Every year the ground settles and expands with the changing weather and temperatures. This affects both the height of overhead power lines and the depth of underground lines.
Overhead power lines
When the ground settles around them, power poles can settle. This can either cause lines to tighten or sag, with the latter increasing the risk of contact.
Typically, power lines are more than four metres above the ground. If you notice overhead power lines in your area are hanging lower than this, please contact your local utility company. We can make the required repairs to adjust the height of the line.
This is just one of the many reasons that it is important to maintain a seven-metre safe distance from any overhead power line. If your work requires you to work closer than seven metres, contact your local utility before you begin any work.
Underground power lines
Although utilities are buried well below the surface, freezing conditions in the fall and winter, along with the spring melt, can impact the grading of soil. Most of the time this results in the compaction of soil causing power cables to migrate to shallower ground.
The means that some underground utilities are only a few centimetres below the surface, making them much closer than you think and easier to contact and damage. Always know your locates before you start any excavation, practice safe exposing rules and hand expose when necessary.
For more information on the safe excavation requirements in Alberta, please see: Alberta Occupational Health and Safety Code, Part 32 Excavating and Tunnelling, in particular:
- Disturbing the ground (Section 441)
- Locating buried facilities (Section 447)
- Exposing buried facilities (Section 448)
Also consult the Alberta Electrical and Communication Utility Code for excavation work in the vicinity of underground power lines (Section 2-020).