PlaceDossier / BC places / Lakes

BC lake · 20 km² · Okanagan River watershed

Skaha Lake

Its median summer Secchi depth over 2016–2025 was 6.2 m, from 30 readings. Clearer than 68% of the 122 BC lakes with at least 5 readings.

The readings

991 summer readings on record from 1973 to 2026, at 11 sampling sites.

Median, latest 10 sampled yearsCompared with BC lakes
Secchi depth6.2 m
2016–2025, 30 readings		Clearer than 68% of the 122 BC lakes with at least 5 readings.
Total phosphorus8.6 µg/L
2017–2026, 28 readings		Lower than 60% of the 269 BC lakes with at least 5 readings (lower is clearer).
Chlorophyll a2.6 µg/L
2017–2026, 28 readings		Higher than 61% of the 156 BC lakes with at least 5 readings.
Secchi depth how deep a black-and-white disc stays visible: deeper means clearer water
0510 19801990200020102020 1973: median 3.1 m from 1 reading1974: median 3.1 m from 1 reading1975: median 4.1 m from 4 readings1976: median 6.3 m from 2 readings1977: median 4.8 m from 4 readings1978: median 5.8 m from 4 readings1979: median 4.3 m from 4 readings1980: median 3.5 m from 4 readings1981: median 6.3 m from 2 readings1982: median 5.4 m from 2 readings1983: median 3.8 m from 1 reading1984: median 3.6 m from 1 reading1985: median 4.8 m from 45 readings1986: median 3.8 m from 3 readings1987: median 3.1 m from 3 readings1988: median 4.0 m from 3 readings1989: median 3.3 m from 3 readings1990: median 7.0 m from 3 readings1991: median 4.8 m from 3 readings1992: median 3.5 m from 3 readings1994: median 5.5 m from 22 readings1995: median 7.1 m from 3 readings1998: median 6.4 m from 3 readings1999: median 10 m from 3 readings2000: median 6.9 m from 3 readings2001: median 5.6 m from 19 readings2002: median 5.0 m from 15 readings2003: median 6.3 m from 10 readings2004: median 7.0 m from 8 readings2007: median 5.4 m from 4 readings2009: median 5.2 m from 14 readings2010: median 4.8 m from 15 readings2011: median 5.7 m from 13 readings2012: median 6.5 m from 15 readings2013: median 5.9 m from 15 readings2014: median 6.1 m from 13 readings2015: median 5.5 m from 13 readings2016: median 5.9 m from 3 readings2017: median 7.7 m from 3 readings2018: median 5.8 m from 3 readings2019: median 9.0 m from 3 readings2020: median 7.2 m from 3 readings2021: median 7.9 m from 3 readings2022: median 7.2 m from 3 readings2023: median 4.5 m from 3 readings2024: median 4.1 m from 3 readings2025: median 4.9 m from 3 readingsm
Total phosphorus the nutrient that most often feeds algae in BC lakes
10 19801990200020102020 1974: median 12 µg/L from 1 reading1975: median 13 µg/L from 4 readings1976: median 9.0 µg/L from 4 readings1977: median 13 µg/L from 4 readings1978: median 9.5 µg/L from 4 readings1979: median 14 µg/L from 4 readings1980: median 14 µg/L from 4 readings1981: median 14 µg/L from 2 readings1982: median 15 µg/L from 2 readings1983: median 14 µg/L from 1 reading1984: median 15 µg/L from 1 reading1985: median 14 µg/L from 38 readings1986: median 11 µg/L from 23 readings1987: median 16 µg/L from 3 readings1988: median 9.0 µg/L from 3 readings1989: median 13 µg/L from 3 readings1990: median 7.0 µg/L from 3 readings1991: median 11 µg/L from 