RUNOFF Determine the average annual runoff (m') from all streams flowing into Mono Lake. 1. Three large streams flow into Mono Lake, all from the Sierra Nevada (Fig. 1.2). These streams are gaged by the Los Angeles Department of Water and Power (DWP), and have the following average annual runoff. Lee Vining Creek 87.3 cfs (cubic feet per second) Rush Creek 44.8 ofs Mill Creek 37.0 cfs What is the combined average annual runoff of these three streams, in m'? 2. The Los Angeles DWP has been diverting water from Lee Vining, Rush, and Mill Creeks (below the gaging stations) for many years, running the diverted water through the Owens Valley aqueduct to Los Angeles. These diversions average 105, 305 acre-ft per year. Taking into account these diversions, what is the average annual flow into Mono Lake from these three streams, in m ? 3. Two small streams, not gaged, were measured with simple weirs to determine their runoff. The smallest stream, Andy Thompson Creek, was Triangular-natch Weir (90 ) measured with a 90 triangular-notch weir. This type of weir is most useful for discharges of less than I ofs. The formula for a weir with this geometry is Q = 2.54 15/2 where O is in cfs and h is in ft. Q M 2.54has The measurement, taken after flow is stabilized. Oin cls showed the water surface 6.9 inches above the notch. h in it Determine runoff (m'/yr)