Guidelines for development within 30 metres of a watercourse

If a person wants to do any work near a river, stream, wetland or lake, a permit is required from the minister as per the Clean Water Act. Individuals can apply for a Watercourse and Wetland Alteration permit online.

If your project disturbs soil within 30 metres of a watercourse or lake, there are guidelines to follow. These guidelines are meant to:

• protect the environment
• keep the areas along water healthy
• make sure decisions about permits are consistent and fair

For more information, consult the Watercourse and Wetland Alteration Permit.

These areas are ecologically sensitive and may pose additional risks to people and infrastructure, particularly in areas prone to flooding. It is important to minimize development in these areas for the benefit of nature and people. If your project is located within 30 metres of a lake or a watercourse that is prone to flooding or influenced by tide, it should be planned as per the following guidelines. 

For these guidelines, the term developed is defined as a property that already contains a habitable structure (e.g., house, cottage, camp, apartment building) with septic system and well (or connected to municipal services), or a commercial/industrial building. 

For these guidelines, the term flood prone area (or prone to flooding) is used for properties that are known to have flooded during past flood events.

Properties that are already developed

Rebuilding or replacing of a dwelling or commercial/industrial building:

• should be planned to be further away from the watercourse or lake, if possible, if this is not possible, a rebuild/replacement may be permitted, provided it is no closer to the watercourse or lake than the current/previous footprint 

Expanding a dwelling or commercial/industrial building:

• may be permitted provided it is no closer to the watercourse or lake than the current structure   

Infilling of properties: 

• infilling for the purpose of raising the grade of a property is not permitted within 15 metres of lakes  
• infilling for the purpose of raising the grade of a property is not permitted within 30 metres of watercourses prone to flooding or influenced by tide 
• fill may be placed adjacent to a foundation wall, with a gentle slope down to the ground, to ensure foundation stability and positive drainage away from the structure  
• fill may be used to repair damage or to level a property, provided the height of the grade is not increased 

Accessory structure on a new slab or foundation: 

• may be permitted no closer than 15 metres from a watercourse or lake and only if the area for the proposed structure is already cleared/landscaped  

Accessory structure on blocks/posts or fill/gravel pad: 

• may be permitted no closer than 6 metres from a watercourse or lake and only if the area for the proposed structure is already cleared/landscaped  
• structures approved between 6 and 15 metres of the watercourse or lake should have a maximum footprint of 25 square metres

Properties that are not developed 

Construction of new dwelling or commercial/industrial building:

• not permitted within 30 metres of a watercourse or lake

Infilling of properties: 

• infilling for the purpose of raising the grade of a property is not permitted within 15 metres of lakes 
• infilling for the purpose of raising the grade of a property is not permitted within 30 metres of watercourses prone to flooding or influenced by tide 

Accessory structure on a new slab or foundation:

• not permitted within 30 metres of a watercourse or lake 

Accessory structure on blocks/posts or fill/gravel pad: 

• may be permitted no closer than 15 metres from a watercourse or lake

All watercourses play a vital role in surface water drainage across the landscape and provide important habitat and water inputs for aquatic life, other animals, and humans. Maintaining a healthy and intact riparian zone is crucial for supporting watercourse health and allowing natural change over time. If development is necessary within 30 metres of a watercourse, projects should be planned in accordance with the following guidelines. 

Properties that are already developed 

Rebuilding/replacing of a dwelling or a commercial/industrial building:

• may be permitted provided it is no closer to the watercourse than the current/previous footprint 

Expanding a dwelling or commercial/industrial building:

• may be permitted provided it is no closer to the watercourse than the current structure   

Infilling of properties:

• infilling for the purpose of raising the grade of a property may be permitted no closer than 6 metres from a watercourse 

Accessory structure on a new slab or foundation: 

• may be permitted no closer than 15 metres from a watercourse and only if the area for the proposed structure is already cleared/landscaped 

Accessory structure on blocks/posts or fill/gravel pad:

• may be permitted no closer than 6 metres from a watercourse and only if the area for the proposed structure is already cleared/landscaped 
• structures approved between 6 and 15 metres of a watercourse should have a maximum footprint of 25 square metres 

For properties that are not developed  

Construction of new dwelling or commercial/industrial building: 

• may be permitted no closer than 15 metres from a watercourse

Infilling of property: 

• infilling for the purpose of raising the grade of a property may be permitted no closer than 15 metres from a watercourse 

Accessory structure on a new slab or foundation: 

• may be permitted no closer than 15 metres from a watercourse 

Accessory structure on blocks/posts or fill/gravel pad: 

• may be permitted no closer than 15 metres from a watercourse

The 30-metre area adjacent to the watercourse is determined by taking a horizontal measurement (i.e., bird’s eye view). This measurement should be taken in the field and not based on mapping tools. 

For watercourses that have a defined channel with flowing water: 

• find the top of the bank (also known as the shoulder of the bank), from this point, measure 30 metres going away from the watercourse (horizontally) to determine the area requiring a permit 

Note: Watercourses meander; several measurements may be required to determine the 30-metre line on the property. 

For lakes, ponds, or watercourses that have no apparent bank: 

• find the line where permanent vegetation starts to grow, from this point, measure 30 metres going away from the watercourse (horizontally) to determine the area requiring a permit

Most construction projects require approval and permits from the Regional Service Commission, city, town or municipality. In some areas, local by-laws may require additional permissions or setbacks for vegetation removal, excavating, etc. It is the landowner’s responsibility to ensure that all permissions and approvals are obtained prior to commencement of the project. Obtaining a Watercourse and Wetland Alteration Permit does not exempt applicants from other regulatory requirements. If local by-laws impose stricter conditions than those outlined in a permit, the more stringent regulations will apply.