PlaceDossier / BC places / Lakes

BC lake · 22 km² · Upper Shuswap watershed

Sugar Lake

Its median summer Secchi depth over 2012–2025 was 9.3 m, from 16 readings. Clearer than 85% of the 62 BC lakes with enough recent readings.

The readings

172 summer readings from open water on record from 1973 to 2025, at 1 sampling site.

Median since 2012Compared with BC lakes
Secchi depth9.3 m
2012–2025, 16 readings		Clearer than 85% of the 62 BC lakes with enough recent readings.
Total phosphorus2.5 µg/L
2012–2025, 16 readings		Lower than 95% of the 100 BC lakes with enough recent readings (lower is clearer).
Chlorophyll a1.1 µg/L
2012–2025, 19 readings		Lower than 76% of the 83 BC lakes with enough recent readings (lower is clearer).
Secchi depth how deep a black-and-white disc stays visible: deeper means clearer water
0510 19801990200020102020 1973: median 10.1 m from 1 reading1974: median 6.1 m from 2 readings1976: median 4.7 m from 2 readings1978: median 7.5 m from 2 readings1980: median 8.0 m from 3 readings1981: median 6.8 m from 2 readings1983: median 6.0 m from 1 reading1984: median 8.8 m from 2 readings1985: median 10 m from 1 reading1987: median 9.0 m from 1 reading1988: median 8.0 m from 1 reading1990: median 8.0 m from 1 reading1991: median 8.2 m from 2 readings1992: median 10 m from 1 reading1994: median 8.8 m from 1 reading1995: median 8.7 m from 1 reading1998: median 10.4 m from 1 reading1999: median 5.6 m from 1 reading2000: median 8.1 m from 1 reading2001: median 9.8 m from 1 reading2002: median 9.7 m from 2 readings2004: median 8.5 m from 1 reading2009: median 10.2 m from 2 readings2010: median 11.1 m from 1 reading2011: median 8.6 m from 1 reading2012: median 9.3 m from 1 reading2013: median 8.8 m from 1 reading2014: median 9.9 m from 1 reading2015: median 8.2 m from 1 reading2016: median 8.5 m from 1 reading2017: median 9.3 m from 1 reading2018: median 7.8 m from 2 readings2019: median 10.7 m from 1 reading2020: median 7.3 m from 1 reading2021: median 9.2 m from 1 reading2022: median 8.0 m from 1 reading2023: median 9.7 m from 2 readings2024: median 9.7 m from 1 reading2025: median 9.9 m from 1 readingm
Total phosphorus the nutrient that most often feeds algae in BC lakes
31030 19801990200020102020 1974: median 4.5 µg/L from 2 readings1976: median 5.5 µg/L from 2 readings1978: median 5.5 µg/L from 2 readings1980: median 7.0 µg/L from 2 readings1981: median 6.5 µg/L from 2 readings1983: median 8.0 µg/L from 1 reading1984: median 51 µg/L from 2 readings1985: median 4.0 µg/L from 3 readings1986: median 3.0 µg/L from 1 reading1987: median 7.0 µg/L from 1 reading1988: median 3.0 µg/L from 1 reading1989: median 3.0 µg/L from 1 reading1990: median 4.0 µg/L from 1 reading1991: median 3.0 µg/L from 1 reading1992: median 3.0 µg/L from 1 reading1993: median 3.0 µg/L from 3 readings1994: median 4.0 µg/L from 1 reading1996: median 9.0 µg/L from 1 reading1997: median 9.0 µg/L from 2 readings1998: median 3.0 µg/L from 1 reading1999: median 4.0 µg/L from 1 reading2000: median 7.0 µg/L from 1 reading2001: median 2.0 µg/L from 1 reading2002: median 2.0 µg/L from 2 readings2004: median 2.0 µg/L from 1 reading2005: median 2.0 µg/L from 1 reading2006: median 3.0 µg/L from 1 reading2008: median 3.0 µg/L from 1 reading2009: median 2.0 µg/L from 2 readings2010: median 2.0 µg/L from 1 reading2011: median 2.0 µg/L from 1 reading2012: median 3.0 µg/L from 1 reading2013: median 2.9 µg/L from 1 reading2014: median 2.0 µg/L from 1 reading2015: median 4.0 µg/L from 1 reading2016: median 2.0 µg/L from 1 reading2017: median 2.0 µg/L from 1 reading2018: median 2.6 µg/L from 2 readings2019: median 2.0 µg/L from 1 reading2020: median 2.0 µg/L from 1 reading2021: median 4.4 µg/L from 1 reading2022: median 3.7 µg/L from 1 reading2023: median 4.1 µg/L from 2 readings2024: median 2.0 µg/L from 1 reading2025: median 2.0 µg/L from 1 readingµg/L
Chlorophyll a the green pigment in algae: a direct measure of how much is growing
0.313 19801990200020102020 1976: median 0.9 µg/L from 3 readings1978: median 1.1 µg/L from 2 readings1980: median 1.0 µg/L from 2 readings1981: median 0.9 µg/L from 2 readings1983: median 1.7 µg/L from 1 reading1984: median 0.9 µg/L from 2 readings1987: median 0.6 µg/L from 1 reading1988: median 1.0 µg/L from 1 reading1989: median 2.8 µg/L from 1 reading1990: median 1.2 µg/L from 1 reading1991: median 1.2 µg/L from 1 reading1992: median 2.3 µg/L from 1 reading1993: median 1.7 µg/L from 2 readings1994: median 2.1 µg/L from 1 reading1996: median 0.9 µg/L from 2 readings1997: median 3.2 µg/L from 4 readings1998: median 0.2 µg/L from 1 reading1999: median 1.1 µg/L from 1 reading2000: median 2.1 µg/L from 1 reading2001: median 1.1 µg/L from 1 reading2002: median 2.0 µg/L from 2 readings2004: median 2.5 µg/L from 1 reading2005: median 5.2 µg/L from 1 reading2006: median 1.7 µg/L from 2 readings2008: median 1.2 µg/L from 1 reading2009: median 1.1 µg/L from 2 readings2010: median 0.5 µg/L from 1 reading2011: median 1.9 µg/L from 1 reading2012: median 1.8 µg/L from 1 reading2013: median 1.4 µg/L from 1 reading2014: median 1.3 µg/L from 1 reading2015: median 1.7 µg/L from 4 readings2016: median 1.5 µg/L from 1 reading2017: median 1.4 µg/L from 1 reading2018: median 0.6 µg/L from 2 readings2019: median 1.0 µg/L from 1 reading2020: median 0.6 µg/L from 1 reading2021: median 0.7 µg/L from 1 reading2022: median 0.5 µg/L from 1 reading2023: median 0.8 µg/L from 2 readings2024: median 0.8 µg/L from 1 reading2025: median 0.4 µg/L from 1 readingµg/L