3 readings1992: median 10 µg/L from 3 readings1993: median 6.0 µg/L from 3 readings1994: median 8.0 µg/L from 46 readings1995: median 9.5 µg/L from 6 readings1998: median 7.0 µg/L from 4 readings1999: median 5.0 µg/L from 3 readings2000: median 10 µg/L from 3 readings2001: median 9.0 µg/L from 18 readings2002: median 7.0 µg/L from 15 readings2003: median 10 µg/L from 11 readings2004: median 6.0 µg/L from 8 readings2005: median 5.0 µg/L from 19 readings2006: median 5.0 µg/L from 7 readings2007: median 7.0 µg/L from 7 readings2008: median 8.0 µg/L from 9 readings2009: median 6.0 µg/L from 15 readings2010: median 6.0 µg/L from 9 readings2011: median 5.0 µg/L from 9 readings2012: median 5.3 µg/L from 9 readings2013: median 5.7 µg/L from 8 readings2014: median 5.8 µg/L from 8 readings2015: median 3.9 µg/L from 11 readings2016: median 6.0 µg/L from 3 readings2017: median 9.2 µg/L from 3 readings2018: median 17 µg/L from 3 readings2019: median 5.8 µg/L from 3 readings2020: median 6.9 µg/L from 3 readings2021: median 7.4 µg/L from 3 readings2022: median 8.5 µg/L from 3 readings2023: median 8.7 µg/L from 3 readings2024: median 9.9 µg/L from 3 readings2025: median 8.4 µg/L from 3 readings2026: median 13 µg/L from 1 readingµg/L
Chlorophyll a the green pigment in algae: a direct measure of how much is growing
1310 19801990200020102020 1975: median 7.9 µg/L from 2 readings1976: median 2.5 µg/L from 2 readings1977: median 2.8 µg/L from 4 readings1978: median 3.2 µg/L from 4 readings1979: median 3.2 µg/L from 4 readings1980: median 4.8 µg/L from 4 readings1982: median 2.7 µg/L from 2 readings1983: median 4.6 µg/L from 1 reading1984: median 4.8 µg/L from 1 reading1986: median 1.9 µg/L from 9 readings1988: median 2.8 µg/L from 3 readings1989: median 9.3 µg/L from 3 readings1990: median 2.5 µg/L from 3 readings1991: median 4.7 µg/L from 3 readings1992: median 7.0 µg/L from 3 readings1993: median 4.2 µg/L from 3 readings1994: median 3.7 µg/L from 19 readings1995: median 1.9 µg/L from 3 readings1996: median 1.5 µg/L from 3 readings1998: median 4.3 µg/L from 3 readings1999: median 1.1 µg/L from 3 readings2000: median 3.2 µg/L from 3 readings2001: median 1.4 µg/L from 18 readings2002: median 3.2 µg/L from 13 readings2003: median 2.8 µg/L from 4 readings2004: median 2.8 µg/L from 8 readings2005: median 1.7 µg/L from 9 readings2006: median 2.9 µg/L from 12 readings2007: median 2.0 µg/L from 12 readings2008: median 2.0 µg/L from 15 readings2009: median 1.5 µg/L from 15 readings2010: median 1.4 µg/L from 15 readings2011: median 2.0 µg/L from 13 readings2012: median 1.0 µg/L from 15 readings2013: median 1.9 µg/L from 15 readings2014: median 1.3 µg/L from 13 readings2015: median 1.5 µg/L from 15 readings2016: median 2.9 µg/L from 3 readings2017: median 1.4 µg/L from 3 readings2018: median 2.6 µg/L from 3 readings2019: median 1.3 µg/L from 3 readings2020: median 2.1 µg/L from 3 readings2021: median 1.9 µg/L from 3 readings2022: median 2.7 µg/L from 3 readings2023: median 4.0 µg/L from 3 readings2024: median 4.7 µg/L from 3 readings2025: median 4.4 µg/L from 3 readings2026: median 9.3 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

