Country: Canada
United StatesCanadaUnited Kingdom

Altawan Reservoir water level history

Daily records since 1960 · Level today: 897.800 m

Highest on record
901.322 m
Sep 26, 1986
Lowest on record
889.284 m
Feb 29, 1960
Today
897.800 m
Oct 23, 2026
Years of data
67
since 1960

In short

Across 5 complete years, 2022 had the lowest average level (897.243 m) and 2021 the highest (898.901 m).

On average the lake is lowest in October (896.123 m) and highest in April (898.273 m).

Altawan Reservoir level, all years

Loading chart…

Measured Normal range for the date (middle 50% of past years)

Each year's lowest and highest level

8898928958999021960196819761984199220002008201620261960: lowest 889.28 m (1960-02-29), highest 895.85 m (1960-04-05), average 892.13 m, 16 days measured1961: lowest 890.74 m (1961-10-31), highest 893.86 m (1961-03-31), average 892.04 m, 23 days measured1962: lowest 890.44 m (1962-02-28), highest 898.01 m (1962-06-26), average 896.04 m, 24 days measured1963: lowest 896.51 m (1963-02-28), highest 900.12 m (1963-07-13), average 897.69 m, 49 days measured1964: lowest 893.61 m (1964-10-28), highest 898.71 m (1964-05-11), average 896.64 m, 71 days measured1965: lowest 893.68 m (1965-02-26), highest 901.23 m (1965-06-26), average 898.64 m, 56 days measured1966: lowest 897.47 m (1966-10-31), highest 900.02 m (1966-03-31), average 898.79 m, 55 days measured1967: lowest 897.46 m (1967-02-28), highest 900.29 m (1967-05-08), average 898.27 m, 136 days measured1968: lowest 894.00 m (1968-10-28), highest 898.82 m (1968-04-10), average 896.26 m, 244 days measured1969: lowest 893.99 m (1969-02-28), highest 900.23 m (1969-04-11), average 897.76 m, 211 days measured1970: lowest 894.74 m (1970-11-02), highest 900.03 m (1970-04-15), average 896.38 m, 234 days measured1971: lowest 894.74 m (1971-03-21), highest 900.25 m (1971-04-23), average 896.97 m, 234 days measured1972: lowest 895.68 m (1972-10-31), highest 900.43 m (1972-03-18), average 897.27 m, 227 days measured1973: lowest 890.63 m (1973-10-31), highest 896.98 m (1973-05-06), average 894.24 m, 247 days measured1974: lowest 891.48 m (1974-02-26), highest 899.99 m (1974-06-01), average 897.90 m, 217 days measured1975: lowest 896.98 m (1975-03-06), highest 900.54 m (1975-05-07), average 898.83 m, 248 days measured1976: lowest 897.44 m (1976-11-02), highest 900.52 m (1976-03-18), average 898.82 m, 260 days measured1977: lowest 890.78 m (1977-08-02), highest 897.46 m (1977-04-13), average 894.44 m, 246 days measured1978: lowest 891.21 m (1978-03-01), highest 900.41 m (1978-04-19), average 897.90 m, 245 days measured1979: lowest 896.87 m (1979-10-30), highest 900.39 m (1979-04-19), average 898.56 m, 245 days measured1980: lowest 889.60 m (1980-09-27), highest 897.21 m (1980-04-21), average 893.89 m, 248 days measured1981: lowest 889.32 m (1981-10-29), highest 895.95 m (1981-05-20), average 892.93 m, 249 days measured1982: lowest 889.60 m (1982-03-01), highest 900.01 m (1982-05-21), average 897.16 m, 245 days measured1983: lowest 894.56 m (1983-10-16), highest 898.64 m (1983-05-30), average 896.80 m, 253 days measured1984: lowest 889.33 m (1984-10-30), highest 895.05 m (1984-04-10), average 891.72 m, 259 days measured1985: lowest 889.83 m (1985-07-19), highest 898.50 m (1985-04-17), average 893.97 m, 198 days measured1986: lowest 891.16 m (1986-02-03), highest 901.32 m (1986-09-26), average 898.66 m, 274 days measured1987: lowest 897.49 m (1987-10-25), highest 900.11 m (1987-04-06), average 898.74 m, 265 days measured1988: lowest 893.28 m (1988-10-29), highest 898.19 m (1988-04-10), average 