Swift Dam (Montana)

Swift Dam (National Inventory of Dams ID MT00581) is a dam in Pondera County, Montana, United States, on the southern end of the Blackfeet Indian Reservation.

The dam at was originally constructed around 1910, with a height of 157 feet (48 m).[1] The embankment structure gave way on June 10, 1964, after heavy rains caused flooding on Birch Creek. The dam collapsed and sent a 30-foot (9.1 m) wall of water down the creek bed. The nearby dam at Lower Two Medicine Lake also failed, and at least 28 people were killed.[2]

The current concrete-arch structure was completed in 1967, with a height of 205 feet (62 m), and a length at its crest of 573 feet (175 m).[3] The reservoir is also contained by a secondary earthen dike (National Inventory of Dams ID MT00580) with a height of 53 feet (16 m) and a length of 457 feet (139 m), also completed in 1967. The dams and reservoir are owned and operated by the local Pondera Canal & Reservoir Company.[4]

The reservoir, Swift Reservoir, has a maximum storage capacity of 34,000 acre-feet (42,000,000 m3), normal storage of 30,000 acre-feet (37,000,000 m3),[3] and a normal elevation of 4,890 feet (1,490 m).[5] Recreation is restricted to hiking in the area, with a parking area that requires Blackfeet Nation permission.

References

  1. ^ "Montana Film Office - Dam Photos". Archived from the original on 2012-04-01. Retrieved 2012-09-20.
  2. ^ "Torrents of rain, miles of misery: 1964".
  3. ^ a b http://ce-npdp-serv2.stanford.edu/DamDirectory/DamDetail.jsp?npdp_id=MT00581[permanent dead link‍]
  4. ^ "History | Pondera County Canal Company". Archived from the original on 2014-08-26. Retrieved 2012-09-20.
  5. ^ U.S. Geological Survey Geographic Names Information System: Swift Dam (Montana)

48°09′47″N 112°52′19″W / 48.16306°N 112.87192°W / 48.16306; -112.87192