The lake is fed by a 12 km^2 watershed that consists of a mixture of agriculture, residential housing, and commercial areas, with impervious surfaces covering 25% of the watershed. Swan Lake in turn flows into Colquitz Creek and subsequently into Portage Inlet, a marine ecosystem connected to Victoria Harbour.
Since the mid-1800s, the lands adjacent to Swan Lake have been cleared and cultivated, and for almost 50 years the lake was used as a dumping ground for winery waste and sewage. These practices have stopped, but the lake is now subject to pollution in the form of runoff from increasing urbanization and agricultural areas. The lake suffers from, among other things, the loss of its native fresh-water fish population, poor water quality, low oxygen and invasive species. Therefore, the Swan Lake Christmas Hill Nature Sanctuary Society is developing a habitat management plan to prioritize and guide long-term restoration over the next 10-15 years. Despite the constraints, the Nature Sanctuary is an accessible green space that showcases the importance and value of urban ecosystem and provides ideal opportunities for teaching and learning about restoration, conservation and biodiversity monitoring.
At the watershed scale, improved best management practices are needed to reduce peak flows and pollution flowing into the streams and lake.
Ongoing restoration projects include:
- Invasive species removal
- Planting native species
- Bird habitat improvements
Ecological restoration activities have been occurring on the Hill for over 25 years. A Management Plan has been developed to address both the social and ecological aspects of this important parkland. Christmas Hill is almost completely surrounded by residential housing. Although there is currently very little public parking for the Hill, greater numbers of people will visit the Hill due to continued residential densification in the area. Moreover, the likelihood that people will use or treat the Hill in inappropriate ways, from off-trail use to vandalism, will continue to grow and remains a principal threat to the ongoing ecological health of the Hill.
Ongoing Restoration projects include:
- Removal of invasive species, including certain shrubs and trees
- Reintroduction of native species
- Trail construction which prevents foot traffic in sensitive areas
Past Projects at Swan Lake Christmas Hill Nature Sanctuary: