RESILIENT COASTS FOR SALMON SPOTLIGHT COMMUNITIES
Colwood
Colwood is a coastal city located on the southern tip of Vancouver Island. It is home to the Esquimalt Lagoon, an important estuary and federal Migratory Bird Sanctuary. The unique physical processes within the lagoon have created a biologically rich area that is particularly sensitive to human disturbance and environmental changes. Beyond the lagoon, Colwood’s coastline is also influenced by recreational and residential development, such as marinas and shoreline hardening.
For the purposes of the Resilient Coasts for Salmon initiative, the Colwood study area covers 15 km of marine shoreline along the Strait of Juan de Fuca, with data derived from imagery collected up to 2025.
Colwood lies within the ancestral lands of Teechamista and the Lək̓ʷəŋən (Lekwungen)-speaking people of the xʷsepsəm (Kosapsum) and Songhees First Nations.
Key Findings
Shoreline Modifications
Man-made structures like seawalls and riprap, often built to protect shoreline infrastructure, can actually exacerbate erosion by redirecting wave energy to nearby areas. These modifications also remove key intertidal habitats and food sources essential for the growth and survival of juvenile salmon and forage fish. By stripping away the natural complexity of coastal ecosystems, shoreline modifications reduce their capacity to support biodiversity and adapt to rising sea levels.
Extent of shoreline modification
As of 2022, approximately 35 km of Colwood’s shoreline has been modified, while 11.7 km remains natural. This indicates that roughly 23% of the community’s shoreline is classified as modified – Figure 1.
Figure 1. Coastal modifications (shown in blue) with the extent of data collection outlined by red dashes.
Most common shoreline modification types
The most common modification types were other (71.4%), riprap (20%), and fill (6.8%) – see Figure 2. The other category indicates that the feature did not fit in to any modification type category. See the comments section for each feature for details about the feature noted by the recorder. For the Colwood shoreline, features marked as ‘other’ included roads and parking lots, vehicle and pedestrian bridge supports, and docks and buildings associated with Canadian Armed Forces.
Figure 2. The percentage of modified shoreline by modification type.
Most common materials used in shoreline modifications
The materials most commonly used for shoreline modification were rock (47.1%), unknown/undefined (38.3%), and concrete (14.1%) – see Table 1. The unknown/undefined category indicates that the recorder was not able to determine the material that was used, due to issues with image clarity or obstruction, or in cases when a mix of materials were used.
Table 1. The percentage of modifications, based on the type of material used in the modifications.
| Material | Percentage of Modifications |
| Rock | 47.1 |
| Unknown/Undefined | 38.3 |
| Concrete | 14.1 |
| Wood/Cresote Wood | 0.2 |
| Masonry | 0.2 |
Overwater Structures
Overwater structures, like docks and piers, cast heavy shade that degrades nearshore habitat. Juvenile salmon avoid these shaded areas, which alters their natural foraging and migration patterns by forcing them into deeper waters. There, they expend more energy and face greater predation risk. The reduced light also limits the growth of essential habitats like eelgrass and algae, along with the diverse communities they support.
Number of overwater structures total and by type
As of 2025, the total number of overwater structures in Colwood is 15, consisting of industrial overwater structures (7), residential docks (3), individual or groupings of creosote pilings (3), and piers, boardwalks or wharfs (2) – see Figure 3.
Figure 3. The extent of overwater structures within Colwood.
Log Accumulation
While logs are a natural part of coastal ecosystems, the escape of modified logs from log booms is leading to excessive accumulation. These logs can scour beaches, altering sediment composition and smothering nearshore vegetation. Unlike natural logs, modified logs are stripped of root balls and branches, making them unstable and prone to rolling across critical habitats that juvenile salmon and forage fish rely on for growth, food, and shelter.
For the results below, about 48% (7.3 km) of the shoreline was not digitized for log accumulation due to lack of shoreline imagery.
Extent of log accumulation
Of the total shoreline, 4.6% (0.7 km) was found to have an extreme (>89%) accumulation of logs, with another 20% (3 km) with high accumulations (50 to 89% coverage), and 8.4% (1.3 km) having moderate levels (20% to 49%) of the beach covered by logs – see Table 2. It should be noted that the moderate log accumulation category also represents a significant coverage of logs – whereby 20-49% log coverage on a given beach could negatively impact shoreline habitat.
Table 2. The length of shoreline (in percentage and metres) by category of log accumulation.
| Log Accumulation | Percentage of Shoreline | Metres |
| Extreme (>89%) | 4.6 | 698 |
| High (50 to 89%) | 19.5 | 2,975 |
| Moderate (20 to 49%) | 8.4 | 1,272 |
| Low/None (<20%) | 19.4 | 2,958 |
| Unknown | 48.1 | 7,322 |
Mobility of Logs
There were only mobile logs as part of log accumulation on 21.9% (3.3 km) of the shoreline, and another 29% (4.4 km) of the shoreline had both mobile and anchored logs.
To access and download the Resilient Coasts for Salmon layers for Colwood,click here.