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The observation wells can be subdi�ided into two types: those which lie within or very near the <br />South P�atte River floodplain, and those located in tributary valleys. The number of observatian <br />wells in tributary �alleys exceeds the number along the South Platte floodplain by 21. <br />An evaluation of the data of beginning water le�els as compared to Spring 2001 levels reveats <br />that approximately 58.2% of the wefls ha�e experienced a water level decline which compares to <br />a 37.7% decline in the 200D report. By comparison, 1 Q.1 % of the wells experienced a rise in the <br />Spring 2QQ1 as compared tv the Spring 1988 water le�el. This percentage is less than the 2�D0 <br />report �alue �15.9%). Declines o� Spring 1988 to Spring 20�1 range from - 0.�8' to - 8.D5 as <br />compared to the range of - 0.36' to -11.6a' in the 2��0 report. Declines on the order of 0.01' are <br />insignificant in that such changes can be caused by wind, earth mo�ement, and the effect of <br />e�apotranspiration and phreatic consumption or maybe errors in data recording. The table <br />falowing this narrative entitled "Table of Water Le�el Trends of the 5outh Platte Allu�ium through <br />5pring 20�1" recaps the statistics to date for this ongoing report in terms of all wells within the <br />tributary valleys and the South Platte main stem/floodplain. <br />These data also reveal that the averages of the water le�el changes from Spring 1988 to Spring <br />2�41 wells within the tributary valleys {both rises and declines} are more than the averages of the <br />South Platte floodplain alfu�ium. By comparison, in 2�00-2QQ1 the average rise and declines af <br />Spring 1988 �s. Spring 20�1 changes in the tributary �alleys were for the second year running <br />less than those in #he South Platte floodplain. <br />The a�erage annual wa#er le�e! change for the period of record for this report is averaging - 0.12 <br />ftlyr in the South Platte floodplains and - O.D4 ft/yr in the trEbutary valleys. The tributary valleys <br />experienced less annual rise overail in 2�01 than in 2000. Concurrently, the annuaf rise of the <br />South Platte floodplain was greate� in 2001 than 20�0 Annual declines in the tributary valleys and <br />the South P�atte floodplain were mostly less in 2001 than 200�. <br />_2_ <br />