Urban Development

Salmon in the City

Entire salmon streams have been lost to urban growth. Where they still return to cities, salmon prove their resilience – but they aren’t invincible.

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The human population in B.C. has grown almost ten-fold over the past century,^† and the urbanization that followed has reshaped the landscape.

Forests and wetlands have been replaced with roads, buildings, and urban infrastructure in some of the most historically productive salmon watersheds. These changes alter how water moves across the landscape and what it carries with it, often reducing the quality and availability of salmon habitat. Streams and rivers have been straightened, confined, or routed through pipes, and their links to floodplains, wetlands, and estuaries are cut off.

Urban runoff floods streams quickly, and can carry toxic contaminants that can harm salmon or their ecosystems. And yet salmon persist in major cities, navigating the province’s urban heartland – a display of resilience that should not be mistaken for invincibility.

The streams beneath our cities

What is now the city of Vancouver was once home to more than 50 streams, most them likely used by salmon at one point in time^†.

As part of colonial settlement, almost all streams were eventually confined to pipes and buried beneath pavement. Though invisible, the streams are often still there, transporting rainwater under some of the city’s busiest streets. In fact, under Vancouver’s Main Street is Brewery Creek, the water source that once drew some of the city’s first breweries to open along its banks^†.

Underground, these streams can no longer support salmon. Across the lower Fraser Valley alone, at least 117 streams have been lost since modern day record-keeping began^†, while many others have been heavily altered by culverts, dikes, storm drains, and flood-control infrastructure designed to contain and redirect water. Similar “lost streams” exist beneath cities across BC, where urban development has buried waterways under roads, neighbourhoods, and industrial areas. Although many of these streams still flow underground, they no longer provide the cool, connected habitat salmon need to migrate, spawn, and rear.

Map of Vancouver's historical stream network, far denser than today, before most streams were buried — Drag to compare Vancouver’s streams today with the network that once flowed before most were buried beneath the city. Tap “View larger” to zoom in.

Map of Vancouver's streams today, with most historical streams now buried beneath the city — Drag to compare Vancouver’s streams today with the network that once flowed before most were buried beneath the city. Tap “View larger” to zoom in.

At least 117 streams had been lost in the lower Fraser Valley as of 1998 – today’s number is likely much higher.^† More still have been altered by culverts, dikes, storm drains, and flood-control infrastructure, which can make these habitats unusable for salmon.

Daylighting streams to give salmon a second chance

In recent years, efforts to uncover or “daylight” buried streams have gained momentum in many urban areas.

By restoring natural stream banks and reopening sections of waterways that were previously buried underground, communities can gradually reconnect salmon habitat and revive ecological functions that had been lost to urban development. These projects are often complex and long-term, unfolding over decades as opportunities for restoration emerge.

One notable example is Still Creek, which flows through industrial and urban areas of Burnaby and East Vancouver. After years of restoration and daylighting work aimed at improving habitat and reconnecting the stream, chum salmon returned to spawn in Still Creek in 2012 – the first recorded return in decades – becoming a celebrated symbol of urban ecological recovery^†. Similar projects are underway elsewhere in B.C. through partnerships among municipalities, community groups, and conservation organizations.

The Pacific Salmon Foundation’s community grants program, for example, has supported restoration and daylighting efforts along Bowker Creek in Victoria, helping reconnect fragmented habitat and bring salmon back to urban landscapes^†.

A salmon stream sign beside an urban waterway — FPOA reminder of the salmon streams woven through our neighbourhoods. Braela Kwan.

Example

When streams cross roads

Culverts that run under roads, railways, and other infrastructure connect waterways, but are often unsuccessful at connecting salmon habitats – they are often too narrow, too steep, or flow too quickly for salmon to navigate. Fortunately, simple changes can make a big impact: wider culverts embedded into the streambed, and engineered to better mimic natural stream conditions, can turn these barriers into fish-friendly passages that help salmon reach more of their habitat^†.

A fish-friendly culvert embedded into the streambed with water flowing through — A non-fish-friendly culvert (left) versus a fish-friendly culvert (right), embedded into the streambed. Drag to compare.

A non-fish-friendly culvert, raised above and disconnected from the streambed — A non-fish-friendly culvert (left) versus a fish-friendly culvert (right), embedded into the streambed. Drag to compare.

Across British Columbia alone, there are over 170,000 culverts that impede fish passage.^†

Urban Stream Syndrome

In urbanized areas where salmon still persist, streams and rivers often behave very differently from those in intact natural watersheds – a pattern sometimes referred to as urban stream syndrome^†.

Urban streams tend to be flashy – water levels rise and fall rapidly during rainstorms or snowmelt. In natural watersheds, forests, wetlands, and soils absorb and slowly release water. In cities, however, pavement, rooftops, and storm drains quickly funnel water into streams and rivers. These sudden high flows can erode streambanks, wash away spawning gravel, and remove fallen logs that create the deep pools juvenile salmon rely on for shelter. In severe cases, strong flood events can even scour developing salmon eggs from the streambed. During droughts, urban streams often become unusually warm and shallow, especially where streamside trees and vegetation have been removed^†.

Exposed riverbed and stranded debris during the 2023 Tranquille River drought — FPOTranquille River drought, 2023. Peter Olsen.

