Historical Water Levels of Clear Lake

The level of Clear Lake is measured in reference to the "RUMSEY GAGE".

Zero Rumsey is equal to 1318.257 feet above mean sea level. A full lake, by definition, is reached when the lake measures 7.56 feet on the Rumsey Gage.

The level of Clear Lake is controlled by Cache Creek Dam which was constructed on Cache Creek in 1914. This dam is owned and operated by Yolo County Flood Control and Water Conservation District and is operated in conformance with two court decrees. The Gopcevic Decree of 1920 stipulated that the lake shall be operated between Zero and 7.56 feet, except for unforeseen storms that raise the level faster than the Cache Creek channel capacity can draw down. In that event the level may go up to 9.0 feet, but not for a period of more than l0 consecutive days. It must be noted that with a full lake, the outlet capacity of Cache Creek is limited to 2,540 cubic feet per second. During the January 1995 storm, peak inflows of 37,400 cfs occurred.  Due to the limited outlet capacity of Cache Creek, it is virtually impossible with this latter requirement.

Statistically the following peak flood levels can be expected on Clear Lake:

10% chance each year 10.04 feet
2% chance each year 11.74 feet
1% chance each year 12.34 feet
0.2% chance each year 13.84 feet

The Solano Decree of 1978 very specifically outlines the operation of Clear Lake for Yolo irrigation purposes. If the lake is full on May 1, Yolo may withdraw 150,000 acre-feet of water and the level on October 31 may not be below 1.25 feet Rumsey. If the lake is 3.22 feet or lower on May 1, no water may be released. Evaporation on Clear Lake through the average summer is 3 feet.

As a point of interest, when Clear Lake is full it has a surface area of 43,790 acres and contains 1,155,000 acre-feet of water.

At Zero the surface area is 39,170 acres with a capacity of 842,000 acre-feet.

For more detailed information please contact the Lake County Department of Public Works, Water Resources Division.

Year

MONTH

High Lake Level

MONTH

Low Lake Level

Annual Rainfall

2008

Mar.

7.11

 

 

 

2007

Mar.

6.14

 Dec.

0.97

 

2006

Apr.

8.77

Oct.

2.79

 

2005

May

7.85

Nov.

3.20

 

2004

Feb.

8.85

Oct.

1.29

 

2003

May

7.86

Nov.

2.14

 

2002

Apr.

6.89

Nov. 

1.07

 

2001

Mar.

5.20

Oct.

0.85

19.8

2000

Apr.

7.69

Nov.

1.12

30.75

1999

Mar.

7.79

Dec.

1.36

26.53

1998

Feb.

11.44

Nov.

2.74

57.13

1997

Jan.

8.5

Nov.

1.34

18.37

1996

Mar.

8.05

Nov.

2.00

40.56

1995

Mar.

10.72

Nov.

2.70

57.64

1994

Mar.

4.39

Oct.

0.44

20.68

1993

Feb.

8.48

Nov.

1.76

40.09

1992

Apr.

4.54

Nov.

0.52

22.74

1991

Apr.

3.98

Dec.

0.43

22.43

1990

Mar.

3.39

Dec.

0.32

18.55

1989

May

5.27

Dec.

1.47

23.93

1988

Feb.

5.94

Nov.

1.02

23.45

1987

Apr.

4.86

Nov.

0.81

18.01

1986

Feb.

11.34

Nov.

1.54

43.03

1985

Apr.

6.25

Nov.

1.37

25.85

1984

Mar.

7.93

Oct.

1.83

32.06

1983

Mar.

11.32

Oct.

3.57

62.04

1982

Apr.

9.17

Oct.

2.37

44.99

1981

Apr.

6.79

Oct.

1.04

20.57

1980

Feb.

9.61

Nov.

2.49

40.81

1979

May

6.62

Oct.

1.38

24.71

1978

Mar.

8.1

Dec.

1.43

45.06

1977

Feb.

-0.30

Nov.

-3.39

12.46

1976

Apr.

2.32

Nov.

-0.60

12.19

1975

Mar.

8.90

Oct.

1.68

31.62

1974

Apr.

9.10

Nov.

1.70

46.95

1973

Feb.

7.74

Nov.

1.28

38.01

1972

Apr.

4.58

Oct.

0.54

19.6

1971

Mar.

7.84

Oct.

1.60

33.14

1970

Jan.

10.37

Oct.

1.37

38.94

1969

Feb.

8.80

Dec.

1.74

40.41

1968

Mar.

7.71

Oct.

1.41

35.66

1967

Mar.

7.92

Nov.

3.02

32.07

1966

Mar.

7.59

Oct.

1.05

25.59

1965

Jan.

9.03

Nov.

2.50

28.5

1964

Mar.

5.88

Oct.

0.31

32.31

1963

Apr.

8.20

Oct.

3.17

30.87

1962

Mar.

7.75

Oct.

1.88

28.2

1961

Apr.

7.18

Nov.

1.76

20.3

1960

Apr.

6.71

Jan.

1.29

31.59

1959

Apr.

7.48

Dec.

1.18

21.57

1958

Feb.

10.86

Dec.

3.32

37.98

1957

Apr.

7.06

Sept.

2.69

35.18

1956

Feb.

