PlaceDossier / BC places / Lakes
BC lake · 6 km² · Chilliwack River watershed
Cultus Lake
Too few readings to judge this lake: 85 summer readings from open water between 1972 and 2024, 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.
The readings
85 summer readings from open water on record from 1972 to 2024, at 1 sampling site.
| Median since 2012 | Compared with BC lakes | |
|---|---|---|
| Secchi depth | Too few readings to judge 8 readings since 2012 | Too few readings to compare (8 readings since 2012). |
| Total phosphorus | Too few readings to judge 8 readings since 2012 | Too few readings to compare (8 readings since 2012). |
| Chlorophyll a | Too few readings to judge 8 readings since 2012 | Too few readings to compare (8 readings since 2012). |
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 (8 readings since 2012); total phosphorus (8 readings since 2012); chlorophyll a (8 readings since 2012).
Year by year
| Year | Secchi depth | Total phosphorus | Chlorophyll a |
|---|---|---|---|
| 2024 | 9.0 m (1) | 3.4 µg/L (1) | 0.5 µg/L (1) |
| 2023 | 13.3 m (1) | 2.6 µg/L (1) | 0.3 µg/L (1) |
| 2022 | 8.2 m (1) | 3.3 µg/L (1) | 1.3 µg/L (1) |
| 2021 | 8.3 m (1) | 3.9 µg/L (1) | 1.2 µg/L (1) |
| 2020 | 11.3 m (1) | 3.1 µg/L (1) | 1.2 µg/L (1) |
| 2019 | 6.8 m (1) | 3.3 µg/L (1) | 0.8 µg/L (1) |
| 2018 | 8.4 m (2) | 3.5 µg/L (2) | 2.0 µg/L (2) |
| 1986 | – | 3.0 µg/L (1) | – |
| 1982 | – | – | 3.2 µg/L (2) |
| 1979 | 11.1 m (8) | 4.0 µg/L (12) | 0.9 µg/L (12) |
| 1978 | – | 4.5 µg/L (6) | – |
| 1977 | 7.5 m (2) | 3.0 µg/L (1) | 2.1 µg/L (1) |
| 1976 | 9.1 m (1) | 3.0 µg/L (2) | 1.4 µg/L (2) |
| 1975 | 7.6 m (3) | 4.0 µg/L (3) | – |
| 1974 | – | 4.0 µg/L (1) | – |
| 1973 | 6.1 m (1) | 5.0 µg/L (1) | – |
| 1972 | 7.0 m (1) | 3.0 µg/L (1) | – |
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
- 0300037 At centre 85 readings
Left out: 32 readings at 3 sites whose names put them away from the open lake
- E207095 North beach 11 readings; on the shore
- E207096 Middle beach 11 readings; on the shore
- E207098 South beach 10 readings; on the shore
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 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.