Copco Lake

Copco Lake was an artificial lake on the Klamath River in Siskiyou County, California, near the Oregon border. The lake's waters were impounded by the Copco Number 1 Dam, which was completed in 1922 as part of the Klamath River Hydroelectric Project.

Copco Lake
Copco Lake Show map of California Copco Lake Show map of the United States
Location	Siskiyou County, California^[1]
Coordinates	41°58′46″N 122°18′13″W / 41.97944°N 122.30361°W / 41.97944; -122.30361^[1]
Type	reservoir
Primary inflows	Klamath River, Beaver Creek, Raymond Gulch, Spannaus Gulch, Snackenburg Creek, Milk Creek, Parks Canyon, Indian Creek,
Primary outflows	Klamath River^[2]
Catchment area	4,300 square miles (11,000 km^2)^[2]
Basin countries	United States
Max. length	3 miles (4.8 km)
Max. width	1,200 yards (1,100 m)
Surface area	1,000 acres (400 ha)^[2]
Average depth	77 feet (23 m)
Water volume	77,000 acre-feet (95,000,000 m^3)^[2]
Surface elevation	2,605 feet (794 m)^[1]

The dam was breached in January 2024 as a component of the Klamath River Renewal Project following decades of activism from the Un-Dam the Klamath movement. The dam structure is planned to be fully removed by the end of 2024.

History

Copco Lake was created by the construction of Copco Number 1 Dam. This dam was completed in 1922 by the California Oregon Power Company (COPCO).^[2] COPCO was merged into Pacific Power and Light in 1961, and is now known as Pacificorp.^[3]

Dam removal

Copco Number 1 and Number 2 Dams were two of the four dams in the Klamath River Hydroelectric Project which were removed in the 2020s as part of the Klamath River Renewal Project. The social movement to Un-Dam the Klamath had been ongoing for over 20 years.^{[4][5][6][7][8]}

As of February 2016, the states of Oregon and California, the dam owners, federal regulators and other parties had reached an agreement to remove all four dams by the year 2020, pending approval by the Federal Energy Regulatory Commission (FERC).^[9] The plan was delayed in 2020 due to conditions placed on the project by FERC.^[10] In February 2022, the FERC released their final Environmental Impact Statement (EIS) on the dam's removal,^[11] and the dam was slated for removal in 2024.^[12] Copco 2 was demolished in 2023.

On January 23, 2024, the drawdown of water and sediment from Copco Lake was initiated via a detonation at the foot of Copco Number 1 Dam. The lake was expected to take three to four weeks to fully drain, at which point crews will plant native vegetation along the emerged riverbank. This was the final of the four dams to be breached as part of the Klamath River Renewal Project. Removal of the dam structure began in March 2024.^[13][14]

Recreation

The lake was used for kayaking, fishing, swimming, windsurfing, power boating, and sailing. The surrounding area had facilities for picnicking and hiking.^[15] In the summer months, the lake often experienced large blooms of toxic cyanobacteria rendering the water unsafe for human contact or consumption.^[16]

Dams

Copco Number 1 Dam

Copco Number 1 Dam
Country	United States
Location	Siskiyou County, California
Coordinates	41°58′48″N 122°20′04″W / 41.98000°N 122.33444°W / 41.98000; -122.33444
Opening date	1922
Owner(s)	PacifiCorp
Dam and spillways
Type of dam	Gravity
Impounds	Klamath River^[2]
Height	132 feet (40 m)^[2]
Length	415 feet (126 m)^[2]
Elevation at crest	2,613 feet (796 m)^[2]
Width (crest)	9 feet (2.7 m)^[2]
Dam volume	70,312 cubic yards (53,757 m^3)^[2]
Reservoir
Creates	Copco Reservoir
Total capacity	77,000 acre-feet (95,000,000 m^3)^[2]
Catchment area	4,300 square miles (11,000 km^2)^[2]
Maximum length	3 miles (4.8 km)
Maximum width	1,200 yards (1,100 m)