895.40 m, 249 days measured1989: lowest 889.92 m (1989-05-20), highest 896.20 m (1989-05-04), average 892.83 m, 255 days measured1990: lowest 891.95 m (1990-02-23), highest 900.29 m (1990-05-27), average 898.65 m, 251 days measured1991: lowest 896.48 m (1991-10-18), highest 900.22 m (1991-05-15), average 898.06 m, 249 days measured1992: lowest 893.63 m (1992-06-29), highest 896.45 m (1992-03-20), average 894.79 m, 278 days measured1993: lowest 893.87 m (1993-02-19), highest 900.74 m (1993-03-26), average 898.68 m, 276 days measured1994: lowest 898.00 m (1994-10-30), highest 900.40 m (1994-03-19), average 899.13 m, 253 days measured1995: lowest 896.40 m (1995-10-31), highest 898.36 m (1995-04-19), average 897.43 m, 273 days measured1996: lowest 896.42 m (1996-02-28), highest 901.24 m (1996-04-08), average 899.06 m, 252 days measured1997: lowest 898.15 m (1997-02-23), highest 900.71 m (1997-03-26), average 899.09 m, 279 days measured1998: lowest 895.88 m (1998-11-05), highest 898.63 m (1998-07-16), average 897.28 m, 255 days measured1999: lowest 893.92 m (1999-11-02), highest 899.15 m (1999-05-25), average 896.34 m, 253 days measured2000: lowest 892.85 m (2000-11-02), highest 893.91 m (2000-04-17), average 893.46 m, 250 days measured2001: lowest 890.04 m (2001-11-15), highest 892.76 m (2001-04-14), average 891.40 m, 269 days measured2002: lowest 890.04 m (2002-02-27), highest 899.94 m (2002-06-19), average 894.48 m, 252 days measured2003: lowest 895.06 m (2003-03-06), highest 900.27 m (2003-03-23), average 898.16 m, 259 days measured2004: lowest 897.12 m (2004-11-03), highest 899.99 m (2004-04-08), average 898.20 m, 254 days measured2005: lowest 898.05 m (2005-06-08), highest 899.65 m (2005-04-26), average 898.71 m, 249 days measured2006: lowest 896.37 m (2006-11-01), highest 900.23 m (2006-04-03), average 897.75 m, 253 days measured2007: lowest 894.52 m (2007-11-07), highest 899.67 m (2007-05-15), average 896.23 m, 254 days measured2008: lowest 891.97 m (2008-06-09), highest 895.82 m (2008-05-13), average 894.19 m, 253 days measured2009: lowest 891.73 m (2009-10-31), highest 897.98 m (2009-04-28), average 893.56 m, 248 days measured2010: lowest 891.55 m (2010-03-15), highest 900.82 m (2010-06-20), average 898.18 m, 267 days measured2011: lowest 899.11 m (2011-10-30), highest 900.88 m (2011-06-05), average 899.78 m, 245 days measured2012: lowest 897.49 m (2012-10-22), highest 899.68 m (2012-05-05), average 898.47 m, 245 days measured2013: lowest 897.48 m (2013-03-05), highest 900.09 m (2013-04-05), average 899.22 m, 243 days measured2014: lowest 898.65 m (2014-08-21), highest 900.29 m (2014-03-18), average 899.19 m, 245 days measured2015: lowest 897.54 m (2015-10-31), highest 900.34 m (2015-03-14), average 898.68 m, 245 days measured2016: lowest 896.94 m (2016-07-24), highest 898.83 m (2016-05-10), average 897.72 m, 245 days measured2017: lowest 897.39 m (2017-11-02), highest 901.08 m (2017-03-19), average 898.73 m, 261 days measured2018: lowest 897.39 m (2018-03-12), highest 900.92 m (2018-04-21), average 898.53 m, 252 days measured2019: lowest 896.10 m (2019-11-01), highest 899.32 m (2019-04-17), average 897.38 m, 253 days measured2020: lowest 896.11 m (2020-03-10), highest 900.42 m (2020-04-11), average 899.03 m, 310 days measured2021: lowest 898.08 m (2021-12-31), highest 900.20 m (2021-03-17), average 898.90 m, 365 days measured2022: lowest 896.11 m (2022-12-11), highest 899.03 m (2022-04-20), average 897.24 m, 365 days measured2023: lowest 896.11 m (2023-02-17), highest 900.87 m (2023-04-18), average 897.97 m, 365 days measured2024: lowest 898.12 m (2024-01-06), highest 900.41 m (2024-03-16), average 898.89 m, 366 days measured2025: lowest 898.26 m (2025-11-13), highest 900.11 m (2025-04-14), average 898.75 m, 365 days measured2026: lowest 897.80 m (2026-10-21), highest 897.88 m (2026-09-22), average 897.83 m, 30 days measured
