Stormwater Management

The City is developing Integrated Stormwater Management Plans (ISMPs) for the north shore area and Inlet Centre neighbourhood of Port Moody.

The ISMPs, mandated for all member municipalities by Metro Vancouver’s Integrated Liquid Waste Resource Management Plan, will be developed in three phases, beginning with field work and information collection. Stakeholder and public engagement is the second phase and will help us identify and prioritize our stormwater management values and goals. The third and final phase will be drafting and implementing the ISMPs.

There are five designated study areas that require ISMPs in Port Moody. Two have been completed (Chines and Stoney Creek) and two are underway. Next will be an ISMP for the Glenayre and College Park study area.

Stormwater

Stormwater is the water from rain or melting snow that is either absorbed into the ground or flows over the ground, collects in watercourses and ponds, and is directed into the municipal storm sewer system. We collect stormwater from roads, homes, and businesses in our storm sewer system and safely discharge it to the Burrard Inlet. We are responsible for managing the quantity and rate of stormwater runoff, as well as the quality before discharge.

It is important to reduce the amount of stormwater runoff as excessive amounts can cause flooding and erosion that degrades water quality in watercourses such as creeks, streams, ditches, etc. Erosion is a significant concern for property owners as it can lead to slope failure or slides which can damage structures, trees, and landscaping on private property. It's also a significant concern from an environmental perspective. As stormwater passes over roads, parking lots, driveways, and other paved surfaces, it picks up pollutants such as oils, pesticides, solvents, and other chemicals. These pollutants are then carried into local bodies of water where they can damage or destroy fish and wildlife habitat.

Integrated Stormwater Management Plan (ISMP)

An ISMP identifies actions to maintain and enhance the overall health of a watershed in response to urban development. The plan integrates and balances stormwater management with environmental protection and land use planning to direct future activities such as stormwater utility improvements, bank stabilization, and watercourse restoration. ISMPs can help inform infrastructure, community plans, and other municipal projects.

Study area

This project focuses on two distinct study areas — marked in yellow and green on the map below — which together cover the majority of the urban north shore area as well as east of the Burrard Inlet to the Coquitlam border. Each study area will have a unique ISMP.

Key Issues

Increased urban development alters the natural water cycle and can impact watershed health. Hard surfaces, such as roofs and roads, increase runoff and stormwater flows, and often lead to more pollution in receiving water bodies. In addition, according to climate change models, we can expect future rainfall events to last longer and be more intense – this will increase the risk of negative effects on watershed health.

Our ISMPs will help to reduce the impact of existing and potential issues such as:

• poor stream water quality – can negatively affect aquatic life.
  
  
• low summer base flows – can reduce habitat for fish and other aquatic life.
  
  
• extreme high flows – can cause streambank erosion, landslides, and debris flows that negatively affect water quality and habitat, as well as create increased risk of flooding, property damage, and safety issues.
  
  
• increase capital costs - without the appropriate management of stormwater runoff, high flows can lead to large capital investments to increase the size of storm sewer pipes, construct stormwater storage facilities, or upgrade overland routes.