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

Reads as oligotrophic (few nutrients, little algae, usually clear).

IndexClass
From secchi depth (9.3 m, 2012–2025)28oligotrophic
From total phosphorus (2.5 µg/L, 2012–2025)17oligotrophic
From chlorophyll a (1.1 µg/L, 2012–2025)31oligotrophic

Inferred by us, not a provincial classification. The index was built for summer readings from the middle of a lake; ours mix sites and months, so treat the class as a rough guide.

How we worked this out

Carlson's trophic state index (Carlson 1977, Limnology and Oceanography 22:361) turns each median into a score: 60 − 14.41 ln(Secchi m), 14.42 ln(phosphorus µg/L) + 4.15, 9.81 ln(chlorophyll µg/L) + 30.6. Classes after Carlson and Simpson (1996): under 40 oligotrophic, 40 to 50 mesotrophic, 50 to 70 eutrophic, 70 and over hypereutrophic.

Year by year

YearSecchi depthTotal phosphorusChlorophyll a
20259.9 m (1)2.0 µg/L (1)0.4 µg/L (1)
20249.7 m (1)2.0 µg/L (1)0.8 µg/L (1)
20239.7 m (2)4.1 µg/L (2)0.8 µg/L (2)
20228.0 m (1)3.7 µg/L (1)0.5 µg/L (1)
20219.2 m (1)4.4 µg/L (1)0.7 µg/L (1)
20207.3 m (1)2.0 µg/L (1)0.6 µg/L (1)
201910.7 m (1)2.0 µg/L (1)1.0 µg/L (1)
20187.8 m (2)2.6 µg/L (2)0.6 µg/L (2)
20179.3 m (1)2.0 µg/L (1)1.4 µg/L (1)
20168.5 m (1)2.0 µg/L (1)1.5 µg/L (1)
20158.2 m (1)4.0 µg/L (1)1.7 µg/L (4)
20149.9 m (1)2.0 µg/L (1)1.3 µg/L (1)
20138.8 m (1)2.9 µg/L (1)1.4 µg/L (1)
20129.3 m (1)3.0 µg/L (1)1.8 µg/L (1)
20118.6 m (1)2.0 µg/L (1)1.9 µg/L (1)
201011.1 m (1)2.0 µg/L (1)0.5 µg/L (1)
200910.2 m (2)2.0 µg/L (2)1.1 µg/L (2)
2008–3.0 µg/L (1)1.2 µg/L (1)
2006–3.0 µg/L (1)1.7 µg/L (2)
2005–2.0 µg/L (1)5.2 µg/L (1)
20048.5 m (1)2.0 µg/L (1)2.5 µg/L (1)
20029.7 m (2)2.0 µg/L (2)2.0 µg/L (2)
20019.8 m (1)2.0 µg/L (1)1.1 µg/L (1)
20008.1 m (1)7.0 µg/L (1)2.1 µg/L (1)
19995.6 m (1)4.0 µg/L (1)1.1 µg/L (1)
199810.4 m (1)3.0 µg/L (1)0.2 µg/L (1)
1997–9.0 µg/L (2)3.2 µg/L (4)
1996–9.0 µg/L (1)0.9 µg/L (2)
19958.7 m (1)––
19948.8 m (1)4.0 µg/L (1)2.1 µg/L (1)
1993–3.0 µg/L (3)1.7 µg/L (2)
199210 m (1)3.0 µg/L (1)2.3 µg/L (1)
19918.2 m (2)3.0 µg/L (1)1.2 µg/L (1)
19908.0 m (1)4.0 µg/L (1)1.2 µg/L (1)
1989–3.0 µg/L (1)2.8 µg/L (1)
19888.0 m (1)3.0 µg/L (1)1.0 µg/L (1)
19879.0 m (1)7.0 µg/L (1)0.6 µg/L (1)
1986–3.0 µg/L (1)–
198510 m (1)4.0 µg/L (3)–
19848.8 m (2)51 µg/L (2)0.9 µg/L (2)
19836.0 m (1)8.0 µg/L (1)1.7 µg/L (1)
19816.8 m (2)6.5 µg/L (2)0.9 µg/L (2)
19808.0 m (3)7.0 µg/L (2)1.0 µg/L (2)
19787.5 m (2)5.5 µg/L (2)1.1 µg/L (2)
19764.7 m (2)5.5 µg/L (2)0.9 µg/L (3)
19746.1 m (2)4.5 µg/L (2)–
197310.1 m (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

  • 0500119 Sitkum Creek 172 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.