Copco Number 1 Dam (National ID CA00323) is a gravity dam 415 feet (126 m) long and 132 feet (40 m) high, with 19.5 feet (5.9 m) of freeboard. PacifiCorp owned the dam prior to its transfer to the Klamath River Renewal Corporation in 2022.^[17] The dam is scheduled to be demolished in 2024 as part of the Klamath River Renewal Project.^[18]

Copco Number 2 Dam

Copco Number 2 Dam was a gated diversion dam located just below Dam No. 1. The dam diverted most of the flow of the river, about 2,400 to 2,500 cu ft/s (68 to 71 m³/s), through a flume and tunnels to a 27 megawatt powerhouse 1.5 miles (2.4 km) downstream, on the upstream end of Iron Gate Reservoir. The diversion bypassed a canyon section of the Klamath River that historically consisted of some steep rapids. The dam was required to maintain a minimum release of 10 cu ft/s (0.28 m³/s) to prevent this stretch from being entirely dewatered. Because it had no effective storage capacity, Dam No. 2 depended entirely on the regulated flows released from Copco Lake.^[19] The dam was demolished in 2023 during the Klamath River Renewal Project.^[20]

See also

• List of dams and reservoirs in California
• List of lakes in California

References

1. "Copco Lake". Geographic Names Information System. United States Geological Survey, United States Department of the Interior.
2. "Dams Within the Jurisdiction of the State of California (A-G)" (PDF). California Department of Water Resources, Division of Safety of Dams. Retrieved December 21, 2012.
3. "California Oregon Power Company or COPCO" (PDF). Retrieved December 21, 2012.
4. Hartel, Diana (25 May 2011). "Doctor's Orders: Undam the Klamath". High Country News. from the original on 2011-05-18.
5. "Dams Are Threatening California Salmon and a Native Tribe's Culture". VICE News. 22 October 2020. from the original on 2020-10-23.
6. "Klamath River Dam and Sediment Investigation" (PDF). Gathard Engineering Consulting. November 2006. Retrieved December 21, 2012.
7. Fimrite, Peter (September 30, 2009). "Deal to raze 4 Klamath dams". San Francisco Chronicle. Retrieved December 21, 2012.
8. Aschbrenner, Joel (Mar 8, 2012). "Copco Lake: Homeowners worry as property values drop". Herald and News. Retrieved December 21, 2012.
9. "New plan to remove Klamath River dams without help from Congress". 3 February 2016.
10. "Agency throws curveball in largest US dam demolition plan along Oregon border". The Associated Press. Jul 17, 2020. Retrieved 20 Jul 2020.
11. "FERC Staff Issues the Draft Environmental Impact Statement for the Hydropower License Surrender and Decommissioning of the Lower Klamath Project No. 14803 (P-14803-001)". www.ferc.gov. Federal Energy Regulatory Commission. Retrieved 2022-04-30.
12. "Major hurdle cleared in plan to demolish 4 Klamath River dams". opb. Retrieved 2022-04-30.
13. Neumann, Erik (24 January 2024). "Fourth dam breached on the Klamath River". opb. Retrieved 8 February 2024.
14. https://www.usatoday.com/story/news/nation/2024/05/12/demolition-starts-iron-gate-dam-klamath-river-dams/73647405007/
15. "Copco lake - Kayaking". Retrieved December 21, 2012.
16. "Trying to Tame the Klamath River Filled It with Toxic Algae". Scientific American. Retrieved August 10, 2020.
17. https://klamathrenewal.org/ferc-approves-license-surrender-and-decommissioning-of-the-lower-klamath-project-dams/
18. "WORld's LARGEST SALMON RESTORATION PROJECT UNDERWAY – Klamath River Renewal".
19. "Copco No. 2: The dam produces power but no irrigation water". 16 February 2012.
20. "Work on Copco No. 2 Dam Removal Comes to a Close – Klamath River Renewal".

External links

• page at county website bad link
• COPCO LAKE Five Year Photos KLAMATH RIVER KLAMATH DAMS