PlaceDossier / BC places / Lakes
BC lake · 12 km² · Francois Lake watershed
Decker Lake
Too few readings to judge this lake: 29 summer readings from open water between 1990 and 2015, 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
29 summer readings from open water on record from 1990 to 2015, at 2 sampling sites.
| Median since 2012 | Compared with BC lakes | |
|---|---|---|
| Total phosphorus | Too few readings to judge 2 readings since 2012, in 1 year | Too few readings to compare (2 readings since 2012, in 1 year). |
| Chlorophyll a | Too few readings to judge 2 readings since 2012, in 1 year | Too few readings to compare (2 readings since 2012, in 1 year). |
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): total phosphorus (2 readings since 2012, in 1 year); chlorophyll a (2 readings since 2012, in 1 year).
Year by year
| Year | Total phosphorus | Chlorophyll a |
|---|---|---|
| 2015 | 24 µg/L (2) | 4.3 µg/L (2) |
| 2005 | 26 µg/L (2) | – |
| 2003 | 22 µg/L (4) | – |
| 2002 | 17 µg/L (4) | 10 µg/L (4) |
| 1993 | 27 µg/L (3) | – |
| 1990 | 20 µg/L (8) | – |
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
- E208097 Across from Town site 26 readings
- 0400368 South near outlet 3 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 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.