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<br />II <br />. <br />.. <br />II <br />III' <br />III <br />III <br />II <br />III <br />II <br />.. <br />II <br />II <br />II <br />.. <br />III <br />II <br />II <br />- <br /> <br />'~ <br /> <br />Eighty years of Bear Creek stream flow history are attached in Appendix E. This data was <br />graphed in Appendix F to show the running average flow on Bear Creek, and the annual highs <br />and lows that have occurred over that period, An analysis of the historic annual flow in Bear <br />Creek, and it's variations found that dry year monthly flow fluctuations do occur to a degree that <br />would constitute a drought on a regular basis, At first look however, the Bear Creek Watershed <br />appears to provide an abundant amount of water with a nonnal stream flow average of almost <br />38,000-acre feet of water per year, A closer look though reveals that 63% of the years had below <br />average stream flows, In 22 % of the annual stream flow records, the flow was below 20,000- <br />acre feet per year or almost half of the annual average, Further three consecutive years of below <br />average flows occur on a regular basis, Three consecutive years of low flow incidents occurred <br />in the 90's, the 70's, the 60's, and the 50's, The 50's low flow event involved four consecutive <br />years, and resulted in the most dramatic of the drought cycles that occurred on Bear Creek, In <br />the final analysis, it is quite apparent that drought periods and high water periods are a regular <br />occurrence on Bear Creek, making planning for drought responses even more criticaL <br /> <br />The attached chart in Appendix G shows the peak water use demand for the water system at <br />buildout, and present conditions, which can be compared with the low flow months on the Bear <br />Creek history chart to determine the actual risk exposure for a possible drought. <br /> <br />The drought responses in this plan are based on the current number of taps on the water system, <br />which is 5350 equivalent taps, serving a population of approximately 14,000, The plan will have <br />to be modified in the future to respond at higher stream flow conditions at the water system <br />buildout of 6500 equivalent water taps, At the current tap level the months that drought <br />conditions would have caused the District to respond at the various drought response levels are <br />listed in the following table, <br /> <br />Frequency of Drought Response Based on Bear Creek Gauge History <br />Response Levell Response Level 2 Response Level 3 Response Level 4 <br />vear / month / cfs vear / month / cfs vear / month / cfs vear / month / cfs <br /> 1934/ Oct! 9.5 <br />1939/ Sept! 12,6 <br />1950/ Oct / 12.5 <br />1954/ June /11.5 <br />1954/ Sept / 12,8 <br />1956/ Oct! 12.3 <br />1962/ Sept / 11.4 <br />1962/ Oct / 12,6 <br />1963/ May /12.4 1963/ July / 5,7 <br /> 1978/ Oct! 10,2 1978/ Aug / 6,6 <br /> 1978/ Sept! 5.4 <br /> <br />8 <br />