Stormwater Management Planning

Managing stormwater isn't just about pipes and ponds - it's about planning for the long term.

Nanaimo's stormwater system is one part of a much larger network of City assets, and all of them compete for the same limited funding. Asset management helps us understand the condition of our infrastructure, set priorities, and make informed - and difficult - decisions about when and where investments are most needed.

Even with good planning tools, not every project can happen right away. The City looks at risk, cost, timing, and community benefit to determine what work should be done first and what can be scheduled for future years.

What Is Asset Management?

Asset management helps the City answer three key questions:

• What do we own? (Inventory of pipes, ponds, and other assets)
• What condition is it in? (Inspections and performance indicators)
• What do we need to do next? (Prioritizing repairs and investments)

These insights help us balance stormwater needs alongside other essential assets like roads, recreational facilities, and parks, and ensure limited funds are directed where they will have the most benefit.

The Long-Term Cost of Stormwater Infrastructure

Asset management helps the City understand not just what infrastructure we have today, but what it will take to maintain, replace and upgrade it over time.

For stormwater, this is a long-term challenge. Based on asset management planning, Nanaimo's stormwater infrastructure has an estimated replacement value of more than $947 million (2021 dollars).
Many of these assets are designed to last between 30 and 100 years, which means renewal and replacement must be planned decades in advance. Stormwater capital work (2026-2030) is estimated at a range of $4 - $6  million per year which is less than long term annual replacement needs.

The City must carefully sequence upgrades over many years. Not every project can happen at once, so some work must be postponed. This requires weighing risks, benefits, and competing needs across all City assets to decide what moves forward now and what must wait.

How We Decide Where to Invest

Over the next five years, the City plans to invest about $4.1 million per year in high-priority stormwater projects. These upgrades reduce risk, improve resilience, and help us prepare for more intense storms.

To help guide these decisions, the City develops Stormwater Master Plans for catchments like Eagle Point, Cottle Creek, Departure Bay, Catstream, and Wexford Creek. Catchments are prioritized for Master Plans and subsequent upgrades based on three key factors:

• Areas with a history of flooding or erosion come first.
• Neighbourhoods under development are prioritized to prevent future problems.
• Older infrastructure most likely to fail is scheduled for upgrades.

These plans use modelling to identify capacity constraints and prioritize improvements in flood-prone areas and growing neighbourhoods. These plans help to ensure the system can handle future growth and climate impacts.

Stormwater Requirements for New Developments

New developments must meet the stormwater standards outlined in the most current Manual of Engineering Standards and Specifications (MoESS).

These requirements help ensure growth doesn't increase flooding risk or harm waterways. They  help manage runoff, protect sensitive ecosystems, and support climate resiliience.

Resources for Developers:

• MoESS Full Specifications
• Green Initiatives for sustainability programs and low-impact development options that compliment stormwater standards.