The Reclamation Act of 1902 (43 U.S.C. 391 et seq.) authorized the Secretary of the Interior to locate, construct, operate, and maintain works for the storage, diversion, and development of water, for the reclamation of arid and semiarid lands in the western states.
Congress facilitated development of the Klamath Project by authorizing the Secretary to (a) raise or lower the level of the Lower Klamath and Tule Lakes; and (b) dispose of the land uncovered by such operations for use under the Reclamation Act of 1902. Starting around 1912, construction and operation of the numerous facilities associated with the Bureau of Reclamation’s (Reclamation) Klamath Project significantly altered the natural flows of the upper and lower Klamath River. Reclamation’s Klamath Project consists of an extensive system of canals, pumps, diversion structures, and dams capable of routing water to approximately 200,000 acres (81,000 hectares) of irrigated farmlands in the upper Klamath Basin. Water diversions from Upper Klamath Lake for the Klamath Project affects river flows downstream of the Link River and Iron Gate dams.
Documents and References
- Klamath Project Biological Opinions
- Klamath Project Reports
Iron Gate Dam Flows
Reclamation currently manages flows in the Klamath River in a manner that resembles the rates of flow that would be present in the river with no dams or diversions, which is called natural hydrograph. This natural hydrograph is represented by real-time climate and hydrological conditions. Daily target flows for Iron Gate Dam are calculated using equations developed in coordination with NOAA Fisheries and the U.S. Fish and Wildlife Service (USFWS). These equations include the following hydrologic variables:
- Upper Klamath Lake storage,
- Upper Klamath Lake net inflow,
- The Natural Resources Conservation Services’ (NRCS) upper Klamath Lake inflow forecasts, and
- Tributary accretions downstream of Link River Dam.
Generally, wetter hydrologic conditions in the upper Klamath Basin result in larger flows in the mainstem Klamath River; whereas drier hydrologic conditions in the upper Klamath Basin result in lower flows in the mainstem Klamath River below Iron Gate Dam.
Fall/Winter Operations (October through February)
Water management in fall and winter employs a formulaic management approach focused on maintaining conditions in upper Klamath Lake and the Klamath River, to meet the needs of coho salmon and suckers and provide water deliveries to the Klamath Project and Lower Klamath National Wildlife Refuge. This approach is designed to ensure appropriate water storage and sucker habitat in upper Klamath Lake, while providing flows that represent current conditions in the upper Klamath Basin and meet the needs of ESA-listed species downstream of Iron Gate Dam.
Spring/Summer Operations (March through September)
Water management in spring and summer also employs a formulaic approach focused on maintaining conditions in upper Klamath Lake and the Klamath River to meet the needs of coho salmon and suckers and provide water deliveries to the Klamath Project and Lower Klamath National Wildlife Refuge.
The Environmental Water Account (EWA) is the volume of water available to the Klamath River from upper Klamath Lake for use from March through September. EWA volumes were developed with consideration of the needs of coho salmon, including effects to their critical habitat. EWA is calculated monthly from March through June based on hydrologic conditions, including upper Klamath Lake storage, upper Klamath Lake net inflow, and NRCS’ upper Klamath Lake inflow forecasts.
Distribution of EWA is based on equations that use upper Klamath Lake net inflow as a hydrologic indicator to determine Link River dam releases. Link River Dam releases and tributary accretions below Link River Dam comprise the total flow released at Iron Gate Dam.
Proposed Minimum Flows at Iron Gate Dam
Regardless of hydrologic conditions, daily average minimum flows at Iron Gate Dam must be met or exceeded to meet the needs of coho salmon in the Klamath River and are defined in the table below. Further details of how Iron Gate Dam flows are calculated in Fall/Winter Operations and how the Environmental Water Account is determined and distributed in Spring/Summer Operations is described in the 2019 Biological Opinion for the Klamath Project.
Iron Gate Dam daily average minimum flows
|Month||Cubic feet per second (cfs)|
Minimization Measures and Monitoring
In an effort to minimize the adverse effects of the Klamath Project, Reclamation will provide $700,000 annually in 2019 and 2020, and $500,000 from 2021 through 2023, for program administration and projects that address limiting factors for Southern Oregon/Northern California Coast coho salmon in the Klamath Basin, contingent upon Reclamation’s annual budget process and appropriations.
The program targets projects that are likely to have the greatest impact on promoting survival and recovery and that provide sustainable and lasting ecological benefits in the Klamath River Basin for coho salmon. Highest priority will be given to projects that include:
- Improve fish passage and remove barriers,
- Improve coho habitat and access to coldwater refugia,
- Instream coho habitat enhancement and protections, and
- Water conservation.
Restoration projects minimize habitat related effects of the Klamath Project by individually and comprehensively improving critical habitat conditions for coho salmon individuals, populations, and the species overall.
Habitat restoration projects funded by Reclamation are designed and implemented consistent with techniques and minimization measures presented in California Department of Fish and Wildlife’s (CDFW) California Salmonid Stream Habitat Restoration Manual, Fourth Edition, Volume II (Part IX: Fish Passage Evaluation at Stream Crossings, Part XI: Riparian Habitat Restoration, and Part XII: Fish Passage Design and Implementation; Flosi et al. 2010, referred to as the Restoration Manual).
Restoration activities funded by Reclamation include, but are not limited to, the following:
- Instream habitat structures and improvements,
- Barrier modification for fish passage,
- Bioengineering and riparian habitat restoration,
- Removal of small dams (permanent and flashboard),
- Creation of off-channel/side channel habitat,
- Developing alternative stock-water supply, tail-water collection ponds, water storage tanks, piping ditches, and fish screens, and
- Installing headgates/water measuring devices.
Ceratomyxosis, which is caused by Ceratonova shasta, has been identified as the most significant disease for juvenile salmon in the Klamath Basin. To minimize Klamath Project-related effects on disease prevalence in the Klamath River, the Bureau of Reclamation funds for (1) the weekly monitoring of C. shasta actinospore (including genotype II) concentrations in the mainstem Klamath River immediately upstream of Beaver Creek during mid-April to June, and (2) the annual monitoring of the percent of C. shasta infection rates for Chinook salmon in the mainstem between the Shasta River and the Trinity River during the months of May to July.
Additional information about C. shasta in the Klamath River can be found on the USFWS California-Nevada Fish Health Center webpage.
The Klamath Basin and Climate Change
The following climate prediction, hydrology/river forecasting, and climate change preparation resources include and/or reference the Klamath Basin:
National Weather Service Climate Prediction Center: For seasonal forecasting, El Niño Southern Oscillation advisories, and U.S. drought monitoring information
National Weather Service California Nevada River Forecast Center: For hydrology, U.S./regional seasonal and monthly drought monitoring, and soil moisture information
ClimateWise: For information on Climate Change Preparation in the Klamath Basin
Preparing for Climate Change in the Klamath Basin (March 2010): A report by the National Center for Conservation Science & Policy and The Climate Leadership Initiative