June 26, 2023

Prior To Major Event

1. Did the distributor have any prior warning that the Major Event would occur?

Yes, thunderstorms were forecasted; however, the severity of the lightning exceeded what was expected.

2. If the distributor did have prior warning, did the distributor arrange to have extra employees on duty or on standby prior to the Major Event beginning? Brief description of arrangements, or explain why extra employees were not arranged.

Hydro Ottawa had all of its employees on standby and on-site during the onset of the event. In addition, Hydro Ottawa had a full complement of on-shift personnel, a full on-call roster of field technicians and management personnel working overnight.

3. If the distributor did have prior warning, did the distributor issue any media announcements to the public warning of possible outages resulting from the pending Major event?


4. Did the distributor train its staff on the response plans for a Major Event? 

Yes. Hydro Ottawa has an established Electrical Emergency Response Plan and Organization, which includes processes and procedures for which staff are trained on.  Formal training is completed annually according to Market Rules.  In addition, weekly preparation meetings are held to refresh on-call management personnel.

During the Major Event

1. Please identify the main contributing Cause of the Major Event as per the table in section of the Electricity Reporting and Record Keeping Requirements.

  • Loss of Supply
  • Lightning
  • Lightning
  • Adverse Weather - Wind
  • Adverse Weather - Snow
  • Adverse Weather - Freezing Rain/Ice Storm
  • Adverse Environment - Fire
  • Adverse Environment - Flooding
  • Others

1.1. Please provide a brief description of the event (i.e. what happened?).

On June 26, 2023 there was a thunderstorm and lightning event that caused some significant outages: 1) 48M2 breaker auto reclosed at the Hawthorne TS station. The Blue phase switch was open with pitting due to lightning. 7241 customers were interrupted. 2) TB06 breaker failure due to a lightning strike which tripped the Y bus at the Russell TS station. 2363 customers were impacted. 3) UX02 and UX05 breakers tripped at the Gladstone station due to fallen trees from the thunderstorm event. 1266 customers were affected.

2. Was the IEEE Standard 1366 used to identify the scope of the Major Event? If not, why not?

Yes. Hydro Ottawa used the IEEE Standard 1366.

3. When did the Major Event begin (date and time)? 

June 26, 2023 at 3:40 PM

4. Did the distributor issue any information about this Major Event, such as estimated times of restoration, to the public during the Major Event? If yes, please provide a brief description of the information. If no, please explain.

Yes, ETRs were provided on social media (Twitter/X) and through the Outage Map

5. How many customers were interrupted during the Major Event? What percentage of the distributor’s total customer base did the interrupted customers represent?

15,413 customers were interrupted during the Major Event, representing 4.25% of Hydro Ottawa’s total customer base.

6. How many hours did it take to restore 90% of the customers who were interrupted?

97% of the interrupted customers were restored by 9:51 PM on 26th June, 2023.

7. Were there any outages associated with Loss of Supply during the Major Event? If so, please report on the duration and frequency of Loss of Supply outages.

Yes, there was one Loss of Supply (LOS) event from Hydro One in the Beckwith DS station on the BECKF2 circuit, that impacted 768 customers for a duration of 119 minutes.

8. In responding to the Major Event, did the distributor utilize assistance through a third party mutual assistance agreement with other utilities? If yes, please provide the name of the utilities who provided the assistance?


9. Did the distributor run out of any needed equipment or materials during the Major Event? If so, please describe the shortages.


After the Major Event

1. What steps, if any, are being taken to be prepared for or mitigate such Major Events in the future (i.e., staff training, process improvements, system upgrades)?

  • No further action is required at this time.
  • Additional staff training
  • Process improvements
  • System upgrades
  • Others

Additional comments:

HOL is undertaking a full review/update of its Electricity Emergency Response Plan.

Was this page useful container
Hidden Group

We'd like to hear from you

text and star group