Hydro One's transmission corridors, or Right-of-Ways (ROWs), are essential in delivering safe, reliable and affordable electricity throughout the province. They allow Hydro One 24/7 access to the towers and lines for routine maintenance and in emergency situations.

Many ROWs also have sufficient space to provide for expansion of Hydro One's facilities to accommodate future growth. The ownership of ROWs is diverse and includes government, Hydro One, private property owners, railway companies, and Indigenous communities

The Ontario government has established a Provincial Secondary Land Use Program (PSLUP) that allows for the use of ROWs, while taking into account the primacy of use of these lands is for electricity transmission and distribution. 

Hydro One strives to work with proponents to review secondary land use proposals on the ROWs so that they are compatible with the safety and maintenance requirements of our high-voltage equipment. 

Provincial Secondary Land Use Program (PSLUP) 

To learn more about PSLUP and the process for submitting a proposal, please visit Infrastructure Ontario's website for details. Below are some of the key steps in the process. 

  1. If you are a proponent interested in submitting a proposal, please contact Hydro One's Real Estate group at RE@HydroOne.com with any questions you may have. 

  2. A Real Estate representative will confirm the ownership of the ROW location and advise if the proposal is a permitted use. 

  3. The proponent will then be required to submit a written proposal to include contact information, a sketch/plan showing the proposed area and use, Hydro One facilities, confirmation that municipal planning consultation has occurred, and a non-refundable review fee. 

  4. The proposal will undergo Hydro One's review process to ensure technical compatibility with our transmission assets. As part of the review, Hydro One may require additional studies (e.g., grounding, induction or micro-shocks) which will be at the expense of the proponent.

  5. The proponent will be responsible for any municipal planning approvals, environmental studies, and appraisals as required, and at its expense. 

  6. If approved, the proponent agrees to the terms and conditions of use, including payment of all applicable fees and charges. 

  7. An agreement is prepared by Hydro One and signed by the proponent and Infrastructure Ontario. 

Important Considerations

When preparing a proposal, there are a number of technical considerations that should be kept in mind. A number of these are outlined below. Please note that this is not intended to be a comprehensive list of requirements, but aims to serve as a guideline to prepare a proposal. Reviews for each proposal are conducted individually by Hydro One and may require several weeks or months to complete depending on the complexity of the proposal.


Transmission conductors (wires) are dynamic in nature. They can sag lower to the ground depending on parameters such as ambient temperature and operating conditions. Minimum vertical clearances must be maintained from the maximum design sag levels of the conductors (worst-case scenario). Hydro One will review these clearances as they are case-specific and not immediately apparent by observation alone.

Infographic: Vertical Line Clearances under Transmission Lines



An unhindered, minimum 6-metre wide access path to facilities on the corridor must be provided for maintenance vehicles. A 15-metre clear working radius around transmission structures is required in order to maintain access for vehicles carrying out routine maintenance. A 3-metre radius around each tower footing must be left unpaved for access to the footing.

photo example of Hydro One vehicles working around a transmission tower which demonstrates why a 15-metre clear working radius is required 

Hydro One crews use heavy equipment to perform maintenance work on a 500 kV transmission tower.


  • Grading changes must not impact vertical clearance requirements or result in standing water anywhere along the corridor.

  • No fill material may be placed on the ROW without written approval from Hydro One.

  • Catch basins that are not positioned within a paved roadway are not permitted.

  • Stormwater management (SWM) ponds placed under 115 and 230 kV transmission lines cannot exceed two-thirds of the corridor width.

  • SWM ponds under 500 kV transmission lines cannot exceed one-third of the corridor width.

  • SWM ponds must be designed to withstand the effects of 100-year storm conditions.



Roads crossing the ROW should be perpendicular to the hydro corridor. Curb cuts or access gates should be provided for Hydro One maintenance vehicles. Parking facilities on 115 kV and 230 kV ROWs should be restricted to passenger vehicles only. Large truck and trailer parking is not permitted. Parking facilities are not permitted under 500 kV ROWs. Transmission towers near roads and parking areas must be protected by standard highway barriers.


All underground facilities must be designed to withstand the loading conditions created by heavy maintenance vehicles that may be used by Hydro One. The ROW must be restored to pre-construction condition once the project is completed. Excavation using heavy machinery is prohibited within 10 metres of tower footings to protect foundations. Within 10 metres, excavation must be carried out by hand or by use of a VAC system. Pipelines on ROWs must adhere to the provisions of CSA Standard C22.3 No. 6.



Plantings which grow to a maturity height over 4 metres are not permitted on the ROW. These low-growing shrubs are permitted to be planted on ROWs, including: Gray Dogwood, Red Oiser Dogwood, Alternate Leaf Dogwood, Cornus racemosa, Cornus sericea, Cornus alternifolia, Elderberry, Sambucus Canadensis, Forsythia, Forsythia ovate, Honeysuckle, High Bush Cranberry, Lonicera spp., Viburnum trilobum, Mugo Pine and Pinus mugo mugo. 

These shrubs should be planted in such a way as to not impede access to the transmission towers. An area of 15 metres around transmission towers should be kept clear of shrubs to permit Hydro One access to towers.

All plantings must be consistent with the Hydro One-approved species list and the overall plan is subject to Hydro One’s approval. Visit Vegetation Management for more details.

  • Buildings and permanent structures are not permitted on ROWs. 

  • Flammable or hazardous materials may not be stored on ROWs. 

  • Consideration should be given to minimizing the use of conductive (metallic) material where alternatives exist (e.g. fences). 

  • The proponent is responsible for all costs of modifying, relocating, or monitoring Hydro One assets as a result of its proposal.

  • The Canadian Energy Regulator (CER) regulates international power lines in Canada. The CER has issued two regulations under the Canadian Energy Regulator Act that establish requirements that individuals or companies must follow, including obtaining Hydro One’s authorization to construct a facility in the proximity of an international power line, cause a ground disturbance within the right of way area of an international power line, and/or operate a vehicle in close proximity to an international power line.

    The CER regulations can be found on the Government of Canada’s website below: