Invasive Species

What is an Invasive Species?

Invasive species are plants and animals that are not native to our region and as a result, lack natural predators. Not all non-native species are invasive. For a species to be considered invasive, they would have a negative impact ecologically, socially or economically. Invasive species tend to grow rapidly, out-compete native species, and are challenging to manage, often requiring a dedicated management approach implemented over multiple years.

Invasive Species Management Bylaw 

The Invasive Species Management Bylaw requires landowners and occupiers to prevent growth and control the spread of invasive plant species on, to and from their land.

The Bylaw prohibits:

  • Sowing, planting, cultivating, releasing or allowing accumulation or spread of invasives;
  • Sale or distribution of invasive plants and animals; and
  • Treatment and disposal that do not adherence with methods endorsed, established or published by the Sea to Sky Invasive Species Council or the Invasive Species Council of BC, or as advised by a Qualified Environmental Professional and accepted by the District’s Environmental Staff.

 View the bylaw



As with all District of Squamish bylaws, the District aims to seek voluntary compliance, which is often achieved through education. Under the Bylaw, the District may deliver a notice informing a property owner/occupier of the presence of invasive species, recommended steps to treat the species, and a reasonable timeline in which they are to comply. In cases of non-compliance, the Bylaw enacts fines (up to $50,000) or enables the District to ensure compliance by performing the works at the land owner’s or occupier’s expense.

 Invasive Plant Disposal Protocol

Local municipalities and Sea to Sky Invasive Species Council (SSISC) have developed best practices for the disposal of invasive species throughout the corridor.  View the Invasive Plant Disposal Protocol.

Invasive Species in Squamish

Invasive species are the second most significant threat to biodiversity after habitat destruction by land clearing, according to the International Union for Conservation of Nature (IUCN 2017). The economic and environmental impacts of invasive species are also significant.

Invasive species grow rapidly, are hard to get rid of, and out-compete native species. Because they arrive in Canada without their natural predators to keep them in balance, invasive plants and animals can spread rapidly. Specific threats include:

  • Decreased biodiversity;
  • Altered water flow and leading to erosion and/or less available water;
  • Creating and increasing the fire hazard;
  • Damage to roads and other built structures;
  • Reduction of crop yield;
  • Recreational and tourism trails/areas choked by invasive monocultures;
  • Decreased property values; and
    a loss of medicinal plants and cultural practices (loss of wild edibles, loss of habitat for wildlife and fish).

Invasive plants and animals spread a variety of ways, including:

  • Dumping of garden debris into parks, ditch or wild areas.
    Purchasing and planting invasive plants for ornamental purposes.
  • Release of domestic pets (e.g., bunnies and goldfish).
  • Not cleaning, drying and draining boats and aquatic equipment before relocating.
  • Seeds transport by wind, water, animals, vehicles, soil movement, equipment and humans.
  • Transport of root fragments or stollens during the movement of gardening materials, soil or equipment.

The District of Squamish’s highest priority invasive species are Japanese Knotweed, Giant Hogweed, and Yellow Flag Iris, all of which are on the BC Weed Control Act’s Noxious Weeds List.

These species grow and spread aggressively, are highly competitive, difficult to control, and can be highly destructive to natural resources, infrastructure, industry, and human health.

Negative impacts:

  • Giant Hogweed causes severe burns to those who come into contact with it and may cause blindness.
  • Japanese Knotweed damages infrastructure, reduces the structural integrity of dikes and streamside banks, accelerates erosion, impedes traffic sightlines, and devastates riparian systems. In the United Kingdom, the presence of Japanese Knotweed has now led to reduction of property value and refusal to mortgage.
  • Yellow Flag Iris grows in water as dense thickets and blocks drainage.

Currently, there are more than 9 hectares of Japanese Knotweed on municipal land in the District of Squamish (based on 2010 data). Mapping shows that Japanese Knotweed and aforementioned species are spreading, and locations are increasing each year.


The Sea to Sky Invasive Species Council undertakes a control program for Japanese Knotweed (Fallopia japonica), in partnership with various landowners including the District of Squamish.

Learn more about the program

The District of Squamish works closely with the Sea to Sky Invasive Species Council, and contributes annually to the organization.

These funds are successfully leveraged by SSISC to obtain additional funding, and used to develop programs that both benefit our community and provide direct support to District of Squamish staff to manage invasive species.

Some of the programs include the Japanese Knotweed Pesticide Control Program, the Invasive-Free Certification Program, Rebate Program for Invasive Plant Control on Private Land, and Community Weed Pulls.

For more information:

Sea to Sky Invasive Species Council website

   Japanese Knotweed Treatment Program    


Invasive Plants & Soil Permits

The movement of soil that contains invasive plants, roots or seeds may require a Soil Permit. If you are unsure, please contact us by email or 604.815.5012.


Contact us: [email protected], 604.815.5012 or use the online customer service form.

Customer Service Form

Sea to Sky Invasive Species Council

The SSISC works to minimize the threat of invasive species that impact the environment, the economy and human health in the Sea to Sky Corridor.

Disclaimer: This content is a summary of the District’s Environmental Bylaws & Guidelines. It is not legal advice and does not provide an interpretation of the law. In the event of any conflict or difference between this webpage and the bylaws or guidelines, the bylaws or guidelines are correct and legal and must be followed.