On Nov. 5 I undertook a site visit with representatives of HydroOne travelling the hydro right-of-way between Ontario Street to the north side of Graham’s Lane. Beginning the week of Nov. 16, HydroOne will be removing the vegetation within 55 feet of the center of the hydro lines on either side. They will be delivering a community notice (below) to residents along the corridor explaining this work.
When transmission lines are overloaded, especially with the summer heat and humidity, lines can sag 15 to 20 feet. On Aug. 14, 2003 an already overloaded transmission line sagged too low, causing a flashover to nearby vegetation and a surge in current. A software bug in the alarm system at an energy company in Ohio left operators unaware of the need to re-distribute power from the line, causing a massive widespread blackout affecting the US and parts of Ontario.
In February 2004, the U.S.-Canada Power System Outage Task Force released a report from its investigation, saying the blackout was due to four things, one of which was a failure to manage the tree growth in the transmission rights-of-way.
Since then, regulatory bodies have become more strict with maintenance around hydro wires. HydroOne is now required to remove all vegetation within both the “wire zone” and the “border zone” of hydro lines. (See diagram). From outside edge to outside edge is a 110 ft clearance, 55 ft on each side measured from the middle of the hydro tower.
What will be removed?
At one time, HydroOne would prune vegetation and allow trees to remain. Pruning and topping off is not an option anymore and HydroOne can face hefty fines from regulatory agencies.
Most of the vegetation on east side of the corridor falls within the 55 foot zone and will be removed. In addition, trees overhanging from private yards within 55 feet of the lines will need to be trimmed. Hydro One will be knocking on the doors of the affected properties.
The trees at the northeast corner of Elgin and Brock near the benches will be removed. Also, several residents have planted trees or shrubs in the middle of the hydro right-of-way in the northern end of the corridor. These are unauthorized plantings and will be removed (see photos below).
In addition, I am in conversation with city staff about using some funds to beautify the trail head at Ontario Street and the hydro corridor, by replacing the concrete blocks (photo right) with perhaps bollards. Those conversations are ongoing.
In the city’s master plan, a paved multi-use path is planned for the length of the corridor in 2018.
How will the vegetation be removed?
In some areas, workers will be on foot pruning. In other areas, grinders, excavators and bulldozers will be used. The vegetation that is removed will be replaced with grass only.
Beginning Monday, Nov. 9, HydroOne staff will be knocking on the doors of those residents that have vegetation in their yards that encroach into the hydro right-of-way. HydroOne will also be hand delivering a letter to all residents abutting the hydro corridor.
More information will be provided in the letter being hand delivered. Residents can email HydroOne at Community.Relations@HydroOne.com or telephone 1-877-345-6799.
I hate to see the trees and shrubs removed, but understand that this is the new requirement to ensure safety and uninterrupted power supply. Residents still have the option to plant privacy screenings on their side of the fence outside the corridor width. I will be working with staff to try to get some funding for improving the trail head area at Ontario Street, at the very least replacing the concrete blocks with more decorative posts that prevent vehicular traffic from entering the corridor.