Snettisham Hydroelectric Project
The Snettisham hydroelectric power plant is a 78 MW power plant located 28 miles south of central Juneau, Alaska and accessible only by boat or seaplane. The power plant is fed by two lakes that are tapped from below, negating the need for a traditional dam. As of December 2017 it supplies 78% of the electricity for Alaska Electric Light & Power. It is connected to Juneau by a 44-mile transmission line.
It was completed in 1973.
Climate
| Climate data for Snettisham Power Plant, Alaska, 1991–2020 normals, 2003–2023 extremes: 29ft (9m) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °F (°C) | 47 (8) |
49 (9) |
57 (14) |
66 (19) |
81 (27) |
88 (31) |
90 (32) |
87 (31) |
77 (25) |
65 (18) |
55 (13) |
51 (11) |
90 (32) |
| Mean maximum °F (°C) | 41.7 (5.4) |
42.2 (5.7) |
48.1 (8.9) |
59.2 (15.1) |
72.6 (22.6) |
79.5 (26.4) |
78.7 (25.9) |
78.2 (25.7) |
69.3 (20.7) |
57.8 (14.3) |
45.7 (7.6) |
41.6 (5.3) |
83.4 (28.6) |
| Mean daily maximum °F (°C) | 30.3 (−0.9) |
33.0 (0.6) |
38.0 (3.3) |
48.1 (8.9) |
57.5 (14.2) |
63.0 (17.2) |
63.4 (17.4) |
62.6 (17.0) |
55.8 (13.2) |
46.3 (7.9) |
36.2 (2.3) |
31.0 (−0.6) |
47.1 (8.4) |
| Daily mean °F (°C) | 26.1 (−3.3) |
28.0 (−2.2) |
31.7 (−0.2) |
40.1 (4.5) |
47.7 (8.7) |
54.4 (12.4) |
56.5 (13.6) |
56.0 (13.3) |
50.4 (10.2) |
41.7 (5.4) |
32.4 (0.2) |
27.3 (−2.6) |
41.0 (5.0) |
| Mean daily minimum °F (°C) | 21.9 (−5.6) |
23.1 (−4.9) |
25.5 (−3.6) |
32.1 (0.1) |
37.9 (3.3) |
45.8 (7.7) |
49.6 (9.8) |
49.4 (9.7) |
44.9 (7.2) |
37.1 (2.8) |
28.6 (−1.9) |
23.5 (−4.7) |
35.0 (1.7) |
| Mean minimum °F (°C) | 5.0 (−15.0) |
8.3 (−13.2) |
12.5 (−10.8) |
24.6 (−4.1) |
31.7 (−0.2) |
39.5 (4.2) |
44.4 (6.9) |
43.6 (6.4) |
36.8 (2.7) |
29.0 (−1.7) |
16.6 (−8.6) |
9.5 (−12.5) |
0.4 (−17.6) |
| Record low °F (°C) | −11 (−24) |
−6 (−21) |
−7 (−22) |
16 (−9) |
23 (−5) |
34 (1) |
40 (4) |
40 (4) |
33 (1) |
19 (−7) |
0 (−18) |
−2 (−19) |
−11 (−24) |
| Average precipitation inches (mm) | 18.56 (471) |
14.88 (378) |
10.90 (277) |
8.99 (228) |
8.31 (211) |
6.85 (174) |
10.24 (260) |
13.99 (355) |
27.01 (686) |
28.90 (734) |
21.08 (535) |
19.98 (507) |
189.69 (4,816) |
| Average snowfall inches (cm) | 50.2 (128) |
44.9 (114) |
35.9 (91) |
4.7 (12) |
0.1 (0.25) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
2.6 (6.6) |
31.0 (79) |
47.8 (121) |
217.2 (551.85) |
| Average extreme snow depth inches (cm) | 48.9 (124) |
61.8 (157) |
65.4 (166) |
50.7 (129) |
23.4 (59) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
2.0 (5.1) |
16.5 (42) |
33.6 (85) |
71.8 (182) |
| Average precipitation days (≥ 0.01 in) | 21.4 | 16.9 | 15.8 | 18.0 | 15.4 | 18.4 | 18.8 | 20.2 | 21.6 | 23.9 | 19.9 | 20.5 | 230.8 |
| Average snowy days (≥ 0.1 in) | 13 | 11 | 9 | 3 | 0 | 0 | 0 | 0 | 0 | 1 | 9 | 14 | 60 |
| Source 1: NOAA | |||||||||||||
| Source 2: XMACIS2 (extremes & 2003-2023 snow) | |||||||||||||