Future of Garden Hill Dam debated as Port Hope Council asked for financial support

Garden Hill Dam. Photo courtesy of the Ganaraska Region Conservation Authority Facebook.

By: Dan Jones, Northumberland 89.7 FM News, Local Journalism Initiative

The Garden Hill Dam on the Ganaraska River is facing an uncertain future.

The Ganaraska Region Conservation Authority, which built and owns the 66-year-old structure said it is in need of significant repairs, but cautioned that if restoration does not proceed, the dam may need to be decommissioned.

Cory Harris, Watershed Services Coordinator with the environmental group presented to Port Hope Council Tuesday night, requesting funding for the two-year project.

A 2023 dam inspection report found deficiencies in that installation of additional erosion protections, re-seal the construction joints between the upstream wingwalls and abutment walls, and replacing the deteriorating stoplogs would be needed. The leakage from the bottom stoplogs of the dam is now considered significant, as Harris suspects those stoplogs were originally installed in 1959.

“One of the big reasons that we’re bringing this forward now is that we’ve seen a rapid deterioration of the stoplogs within the dam. Our concern here too is at the current rate of deterioration, we’re going to be in a position here shortly where we are not going to be able to maintain a water level in this reservoir,” said Harris.

The Conservation Authority currently does not have the funding to complete the needed repairs to the dam and is requesting a cost sharing with Port Hope and the province, requiring the municipality to pay approximately $340,000. The dam and reservoir is home to fish, wildlife, turtles, and frogs and is used by the Port Hope Fire Department. Year One of the repair process would comprise environmental assessments and design, with the actual work itself the following year.

Harris outlined what decommissioning of the dam would look like stating it would cost similar to repairing the structure as much of the same repair preparation work would be done with decommissioning.. While much of the questions from council focused on monetary commitments, several asked about decommissioning, with Harris explaining it would not be catastrophic to area wildlife.

“To look at decommissioning is not all bad. If we could get offline ponds we could maintain some of that habitat. You could even get fish passage back through this area if we did a rocky ramp through the culvert. So, there are pros and cons to each but, I know the local community is very attached to this reservoir,” Harris said.

Council did not make a decision on the proposal Tuesday night, rather receive the presentation for informational purposes.