A storm drain marked with a painted yellow fish symbol — Urban storm drains funnel water quickly into waterways. The yellow fish is a reminder that they lead to fish habitat. Photo from Morrison Creek Streamkeepers.

Polluted runoff runs into urban streams

Urban runoff also carries a wide range of contaminants into salmon habitat. Rainwater flowing across roads, parking lots, lawns, and industrial areas can pick up oil, heavy metals, pesticides, tire chemicals, and household pollutants before entering storm drains that often discharge directly into local waterways without treatment. Increasing public awareness about what enters storm drains has become an important part of urban salmon stewardship. Community initiatives such as storm drain marking programs – where yellow fish symbols are painted beside drains to remind people that “only rain goes down the drain” – help connect people to the hidden waterways beneath their neighbourhoods and encourage everyday actions that protect salmon habitat.

The toxic tire chemical killing urban salmon

Starting in the 1990s, scientists and citizens noticed that Coho in urban streams were dying after major rainstorms, before they could spawn.

It was decades before scientists could isolate the chemical and prove that 6PPD-Q, a derivative of a chemical added to tires to extend their lifespan, was causing the Coho deaths. As tires wear, 6PPD-Q is deposited on roads and washed into nearby waterways during rainfall, where it can reach levels that are deadly to adult salmon^†. There are still unanswered questions, including why it seems to only affect Coho salmon – which is why PSF has urged government to investigate 6PPD-Q and work toward regulations that would ensure levels in road runoff are safe for salmon.

6PPD-Q (Tire-wear chemical) makes its way into urban streams and kills coho.

How 6PPD-Q reaches salmon streams. Adapted for State of Salmon from psf.ca/work/climate/tire-wear-toxin-6ppd-q. Swipe · tap to enlarge

Straightened and
armoured shores

To control flooding, cities straighten banks, armour shorelines, and confine waterways and the fish within them. Over the past two centuries, flood control infrastructure – like dikes, levees, and floodwalls – expanded across urban and industrial landscapes. As climate change continues driving sea level rise and unpredictable flooding, the pressure to build and expand this infrastructure is expected to grow – but there are consequences for salmon, and there may be better alternatives.

Straightened rivers in the Okanagan

Channelizing rivers and streams – straightening and reinforcing their banks – is a common way that cities control flows and allow development closer to the waterways, but there are costs. These simplified channels make poor habitats for salmon, who thrive in complex river systems with a variety of connected habitats, like deep pools, shallow side channels, seasonally flooded wetlands, gravel spawning beds, and slow-moving rearing areas. This habitat complexity supports the remarkable diversity of Pacific salmon species and life histories.

When cities are built around rivers, these habitats get developed, leaving only a single, uniform main channel – and salmon diversity can be lost as a result. A large portion of the Okanagan River was channelized in the 1950s, and today, opportunities to restore it back to its natural state are constrained by the cities that grew around it.

The Okanagan River at Penticton today, channelized into a straight course — The Okanagan River at Penticton, BC before and after it was channelized in the 1950s. The remains of meandering river channels are still visible today, but are not connected to the main channel.

The Okanagan River at Penticton in a historical aerial view — The Okanagan River at Penticton, BC before and after it was channelized in the 1950s. The remains of meandering river channels are still visible today, but are not connected to the main channel.

Riprap and seawall armouring along an eastern Vancouver Island shoreline — Riprap and seawall hardening a shoreline on eastern Vancouver Island. Pacific Salmon Foundation, Resilient Coasts for Salmon.

Armoured shorelines on Vancouver Island

Scientists and city planners are starting to recognize that intact wetlands, estuaries, and tidal habitats provide even better, and cheaper flood protection in the long term than concrete barriers and other hard infrastructure alone.

These natural systems absorb floodwaters while providing habitat for growing salmon and other wildlife – a true win-win. A recent PSF project mapped shoreline armouring along eastern Vancouver Island, identifying where more natural shoreline solutions could replace seawalls and riprap. Natural coastal habitats were then restored at select locations, and forage fish – important prey for salmon – quickly returned to spawn in some of those new habitats^†.

In East Vancouver Island communities, up to 69% of the shoreline has already been modified with structures like breakwaters, boardwalks, and seawalls (PSF Resilient Coasts for Salmon Map).

Green infrastructure benefits us all

As communities grow, investing in green infrastructure – strategically placed natural spaces that serve purposes like flood control – is a chance to work with nature instead of against it. Green infrastructure systems can be as extensive as constructed wetlands that protect entire communities from flooding, but often are much smaller scale, and include rain gardens, bioswales, and pervious pavement. These slow and reduce the amount of water entering storm drains, moving cities back toward the natural water cycles that existed there before urbanization^†. There are also benefits to water quality – rain gardens that capture and filter runoff can prevent over 90% of 6PPD-Q from entering waterways^†.

The city of Delta now has over 40 rain gardens, which are also used to teach the importance of watershed management through school partnerships^†. Making space for natural ecosystems in our future cities, and bringing back ecosystem functions where possible, will confer benefits beyond salmon – to people, wildlife, and future generations alike.

Illustration of a home using nature-based solutions: rain gardens, a naturalized shoreline, trees and permeable ground that slow and filter runoff

A park with rain-garden plantings, autumn trees, and apartment buildings above a green lawn – an example of urban green infrastructure

The streams beneath our cities may be altered, but their story is not finished. With the right choices, urban landscapes can once again become places where salmon and people flourish.