PlaceDossier / BC places / Lakes
BC lake · 8.9 ha · Victoria watershed
Swan Lake
Too few readings to judge this lake: 112 summer readings from open water between 1987 and 2026, and we need at least 10 summer readings from open water, spread over at least 3 different years, since 2012 before we summarise or compare it. The readings are below. It lies in Saanich.
The readings
112 summer readings from open water on record from 1987 to 2026, at 1 sampling site.
| Median since 2012 | Compared with BC lakes | |
|---|---|---|
| Secchi depth | Too few readings to judge 12 readings since 2012, in 1 year | Too few readings to compare (12 readings since 2012, in 1 year). |
| Total phosphorus | Too few readings to judge 45 readings since 2012, in 2 years | Too few readings to compare (45 readings since 2012, in 2 years). |
| Chlorophyll a | Too few readings to judge 22 readings since 2012, in 2 years | Too few readings to compare (22 readings since 2012, in 2 years). |
Median each year (bigger dot, more readings)Middle half of BC lakesBC median
Source: BC Environmental Monitoring Data System (EnMoDS) results, Environmental Monitoring and Analysis Branch, Province of BC, records to September 19, 2026 (Open Government Licence – British Columbia); lake outlines and names: Freshwater Atlas lakes, Province of BC (Open Government Licence – British Columbia). Summaries by PlaceDossier.
Nutrient level Inferred
Unclear: too few readings to judge this lake's nutrient level.
Left out for too few recent readings (we need at least 10 summer readings from open water, spread over at least 3 different years, since 2012): secchi depth (12 readings since 2012, in 1 year); total phosphorus (45 readings since 2012, in 2 years); chlorophyll a (22 readings since 2012, in 2 years).
Year by year
| Year | Secchi depth | Total phosphorus | Chlorophyll a |
|---|---|---|---|
| 2026 | – | 507 µg/L (20) | 20 µg/L (10) |
| 2025 | 1.0 m (12) | 407 µg/L (25) | 33 µg/L (12) |
| 2002 | – | 203 µg/L (4) | – |
| 2001 | – | 251 µg/L (5) | – |
| 1988 | – | 1,200 µg/L (18) | 13 µg/L (4) |
| 1987 | – | 411 µg/L (2) | – |
Median of each year's May to October readings; the number of readings is in brackets.
Source: BC Environmental Monitoring Data System (EnMoDS) results, Environmental Monitoring and Analysis Branch, Province of BC, records to September 19, 2026 (Open Government Licence – British Columbia); lake outlines and names: Freshwater Atlas lakes, Province of BC (Open Government Licence – British Columbia). Summaries by PlaceDossier.
Where it was sampled
- E207364 Deep station 112 readings
Site names are tidied from the provincial records; the IDs find each site's full record there.
What this record doesn't cover
Algae bloom reports and invasive mussel checks aren't in this record: the province's Algae Watch map and mussel monitoring aren't published as open data. For swimming, check the regional health authority's beach advisories; for blooms and mussels, ask the province's regional environment office or the local lake association.
Readings are from the province's monitoring database: samples taken by provincial staff, volunteer lake monitors, and companies and local governments that sample under their permits. We keep the ice-free season (May to October), and for phosphorus and chlorophyll only samples from the top 5 m. We leave out sites whose names put them at a water intake, a sewage or industrial outfall, a mine, or a permit holder's works or the water receiving its discharge, or on the shore (a beach, dock or boat launch): water there can differ a lot from the open lake. Each year's figure is the median of that year's readings. We give a lake a summary, a comparison with other lakes and a nutrient level only when it has at least 10 summer readings from open water, spread over at least 3 different years, since 2012; the summary is the median of those readings. With fewer, or only older ones, we show the readings and say there are too few to judge the lake. A reading below the lab's detection limit counts at that limit. One site can be a bay rather than the open lake, so a lake's figures can differ from one end to the other.
Water quality changes with the season, the weather and the part of the lake. These are past readings, not a test of the water today: before you buy, ask the local government and the lake association what's known, and test a drinking-water intake yourself.