The measures disagree: clarity reads oligotrophic, phosphorus reads oligotrophic, algae reads mesotrophic. That's common: clarity also depends on silt and colour, not just algae.

IndexClass
From secchi depth (6.2 m, 2016–2025)34oligotrophic
From total phosphorus (8.6 µg/L, 2017–2026)35oligotrophic
From chlorophyll a (2.6 µg/L, 2017–2026)40mesotrophic

Inferred by us, not a provincial classification. 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. 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.

Year by year

YearSecchi depthTotal phosphorusChlorophyll a
2026–13 µg/L (1)9.3 µg/L (1)
20254.9 m (3)8.4 µg/L (3)4.4 µg/L (3)
20244.1 m (3)9.9 µg/L (3)4.7 µg/L (3)
20234.5 m (3)8.7 µg/L (3)4.0 µg/L (3)
20227.2 m (3)8.5 µg/L (3)2.7 µg/L (3)
20217.9 m (3)7.4 µg/L (3)1.9 µg/L (3)
20207.2 m (3)6.9 µg/L (3)2.1 µg/L (3)
20199.0 m (3)5.8 µg/L (3)1.3 µg/L (3)
20185.8 m (3)17 µg/L (3)2.6 µg/L (3)
20177.7 m (3)9.2 µg/L (3)1.4 µg/L (3)
20165.9 m (3)6.0 µg/L (3)2.9 µg/L (3)
20155.5 m (13)3.9 µg/L (11)1.5 µg/L (15)
20146.1 m (13)5.8 µg/L (8)1.3 µg/L (13)
20135.9 m (15)5.7 µg/L (8)1.9 µg/L (15)
20126.5 m (15)5.3 µg/L (9)1.0 µg/L (15)
20115.7 m (13)5.0 µg/L (9)2.0 µg/L (13)
20104.8 m (15)6.0 µg/L (9)1.4 µg/L (15)
20095.2 m (14)6.0 µg/L (15)1.5 µg/L (15)
2008–8.0 µg/L (9)2.0 µg/L (15)
20075.4 m (4)7.0 µg/L (7)2.0 µg/L (12)
2006–5.0 µg/L (7)2.9 µg/L (12)
2005–5.0 µg/L (19)1.7 µg/L (9)
20047.0 m (8)6.0 µg/L (8)2.8 µg/L (8)
20036.3 m (10)10 µg/L (11)2.8 µg/L (4)
20025.0 m (15)7.0 µg/L (15)3.2 µg/L (13)
20015.6 m (19)9.0 µg/L (18)1.4 µg/L (18)
20006.9 m (3)10 µg/L (3)3.2 µg/L (3)
199910 m (3)5.0 µg/L (3)1.1 µg/L (3)
19986.4 m (3)7.0 µg/L (4)4.3 µg/L (3)
1996––1.5 µg/L (3)
19957.1 m (3)9.5 µg/L (6)1.9 µg/L (3)
19945.5 m (22)8.0 µg/L (46)3.7 µg/L (19)
1993–6.0 µg/L (3)4.2 µg/L (3)
19923.5 m (3)10 µg/L (3)7.0 µg/L (3)
19914.8 m (3)11 µg/L (3)4.7 µg/L (3)
19907.0 m (3)7.0 µg/L (3)2.5 µg/L (3)
19893.3 m (3)13 µg/L (3)9.3 µg/L (3)
19884.0 m (3)9.0 µg/L (3)2.8 µg/L (3)
19873.1 m (3)16 µg/L (3)–
19863.8 m (3)11 µg/L (23)1.9 µg/L (9)
19854.8 m (45)14 µg/L (38)–
19843.6 m (1)15 µg/L (1)4.8 µg/L (1)
19833.8 m (1)14 µg/L (1)4.6 µg/L (1)
19825.4 m (2)15 µg/L (2)2.7 µg/L (2)
19816.3 m (2)14 µg/L (2)–
19803.5 m (4)14 µg/L (4)4.8 µg/L (4)
19794.3 m (4)14 µg/L (4)3.2 µg/L (4)
19785.8 m (4)9.5 µg/L (4)3.2 µg/L (4)
19774.8 m (4)13 µg/L (4)2.8 µg/L (4)
19766.3 m (2)9.0 µg/L (4)2.5 µg/L (2)
19754.1 m (4)13 µg/L (4)7.9 µg/L (2)
19743.1 m (1)12 µg/L (1)–
19733.1 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

  • 0500615 SKAHA L OPP. GILLIES 597 readings
  • 0500846 SKAHA L SOUTH BASIN 474 readings
  • 0500453 SKAHA L WEST OKANAGAN R MOUTH 324 readings
  • 0500250 SKAHA L OPP GREYLEDGE 66 readings
  • E276556 SKAHA LAKE (SKA-1) NORTH OF KALEDEN PUBLIC BEACH 1 reading
  • E221959 EAST SIDE OF SKAHA LAKE SOUTH OF PENTICTON 1 reading
  • E276557 SKAHA LK (SKA-3) 650M NORTH OF BANBURY POINT BESIDE KVR 1 reading
  • E276558 SKAHA LK (SKA-4) NW CORNER OPPOSITE 0500453 1 reading
  • E221957 SKAHA LAKE AT KALEDON PIONEER PARK 1 reading
  • E276564 SKAHA LAKE (SKA-2) SKAHA ESTATES BOAT LAUNCH BEACH 1 reading
  • E221958 EAST SIDE OF SKAHA LAKE; AT DOG SWIMMING AREA 1 reading

Site names and IDs are as recorded in the provincial database; 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. Each year's figure is the median of that year's readings; the summary is the median of every reading in the lake's latest 10 sampled years. 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.