889892895899902196019771994201120261960: lowest 889.28 m (1960-02-29), highest 895.85 m (1960-04-05), average 892.13 m, 16 days measured1961: lowest 890.74 m (1961-10-31), highest 893.86 m (1961-03-31), average 892.04 m, 23 days measured1962: lowest 890.44 m (1962-02-28), highest 898.01 m (1962-06-26), average 896.04 m, 24 days measured1963: lowest 896.51 m (1963-02-28), highest 900.12 m (1963-07-13), average 897.69 m, 49 days measured1964: lowest 893.61 m (1964-10-28), highest 898.71 m (1964-05-11), average 896.64 m, 71 days measured1965: lowest 893.68 m (1965-02-26), highest 901.23 m (1965-06-26), average 898.64 m, 56 days measured1966: lowest 897.47 m (1966-10-31), highest 900.02 m (1966-03-31), average 898.79 m, 55 days measured1967: lowest 897.46 m (1967-02-28), highest 900.29 m (1967-05-08), average 898.27 m, 136 days measured1968: lowest 894.00 m (1968-10-28), highest 898.82 m (1968-04-10), average 896.26 m, 244 days measured1969: lowest 893.99 m (1969-02-28), highest 900.23 m (1969-04-11), average 897.76 m, 211 days measured1970: lowest 894.74 m (1970-11-02), highest 900.03 m (1970-04-15), average 896.38 m, 234 days measured1971: lowest 894.74 m (1971-03-21), highest 900.25 m (1971-04-23), average 896.97 m, 234 days measured1972: lowest 895.68 m (1972-10-31), highest 900.43 m (1972-03-18), average 897.27 m, 227 days measured1973: lowest 890.63 m (1973-10-31), highest 896.98 m (1973-05-06), average 894.24 m, 247 days measured1974: lowest 891.48 m (1974-02-26), highest 899.99 m (1974-06-01), average 897.90 m, 217 days measured1975: lowest 896.98 m (1975-03-06), highest 900.54 m (1975-05-07), average 898.83 m, 248 days measured1976: lowest 897.44 m (1976-11-02), highest 900.52 m (1976-03-18), average 898.82 m, 260 days measured1977: lowest 890.78 m (1977-08-02), highest 897.46 m (1977-04-13), average 894.44 m, 246 days measured1978: lowest 891.21 m (1978-03-01), highest 900.41 m (1978-04-19), average 897.90 m, 245 days measured1979: lowest 896.87 m (1979-10-30), highest 900.39 m (1979-04-19), average 898.56 m, 245 days measured1980: lowest 889.60 m (1980-09-27), highest 897.21 m (1980-04-21), average 893.89 m, 248 days measured1981: lowest 889.32 m (1981-10-29), highest 895.95 m (1981-05-20), average 892.93 m, 249 days measured1982: lowest 889.60 m (1982-03-01), highest 900.01 m (1982-05-21), average 897.16 m, 245 days measured1983: lowest 894.56 m (1983-10-16), highest 898.64 m (1983-05-30), average 896.80 m, 253 days measured1984: lowest 889.33 m (1984-10-30), highest 895.05 m (1984-04-10), average 891.72 m, 259 days measured1985: lowest 889.83 m (1985-07-19), highest 898.50 m (1985-04-17), average 893.97 m, 198 days measured1986: lowest 891.16 m (1986-02-03), highest 901.32 m (1986-09-26), average 898.66 m, 274 days measured1987: lowest 897.49 m (1987-10-25), highest 900.11 m (1987-04-06), average 898.74 m, 265 days measured1988: lowest 893.28 m (1988-10-29), highest 898.19 m (1988-04-10), average 895.40 m, 249 days measured1989: lowest 889.92 m (1989-05-20), highest 896.20 m (1989-05-04), average 892.83 m, 255 days measured1990: lowest 891.95 m (1990-02-23), highest 900.29 m (1990-05-27), average 898.65 m, 251 days measured1991: lowest 896.48 m (1991-10-18), highest 900.22 m (1991-05-15), average 898.06 m, 249 days measured1992: lowest 