Island Park Dam

Last updated
Island Park Dam
Islandparkdam.jpg
USA Idaho relief location map.svg
Red pog.svg
Location of Island Park Dam in Idaho
Location Fremont County, Idaho, near Island Park, Idaho
Coordinates 44°25′06.92″N111°23′47.50″W / 44.4185889°N 111.3965278°W / 44.4185889; -111.3965278
Construction began1937
Opening date1939
Operator(s) U.S. Bureau of Reclamation
Dam and spillways
Type of dam Zoned earthfill dam
Impounds Henrys Fork
Height94 ft (29 m)
Length9,500 ft (2,900 m)
Spillway typeUngated bathtub
Reservoir
CreatesIsland Park Reservoir
Total capacity135,205 acre-feet (0.166773 km3)
Catchment area 482 sq mi (1,250 km2) [1]

Island Park Dam is operated by the U.S. Bureau of Reclamation in Fremont County, Idaho, United States. The dam lies in Targhee National Forest near Island Park. The zoned earthfill dam was built between 1937 and 1939 as part of the Minidoka Project, which provides water to irrigate farmland in Idaho's Snake River Plain. [1]

Contents

The dam provides only water storage, impounding 135,000 acre-feet (0.167 km3), which is distributed by the Cross Cut Canal to farms in Fremont and Madison counties in Idaho, and Teton County in Wyoming. [1] The Island Park and Grassy Lake reservoirs were built as an alternative to construction of a larger project that would have flooded the Fall River area of Yellowstone National Park. [2] [3]

Climate

Island Park Dam has a humid continental climate (Köppen Dfb) bordering upon a subalpine climate (Dfc). Summers feature very warm afternoons and chilly mornings, whilst winters are freezing and very snowy with an annual snowfall averaging 214 inches or 5.44 metres and reaching 375 inches or 9.53 metres between July 1974 and June 1975. The dam's weather recording site holds the record for the eighth-lowest temperature recorded in the United States (and lowest temperature recorded in Idaho) at −60 °F or −51.1 °C.

Climate data for Island Park Dam, Idaho
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Record high °F (°C)49
(9)
55
(13)
62
(17)
76
(24)
84
(29)
91
(33)
97
(36)
96
(36)
91
(33)
82
(28)
68
(20)
56
(13)
97
(36)
Mean maximum °F (°C)40
(4)
44
(7)
52
(11)
64
(18)
75
(24)
82
(28)
87
(31)
88
(31)
82
(28)
71
(22)
54
(12)
41
(5)
88
(31)
Mean daily maximum °F (°C)26.5
(−3.1)
31.6
(−0.2)
38.5
(3.6)
48.4
(9.1)
59.8
(15.4)
68.8
(20.4)
79.0
(26.1)
78.5
(25.8)
68.7
(20.4)
54.9
(12.7)
37.2
(2.9)
27.6
(−2.4)
51.6
(10.9)
Mean daily minimum °F (°C)3.0
(−16.1)
4.8
(−15.1)
10.5
(−11.9)
21.5
(−5.8)
31.1
(−0.5)
37.7
(3.2)
42.9
(6.1)
40.7
(4.8)
32.8
(0.4)
25.1
(−3.8)
14.9
(−9.5)
5.6
(−14.7)
22.6
(−5.2)
Mean minimum °F (°C)−28
(−33)
−25
(−32)
−16
(−27)
3
(−16)
19
(−7)
27
(−3)
33
(1)
30
(−1)
22
(−6)
11
(−12)
−9
(−23)
−23
(−31)
−33
(−36)
Record low °F (°C)−60
(−51)
−47
(−44)
−36
(−38)
−18
(−28)
7
(−14)
20
(−7)
25
(−4)
17
(−8)
8
(−13)
−6
(−21)
−34
(−37)
−51
(−46)
−60
(−51)
Average precipitation inches (mm)3.80
(97)
2.93
(74)
2.48
(63)
2.03
(52)
2.49
(63)
2.71
(69)
1.25
(32)
1.45
(37)
1.50
(38)
1.89
(48)
2.56
(65)
3.55
(90)
28.64
(728)
Average snowfall inches (cm)48.6
(123)
37.5
(95)
29.3
(74)
13.9
(35)
4.1
(10)
0.4
(1.0)
0.0
(0.0)
0.1
(0.25)
1.0
(2.5)
6.6
(17)
25.3
(64)
47.9
(122)
214.7
(543.75)
Average precipitation days1512119101067671013116
Source 1: Western Regional Climate Center [4]
Source 2: National Oceanic and Atmospheric Administration [5]

References

  1. 1 2 3 "Island Park Dam". Bureau of Reclamation. Archived from the original on 26 September 2012. Retrieved 4 May 2011.
  2. Haines, Aubrey L. (1996). The Yellowstone Story: A History of Our First National Park. University Press of Colorado. p. 346. ISBN   0-87081-390-0.
  3. Yochim, Michael J. "Conservationists and the Battles to Keep Dams Out of Yellowstone: Hetch Hetchy Overturned" (PDF): 299.{{cite journal}}: Cite journal requires |journal= (help)
  4. "ISLAND PARK, IDAHO". Western Regional Climate Center. Retrieved January 12, 2016.
  5. "ISLAND PARK, IDAHO". NOAA. Retrieved June 1, 2023.