots in
Stanley Park, downtown business properties next to the pond and areas
downstream of Charles Street, would be under several feet of water.
That report does not put a dollar value on potential damage, but
says such an event would be rated as a one-in-50 year flood, slightly less than
the current flood lines on Town planning documents.
