Data is updated every year about October/November time period



Mansfield Hollow Dam, Natchaug River
Peak Pool Levels
by Water Year
(1952 - Present)
Drainage Area:  159 sq. miles
Normal Pool:  16.5 ft. (Summer), 15 ft. (Winter)
Gate Invert Elev.:  195 ft. NGVD
1" Runoff =   8,480 ac-ft
Storage at Spillway Crest:   5.8 in. / 52,000 ac-ft



Date
Annual Peak
Pool Level (ft)
Storage Utilized
Inches Acre-Feet Percent
02 Jun 1952 14.8 0.0 0 0
26 Jan 1953 19.0 0.1 1,180 2
13 Sep 1954 31.3 1.1 9,440 19
22 Aug 1955 51.8 3.8 31,920 65
18 Oct 1955 37.2 1.7 14,640 30
26 Jan 1957 22.5 0.4 3,145 6
29 Jan 1958 22.8 0.4 3,328 7
05 Apr 1959 29.8 1.0 8,240 17
     
01 Apr 1960 17.5 0.1 440 1
27 Feb 1961 26.0 0.6 5,430 11
02 Apr 1962 16.1 0.0 0 0
09 Oct 1962 23.0 0.4 3,450 7
01 Feb 1964 15.5 0.0 0 0
15 Apr 1965 18.3 0.1 830 2
26 Mar 1966 19.5 0.2 1,445 3
28 May 1967 29.8 1.0 8,240 17
20 Mar 1968 37.6 1.8 15,020 31
27 Mar 1969 25.7 0.6 5,226 11
     
12 Feb 1970 36.0 1.6 13,500 27
13 Sep 1971 18.3 0.1 830 2
04 Mar 1972 34.3 1.4 11,970 24
04 Feb 1973 30.3 1.0 8,640 18
22 Dec 1973 31.5 1.1 9,600 20
06 Jun 1975 20.1 0.2 1,759 4
29 Jan 1976 34.4 1.4 12,060 25
15 Mar 1977 25.1 0.6 4,818 10
28 Jan 1978 39.8 2.0 17,240 35
27 Jan 1979 44.9 2.7 22,880 47
     
23 Mar 1980 37.2 1.7 14,640 30
26 Feb 1981 34.0 1.4 11,700 24
08 Jun 1982 52.6 3.9 33,100 67
26 Apr 1983 41.6 2.3 19,160 39
04 Jun 1984 48.7 3.3 27,610 56
14 Jun 1985 19.9 0.2 1,657 3
28 Jan 1986 30.2 1.0 8,560 17
07 Apr 1987 46.8 3.0 25,200 51
28 Mar 1988 22.9 0.4 3,389 7
15 Aug 1989 32.3 1.2 10,240 21
     
23 Oct 1989 35.0 1.5 12,600 26
15 Oct 1990 24.7 0.5 4,549 9
25 Nov 1991 24.6 0.5 4,482 9
02 Apr 1993 36.5 1.6 13,975 28
03 Feb 1994 29.4 0.9 7,920 16
10 Mar 1995 23.5 0.4 3,765 8
18 Apr 1996 37.3 1.7 14,773 30
19 Dec 1996 23.0 0.4 3,432 7
11 Mar 1998 42.6 2.4 20,260 41
20 Jan 1999 24.7 0.5 4,549 9
     
23 Apr 2000 29.4 0.9 7,936 16
18 Jun 2001 28.4 0.8 7,165 15
14 May 2002 21.8 0.3 2,718 6
27 May 2003 25.0 0.6 4,770 10
15 Apr 2004 30.2 1.0 8,560 17
04 Apr 2005 27.8 0.8 6,800 14
17 Oct 2005 43.7 2.5 21,750 44
18 Apr 2007 38.0 1.8 15,400 31
10 Mar 2008 32.7 1.2 10,560 21
14 Dec 2008 37.4 1.7 14,830 30
     
01 Apr 2010 45.3 2.8 23,360 48
08 Mar 2011 38.2 1.8 15,600 31
09 Dec 2011 22.0 0.3 2,840 6
09 Jun 2013 29.1 0.9 7,720 15
01 Apr 2014 30.1 1.0 8,496 17
22 Apr 2015 22.3 0.4 2,993 6
26 Feb 2016 21.3 0.3 2,411 5
02 Apr 2017 22.4 0.4 3,090 6
14 Jan 2018 28.1 0.8 9,722 19
26 Jan 2019 29.4 0.9 10,700 21
     
15 Dec 2019 22.4 0.4 5,928 11
11 Jul 2021 40.9 2.2 21,216 41