9.53

Dec.

2.35

23.1

1955

Mar.

4.71

Nov.

-0.12

28.68

1954

Apr.

7.67

Nov.

1.58

30.37

1953

Jan.

7.81

Nov.

2.41

22.39

1952

Feb.

8.08

Nov.

1.45

35

1951

Mar.-Apr.

7.38

Nov.

1.56

33.31

1950

Apr.

4.65

Oct.

-0.135

36.75

1949

Apr.

5.95

Nov.

0.13

16.09

1948

May

4.62

Dec.

0.55

27

1947

Apr.

3.41

Dec.

0.00

19.11

1946

Apr.

7.23

Nov.

0.08

16.03

1945

Apr.

5.82

Sept.

0.1

34.91

1944

Apr.

5.03

Oct.

0.45

28.91

1943

Apr.

7.72

Dec.

1.30

21.24

1942

Feb.

9.60

Nov.

2.32

36.62

1941

Apr.

8.90

Nov.

3.05

45.71

1940

Mar.

8.33

Oct.

2.55

46.64

1939

Apr.

3.75

Dec.

-0.36

15.01

1938

Feb.

10.25

Dec.

2.10

33.54

1937

Apr.

7.05

Nov.

1.10

40.42

1936

Feb.

8.20

Dec.

1.85

26.91

1935

Apr.

7.28

Nov.-Dec.

0.78

26.82

1934

Mar.-Apr.

3.60

Oct.

0.07

21.02

1933

Apr.

2.60

N.A.

  N.A.

22.35

1932

Mar.-Apr.

3.78

Nov.-Dec.

-0.10

13.55

1931

Mar.-Apr.

2.20

Dec.

-0.85

14.29

1930

Apr.

6.00

Dec.

1.25

 

1929

Mar.-Apr.

3.30

Dec.

-0.32

 

1928

Apr.

7.35

Oct.-Nov.

1.70

 

1927

Feb.

9.00

Oct.-Nov.

1.30

 

1926

Apr.

7.47

Nov.

1.90

 

1925

May

6.90

Nov.

2.00

 

1924

Feb.

1.80

Oct.

-1.53

 

1923

Apr.

5.70

Dec.

0.70

 

1922

Apr.

6.50

Oct.

1.18

 

1921

Mar.-Apr.

7.20

Nov.

1.75

 

1920

Apr.-May

-0.50

Sept.

-3.50

 

1919

Apr.

4.42

Nov.-Dec.

-1.50

 

1918

Apr.

3.03

Oct.

-2.00

 

1917

Apr.

6.60

Dec.

0.61

 

1916

Feb.

8.53

Nov.

1.37

 

1915

Feb.

10.68

Nov.

2.48

 

1914

Jan.

11.12

Nov.-Dec.

2.78

 

1913

Jan.-Feb.

4.16

Oct.

0.62

 

1912

Mar.

3.78

    N.A.

        N.A. 

 

1911

Mar.

9.09

Jan.

1.27

 

1910

Apr.

6.95

Nov.-Dec.

1.27

 

1909

Feb.

13.38

Nov.

2.42

 

1908

Mar.

7.53

Oct.-Nov.

1.37

 

1907

Mar.

11.64

Nov.

2.42

 

1906

Apr.

9.66

Dec.

2.17

 

1905

Apr.

8.68

Nov.

1.72

 

1904

Apr.

11.91

Nov.

2.67

 

1903

Mar.

7.81

Oct.-Nov.

1.67

 

1902

Mar.

9.98

Oct.-Nov.

2.77

 

1901

Feb.-Mar.

8.13

Nov.

1.92

 

1900

Mar.

5.66

    N.A.

       N.A. 

 

1899

Apr.

3.08

Oct.

0.25

 

1898

Mar.

3.41

Nov.

0.08

 

1897

Apr.

8.16

Nov.

2.25

 

1896

Feb.

7.75

Nov.

2.91

 

1895

Jan.

12.25

Nov.

2.58

 

1894

Mar.

8.66

Nov.

2.50

 

1893

Mar.

9.70

Nov.

2.83

 

1892

May

5.08

Nov.

1.75

 

1891

Apr.

6.47

Nov.

2.35

 

1890

Jan.

13.66

Nov.

3.25

 

1889

Apr.

5.88

Oct.

2.88

 

1888

Mar.

4.86

Nov.

1.56

 

1887

Mar.

5.42

Dec.

1.82

 

1886

Jan.

8.94

Dec.

3.08

 

1885

Jan.

6.02

Oct.

1.41

 

1884

Apr.

5.58

Dec.

1.41

 

1883

May

4.12

Nov.

1.47

 

1882

Mar.

6.16

Nov.

2.39

 

1881

Feb.

10.25

Nov.

3.08

 

1880

Apr.

10.08

Nov.

3.83

 

1879

Mar.

8.31

Nov.

3.56

 

1878

Mar.

12.39

Jan.

1.95

 

1877

Mar.

5.64

Oct.

1.77

 

1876

Mar.

12.37

Jan.

3.71

 

1875

Feb.

6.60

Nov.

1.75

 

1874

Mar.

8.62

Oct.

3.41

 

1873

 

 

Nov.

1.08

 




8/11/08