Lost River Pool (Klamath)

Reachcode: 18010204002206 | Area: 203.8 acres | Shoreline: 9.9 mi | View on Interactive Map

(From Atlas of Oregon Lakes, Johnson et al. 1985)  Lost River Reservoir is an impoundment on the Lost River which serves as a vital component of the Bureau of Reclamation's Klamath Project. The Project is an interstate agreement which provides for the beneficial use of water resources in the Klamath Basin. The annual yield of Lost River is used as the principal source of water for irrigation of more than 200,000 acres of land both in Oregon and California. The river originates with the outflow of Clear Lake Reservoir in Modoc County, California, and discharges ultimately into Tule Lake, California. It thus constitutes a naturally closed basin. Historically, Tule Lake was a large natural sump, which would rise during periods of high runoff and slowly recede during summer and fall due to evaporation. One of the first facilities built in the Klamath Project was the Lost River Diversion Dam and a canal connecting the Lost and Klamath Rivers. Since completion in 1912, this facility has provided for the diversion of Lost River flood flows into the Klamath River and allowed reclamation of the bed of Tule Lake.

Lost River is a shallow, sluggish stream which enters Oregon through the Langell Valley. During its course through Langell Valley, the river disappears for several miles; hence its name. Miller Creek is the largest tributary, entering from the east after regulation in Gerber Reservoir. Near the town of Bonanza the river turns to the west. In this area several large springs contribute to the flow. After flowing through Olene Gap, the water is controlled by the Lost River Diversion Dam. Below the dam, the river is essentially a canal during the irrigation season. The contributing drainage basin includes a large amount of irrigated land which significantly depletes the natural flow. That portion of the basin not in irrigated land is mostly rangeland and there are some forested areas at higher elevations.

Lost River Reservoir is one of the saltier lakes in Oregon, although it is not considered a sump, or an evaporation basin, because of irrigation withdrawals. However, because of the extensive evaporation in the basin, the concentrations of ions are rather high, and conductivity is well above average for eastern Oregon reservoirs. Both alkalinity and pH are also rather high. The concentration of phosphorus in the lake is sufficient to support active growth of algae. Algal blooms appear frequently and the chlorophyl concentrations indicate eutrophic conditions. Water transparency is very limited because of the growth of algae and the presence of inorganic turbidity; there are extensive growths of submerged and emergent macrophytes in the reservoir. The active growth of algae and macrophytes supports a productive food chain, and the reservoir has a popular warm water fishery. By all indications it is classified as eutrophic.

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The list below includes results of zebra and quagga mussels surveys conducted by the Center for Lakes and Reservoirs and other agencies. The results "non-detect" and "results pending" indicate that surveys for zebra and quagga mussels were conducted, but none were detected or results are pending. For more details on zebra and quagga mussel monitoring, please visit the Online Mussel Monitoring Map.

Date Status/Species Source
July 24, 2012 non detect Portland State University

The list of plants below includes results of aquatic plant surveys conducted by the Center for Lakes and Reservoirs as well as aquatic invasive plant species detections that have been reported to iMap Invasives: an online, GIS-based invasive species reporting and querying tool.

Plants listed in the table below are categorized as native to Oregon, on the Oregon Department of Agriculture’s (ODA’s) Noxious Weed List, on the Federal Noxious Weed List, or non-native but not listed as noxious. Federal Noxious Weed List plants are plants determined by USDA to be serious threats to U.S. agriculture, irrigation, navigation, public health or the environment (7 C.F.R. 360.200). The ODA Noxious Weed categories are:

ODA Class A - weeds either unknown or with small enough infestations to make eradication or containment possible; targeted for eradication or intensive control.

ODA Class B - regionally abundant weeds (may have limited distribution in some counties); targeted for local/regional control on case-by-case basis.

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Date Species Status Source
July 14, 2014 Typha latifolia (common cat-tail) Native CLR
July 14, 2014 Elodea canadensis (common elodea, Canadian waterweed) Native CLR
July 14, 2014 Najas flexilis (common naiad) Native CLR
July 14, 2014 Ceratophyllum demersum (Coontail; hornwort) Native CLR
July 14, 2014 Potamogeton crispus (curly leaf pondweed) Non-native CLR
July 14, 2014 Lemna sp. (duckweed) Native CLR
July 14, 2014 Spirodela polyrrhiza (great duckweed) Native CLR
July 14, 2014 Schoenoplectus acutus (hardstem bulrush) Native CLR
July 14, 2014 Zannichellia palustris (horned pondweed) Native CLR
July 14, 2014 Myriophyllum hybrid (hybrid of Eurasian and northern milfoils) Non-native CLR
July 14, 2014 Potamogeton foliosus (leafy pondweed) Native CLR
July 14, 2014 Potamogeton richardsonii (Richardson's pondweed) Native CLR
July 14, 2014 Stuckenia pectinata (sago pondweed) Native CLR