The average monthly discharge (1964-1988) is 0.133 cubic meters per second (~4.7 cubic feet per second) as it enters the reservoir at 1646 m (5400 ft) elevation (U.S. Geological Survey records). The pattern of stream flow exhibits a straightforward annual pattern, characteristic of this geographic region -- high spring flows driven by snow melt followed by very much reduced flows derived from groundwater throughout the remainder of the year. Spring melt flow, which is typically an order of magnitude greater than other periods of the year, peaks in May and persists for 6-8 weeks. The average monthly stream flow rate during May is 0.416 cubic meters per second (14.7 cubic feet per second). By September, the lowest average monthly flow rate, stream discharge has decreased to 0.058 cubic meters per second (2.0 cubic feet per second). Mean stream flow rates do not increase during the summer months, although nearly one fourth of the annual precipitation falls during this period.