893.63 m (1992-06-29), highest 896.45 m (1992-03-20), average 894.79 m, 278 days measured1993: lowest 893.87 m (1993-02-19), highest 900.74 m (1993-03-26), average 898.68 m, 276 days measured1994: lowest 898.00 m (1994-10-30), highest 900.40 m (1994-03-19), average 899.13 m, 253 days measured1995: lowest 896.40 m (1995-10-31), highest 898.36 m (1995-04-19), average 897.43 m, 273 days measured1996: lowest 896.42 m (1996-02-28), highest 901.24 m (1996-04-08), average 899.06 m, 252 days measured1997: lowest 898.15 m (1997-02-23), highest 900.71 m (1997-03-26), average 899.09 m, 279 days measured1998: lowest 895.88 m (1998-11-05), highest 898.63 m (1998-07-16), average 897.28 m, 255 days measured1999: lowest 893.92 m (1999-11-02), highest 899.15 m (1999-05-25), average 896.34 m, 253 days measured2000: lowest 892.85 m (2000-11-02), highest 893.91 m (2000-04-17), average 893.46 m, 250 days measured2001: lowest 890.04 m (2001-11-15), highest 892.76 m (2001-04-14), average 891.40 m, 269 days measured2002: lowest 890.04 m (2002-02-27), highest 899.94 m (2002-06-19), average 894.48 m, 252 days measured2003: lowest 895.06 m (2003-03-06), highest 900.27 m (2003-03-23), average 898.16 m, 259 days measured2004: lowest 897.12 m (2004-11-03), highest 899.99 m (2004-04-08), average 898.20 m, 254 days measured2005: lowest 898.05 m (2005-06-08), highest 899.65 m (2005-04-26), average 898.71 m, 249 days measured2006: lowest 896.37 m (2006-11-01), highest 900.23 m (2006-04-03), average 897.75 m, 253 days measured2007: lowest 894.52 m (2007-11-07), highest 899.67 m (2007-05-15), average 896.23 m, 254 days measured2008: lowest 891.97 m (2008-06-09), highest 895.82 m (2008-05-13), average 894.19 m, 253 days measured2009: lowest 891.73 m (2009-10-31), highest 897.98 m (2009-04-28), average 893.56 m, 248 days measured2010: lowest 891.55 m (2010-03-15), highest 900.82 m (2010-06-20), average 898.18 m, 267 days measured2011: lowest 899.11 m (2011-10-30), highest 900.88 m (2011-06-05), average 899.78 m, 245 days measured2012: lowest 897.49 m (2012-10-22), highest 899.68 m (2012-05-05), average 898.47 m, 245 days measured2013: lowest 897.48 m (2013-03-05), highest 900.09 m (2013-04-05), average 899.22 m, 243 days measured2014: lowest 898.65 m (2014-08-21), highest 900.29 m (2014-03-18), average 899.19 m, 245 days measured2015: lowest 897.54 m (2015-10-31), highest 900.34 m (2015-03-14), average 898.68 m, 245 days measured2016: lowest 896.94 m (2016-07-24), highest 898.83 m (2016-05-10), average 897.72 m, 245 days measured2017: lowest 897.39 m (2017-11-02), highest 901.08 m (2017-03-19), average 898.73 m, 261 days measured2018: lowest 897.39 m (2018-03-12), highest 900.92 m (2018-04-21), average 898.53 m, 252 days measured2019: lowest 896.10 m (2019-11-01), highest 899.32 m (2019-04-17), average 897.38 m, 253 days measured2020: lowest 896.11 m (2020-03-10), highest 900.42 m (2020-04-11), average 899.03 m, 310 days measured2021: lowest 898.08 m (2021-12-31), highest 900.20 m (2021-03-17), average 898.90 m, 365 days measured2022: lowest 896.11 m (2022-12-11), highest 899.03 m (2022-04-20), average 897.24 m, 365 days measured2023: lowest 896.11 m (2023-02-17), highest 900.87 m (2023-04-18), average 897.97 m, 365 days measured2024: lowest 898.12 m (2024-01-06), highest 900.41 m (2024-03-16), average 898.89 m, 366 days measured2025: lowest 898.26 m (2025-11-13), highest 900.11 m (2025-04-14), average 898.75 m, 365 days measured2026: lowest 897.80 m (2026-10-21), highest 897.88 m (2026-09-22), average 897.83 m, 30 days measured
Lowest to highest that yearYear average2026 so far

