Information About the Klamath River in California - From the University of California at Davis, CA

Upper Klamath:

http://endeavor.des.ucdavis.edu/newcara/basin.asp?cara_id=7

General Information Basin Name: Upper Klamath (CA & OR) Area: 544215.51 acres Watershed Statistics Naturally Occurring Waterways: 880.36 miles Percentage of Free Flowing River Miles: 98 % Percentage of River Miles in Protected Lands: 1 % Protected Lands: 1 % Number of Dams: 3 Number of Selected Watershed Projects: 1 Number of Stream Crossings: 752 Near-Stream Roads: 475.65 miles Average Precipitation per Year: 34.89 inches Percentage Area above 15% Slope: 46.65 % Number of CalWater Units: 71 WBS TMDL Rivers 0 Number of Special Status Species: 11 Number of Holland Communities: 44

http://endeavor.des.ucdavis.edu/newcara/precipitation.asp?cara_id=7

Precipitation by Weighted Average Average Rainfall Amount per Isohyetal Unit Area Relative Contribution 14 inches 6624.54 acres 0.01 18 inches 103418.08 acres 0.19 22.5 inches 49249.18 acres 0.09 27.5 inches 81105.17 acres 0.15 35 inches 133182.2 acres 0.24 45 inches 75112.27 acres 0.14 55 inches 61869.76 acres 0.11 65 inches 27561.93 acres 0.05 75 inches 6103.25 acres 0.01

Average Precipitation per Year

Levels of precipitation play a huge role in many factors affecting watershed health. Precipitation levels affect water levels, temperatures and velocity. Reservoir levels, erosion levels and pollution runoff also fluctuate with the levels of rainfall. The following process was used to determine the average precipitation per year. The precipitation coverage represents lines of equal rainfall, isohyets, based on long-term mean annual precipitation data compiled from USGS, California Department of Water Resources, and California Division of Mines map and information sources. Source maps are based primarily on U.S. Weather Service data for approximately 800 precipitation stations throughout California collected over a sixty-year period (1900-1960). The minimum mapping unit is 1000+ acres and the isohyetal contour intervals are variable due to the degree of variation of annual precipitation with horizontal distance. The CARA database utilizes a weighted average to determine a single value of mean annual precipitation; the isohyetal areas, after intersection, are multiplied by the average rainfall for each isohyet-derived polygon and divided by the total area of the CARA watershed.

Lower Klamath:

http://endeavor.des.ucdavis.edu/newcara/basin.asp?cara_id=5

General Information Basin Name: Lower Klamath (CA & OR) Area: 979815.75 acres Watershed Statistics Naturally Occurring Waterways: 1780.41 miles Percentage of Free Flowing River Miles: 97 % Percentage of River Miles in Protected Lands: 15 % Protected Lands: 15 % Number of Dams: 0 Number of Selected Watershed Projects: 7 Number of Stream Crossings: 758 Near-Stream Roads: 409.83 miles Average Precipitation per Year: 79.62 inches Percentage Area above 15% Slope: 69.63 % Number of CalWater Units: 138 WBS TMDL Rivers 1 Number of Special Status Species: 15 Number of Holland Communities: 40

http://endeavor.des.ucdavis.edu/newcara/precipitation.asp?cara_id=5

Precipitation by Weighted Average Average Rainfall Amount per Isohyetal Unit Area Relative Contribution 45 inches 28991.77 acres 0.03 55 inches 166788.35 acres 0.17 65 inches 132569.76 acres 0.14 75 inches 172910.06 acres 0.18 85 inches 165031.8 acres 0.17 95 inches 151297.02 acres 0.15 105 inches 110815.55 acres 0.11 115 inches 51426.2 acres 0.05 125 inches 6.02 acres 0

Average Precipitation per Year

Levels of precipitation play a huge role in many factors affecting watershed health. Precipitation levels affect water levels, temperatures and velocity. Reservoir levels, erosion levels and pollution runoff also fluctuate with the levels of rainfall. The following process was used to determine the average precipitation per year. The precipitation coverage represents lines of equal rainfall, isohyets, based on long-term mean annual precipitation data compiled from USGS, California Department of Water Resources, and California Division of Mines map and information sources. Source maps are based primarily on U.S. Weather Service data for approximately 800 precipitation stations throughout California collected over a sixty-year period (1900-1960). The minimum mapping unit is 1000+ acres and the isohyetal contour intervals are variable due to the degree of variation of annual precipitation with horizontal distance. The CARA database utilizes a weighted average to determine a single value of mean annual precipitation; the isohyetal areas, after intersection, are multiplied by the average rainfall for each isohyet-derived polygon and divided by the total area of the CARA watershed.