Our new Biological Assessment is out - Klamath Basin Crisis

Klamath Project Operations Biological Assessment
Endangered Suckers: Environmental Baseline for Suckers
1981; Forbes et al. 1998; Geiger et al. 2005). Most parameters exhibited
substantial seasonal variations. On a study-wide basis, however, phosphorus,
inorganic nitrogen, and chlorophyll-a concentrations were similar to lake water.
The results of this study do not address the flux of material between the pelagic
and littoral zones. Some of the data suggest, however, that pelagic conditions
influence the outer areas of Hanks Marsh. Conversely, processes within the
marsh may form water quality gradients that extend into the pelagic zone.
It’s likely that the physical and chemical characteristics of large lakeshore
marshes around UKL historically played an important role in nutrient cycling,
regulating the algal community and other characteristics of the system. Littoral
wetlands in UKL have been drastically reduced in size due to agricultural
reclamation. However, approximately 17,000 acres of drained wetlands are in the
process of being restored to littoral wetlands, which may improve the lake’s
ability to regulate the algal community.
Water Quality in the Klamath River from Lake Ewauna to Keno Dam
The Lake Ewauna to Keno reach of the Klamath River (Link River to Keno Dam)
is approximately 29 km (18 miles) long and 90 to 790 m (300 to 2,600 feet) wide;
maximum depths range from 2.7 to 6 m (9 to 20 feet). Summer water quality is
extremely poor, with heavy AFA growth, low DO concentrations, and high pH
and water temperature (CH2M Hill 1995; NRC 2004; Deas and Vaughn 2006;
Reclamation, unpublished data).
The Klamath River, from source to mouth, is listed as water quality impaired (by
both Oregon and California) under Section 303(d) of the Federal Clean Water Act
(CWA). In 1992, the California State Water Resources Control Board proposed
that the Klamath River be listed under the CWA as impaired for both temperature
and nutrients, requiring the development of TMDL limits and implementation
plans. U.S. Environmental Protection Agency (EPA) and the North Coast
Regional Water Quality Control Board accepted this action in 1993. The basis for
listing the Klamath River as impaired was aquatic habitat degradation due to
excessively warm summer water temperatures and algae blooms associated with
high nutrient loads, water impoundments, and agricultural water diversions.
However, the Klamath River has probably historically always been a relatively
warm river (Hecht and Kamman 1996).
The Lake Ewauna to Keno reach of the Klamath River experiences seasonal poor
water quality during summer months with water temperature exceeding 25ºC, pH
approaching 10 units, dense agal blooms dominated by AFA, and DO
concentrations below 4 mg/L (hypoxia). Like UKL, dense blooms of AFA affect
the water quality within the Lake Ewauna to Keno reach of the Klamath River.
However, the AFA blooms are typically less intense and are spatially and
temporally move variable than those observed in UKL (Reclamation, unpublished
data). Persistent hypoxic events establish in this reach of the Klamath River and
can last for several days or even weeks where the DO will remain less than 4
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