One bar per year from the lowest to the highest daily level, with the year's average. Years with no bar have no daily record in the agency archive.

Lowest years

Years ranked by their lowest daily level.

  • 2023896.110 m on Feb 17
  • 2022896.112 m on Dec 11
  • 2021898.083 m on Dec 31
  • 2024898.120 m on Jan 6
  • 2025898.264 m on Nov 13

Yearly highs and lows

YearAverageLowLow dateHighHigh date
2026 (30 days)897.834897.800Oct 21897.882Sep 22
2025898.752898.264Nov 13900.105Apr 14
2024898.888898.120Jan 6900.410Mar 16
2023897.967896.110Feb 17900.872Apr 18
2022897.243896.112Dec 11899.029Apr 20
2021898.901898.083Dec 31900.199Mar 17
2020 (310 days)899.030896.114Mar 10900.420Apr 11
2019 (253 days)897.381896.101Nov 1899.320Apr 17
2018 (252 days)898.535897.393Mar 12900.920Apr 21
2017 (261 days)898.734897.387Nov 2901.083Mar 19
2016 (245 days)897.723896.942Jul 24898.825May 10
2015 (245 days)898.682897.541Oct 31900.344Mar 14
2014 (245 days)899.191898.647Aug 21900.292Mar 18
2013 (243 days)899.220897.477Mar 5900.088Apr 5
2012 (245 days)898.466897.487Oct 22899.678May 5
2011 (245 days)899.785899.106Oct 30900.880Jun 5
2010 (267 days)898.178891.548Mar 15900.823Jun 20
2009 (248 days)893.556891.734Oct 31897.983Apr 28
2008 (253 days)894.185891.967Jun 9895.820May 13
2007 (254 days)896.233894.521Nov 7899.666May 15
2006 (253 days)897.745896.365Nov 1900.229Apr 3
2005 (249 days)898.709898.054Jun 8899.649Apr 26
2004 (254 days)898.200897.120Nov 3899.991Apr 8
2003 (259 days)898.158895.058Mar 6900.265Mar 23
2002 (252 days)894.477890.037Feb 27899.941Jun 19
2001 (269 days)891.399890.037Nov 15892.763Apr 14
2000 (250 days)893.460892.850Nov 2893.912Apr 17
1999 (253 days)896.339893.924Nov 2899.152May 25
1998 (255 days)897.285895.880Nov 5898.633Jul 16
1997 (279 days)899.085898.153Feb 23900.712Mar 26
1996 (252 days)899.056896.424Feb 28901.242Apr 8
1995 (273 days)897.430896.402Oct 31898.361Apr 19
1994 (253 days)899.126897.995Oct 30900.402Mar 19
1993 (276 days)898.682893.871Feb 19900.735Mar 26
1992 (278 days)894.794893.632Jun 29896.452Mar 20
1991 (249 days)898.060896.478Oct 18900.216May 15
1990 (251 days)898.650891.948Feb 23900.292May 27
1989 (255 days)892.827889.920May 20896.202May 4
1988 (249 days)895.404893.284Oct 29898.188Apr 10
1987 (265 days)898.738897.494Oct 25900.110Apr 6
1986 (274 days)898.660891.161Feb 3901.322Sep 26
1985 (198 days)893.969889.829Jul 19898.501Apr 17
1984 (259 days)891.721889.325Oct 30895.049Apr 10
1983 (253 days)896.796894.558Oct 16898.640May 30
1982 (245 days)897.158889.600Mar 1900.014May 21
1981 (249 days)892.928889.322Oct 29895.945May 20
1980 (248 days)893.887889.598Sep 27897.210Apr 21
1979 (245 days)898.560896.867Oct 30900.391Apr 19
1978 (245 days)897.898891.205Mar 1900.407Apr 19
1977 (246 days)894.436890.778Aug 2897.462Apr 13
1976 (260 days)898.819897.441Nov 2900.522Mar 18
1975 (248 days)898.829896.981Mar 6900.541May 7
1974 (217 days)897.899891.479Feb 26899.989Jun 1
1973 (247 days)894.239890.626Oct 31896.981May 6
1972 (227 days)897.274895.682Oct 31900.434Mar 18
1971 (234 days)896.974894.743Mar 21900.248Apr 23
1970 (234 days)896.379894.737Nov 2900.032Apr 15
1969 (211 days)897.755893.988Feb 28900.230Apr 11
1968 (244 days)896.262894.000Oct 28898.816Apr 10
1967 (136 days)898.265897.462Feb 28900.288May 8
1966 (55 days)898.794897.471Oct 31900.020Mar 31
1965 (56 days)898.639893.677Feb 26901.230Jun 26
1964 (71 days)896.636893.613Oct 28898.712May 11
1963 (49 days)897.690896.508Feb 28900.123Jul 13
1962 (24 days)896.042890.443Feb 28898.011Jun 26
1961 (23 days)892.038890.741Oct 31893.856Mar 31
1960 (16 days)892.132889.284Feb 29895.850Apr 5

Levels in metres. Partial years show the number of days with data.

Monthly averages

MonthAverageLowestHighest
January897.941896.116898.947
February896.602889.284900.175
March896.945889.600901.083
April898.273889.600901.242
May898.245889.920900.541
June897.529890.481901.230
July897.275889.829900.123
August896.401889.855900.026
September896.165889.598901.322
October896.123889.322899.864
November897.185890.037899.864
December898.008896.112898.969

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Daily levels as CSV (15,610 rows; credit the original agencies listed below)