PlaceDossier / BC places / Lakes

BC lake · 20 km² · Nechako River watershed

Cluculz Lake

Its median summer Secchi depth over 2017–2025 was 4.0 m, from 30 readings. Murkier than 64% of the 122 BC lakes with at least 5 readings.

The readings

223 summer readings on record from 1985 to 2026, at 4 sampling sites.

Median, latest 10 sampled yearsCompared with BC lakes
Secchi depth4.0 m
2017–2025, 30 readings		Murkier than 64% of the 122 BC lakes with at least 5 readings.
Total phosphorus16 µg/L
2017–2026, 54 readings		Higher than 66% of the 269 BC lakes with at least 5 readings.
Chlorophyll a5.1 µg/L
2017–2026, 53 readings		Higher than 80% 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
0246 1990200020102020 2017: median 3.8 m from 2 readings2018: median 2.8 m from 2 readings2019: median 1.7 m from 2 readings2020: median 3.8 m from 1 reading2021: median 2.8 m from 2 readings2022: median 4.0 m from 5 readings2023: median 4.3 m from 12 readings2024: median 4.9 m from 2 readings2025: median 4.7 m from 2 readingsm
Total phosphorus the nutrient that most often feeds algae in BC lakes
1030 1990200020102020 1985: median 20 µg/L from 2 readings1993: median 20 µg/L from 1 reading1994: median 14 µg/L from 6 readings1995: median 15 µg/L from 17 readings1996: median 15 µg/L from 10 readings1997: median 35 µg/L from 5 readings1998: median 18 µg/L from 5 readings1999: median 17 µg/L from 8 readings2000: median 24 µg/L from 4 readings2002: median 21 µg/L from 10 readings2011: median 29 µg/L from 2 readings2017: median 17 µg/L from 2 readings2018: median 26 µg/L from 2 readings2019: median 18 µg/L from 2 readings2020: median 14 µg/L from 1 reading2021: median 18 µg/L from 13 readings2022: median 22 µg/L from 14 readings2023: median 11 µg/L from 14 readings2024: median 19 µg/L from 2 readings2025: median 15 µg/L from 2 readings2026: median 12 µg/L from 2 readingsµg/L
Chlorophyll a the green pigment in algae: a direct measure of how much is growing
1310 1990200020102020 1985: median 3.9 µg/L from 1 reading1993: median 3.4 µg/L from 2 readings2002: median 7.3 µg/L from 12 readings2011: median 21 µg/L from 1 reading2017: median 3.2 µg/L from 2 readings2018: median 9.6 µg/L from 2 readings2019: median 6.5 µg/L from 2 readings2020: median 3.1 µg/L from 1 reading2021: median 11 µg/L from 13 readings2022: median 5.5 µg/L from 14 readings2023: median 3.5 µg/L from 14 readings2024: median 3.0 µg/L from 2 readings2025: median 5.9 µg/L from 2 readings2026: median 1.5 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 mesotrophic (moderate nutrients and algae).

IndexClass
From secchi depth (4.0 m, 2017–2025)40mesotrophic
From total phosphorus (16 µg/L, 2017–2026)44mesotrophic
From chlorophyll a (5.1 µg/L, 2017–2026)47mesotrophic

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
2026–12 µg/L (2)1.5 µg/L (1)
20254.7 m (2)15 µg/L (2)5.9 µg/L (2)
20244.9 m (2)19 µg/L (2)3.0 µg/L (2)
20234.3 m (12)11 µg/L (14)3.5 µg/L (14)
20224.0 m (5)22 µg/L (14)5.5 µg/L (14)
20212.8 m (2)18 µg/L (13)11 µg/L (13)
20203.8 m (1)14 µg/L (1)3.1 µg/L (1)
20191.7 m (2)18 µg/L (2)6.5 µg/L (2)
20182.8 m (2)26 µg/L (2)9.6 µg/L (2)
20173.8 m (2)17 µg/L (2)3.2 µg/L (2)
2011–29 µg/L (2)21 µg/L (1)
2002–21 µg/L (10)7.3 µg/L (12)
2000–24 µg/L (4)–
1999–17 µg/L (8)–
1998–18 µg/L (5)–
1997–35 µg/L (5)–
1996–15 µg/L (10)–
1995–15 µg/L (17)–
1994–14 µg/L (6)–
1993–20 µg/L (1)3.4 µg/L (2)
1985–20 µg/L (2)3.9 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

  • 0400502 CLUCULZ L DEEP STN EAST ARM CENTER 120 readings
  • E221884 CLUCULZ LAKE WEST OF MAIN ISLAND 111 readings
  • E219014 CLUCULZ LAKE DEEP STATION WEST ARM 1 reading
  • E227140 CLUCULZ LAKE LITTORAL SITE 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.