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MAINSTEM IRRIGATION WELL PUMPING Year Amount in Acre-Feet 1997 75,569 1998 46,965 1999 42,363 2000 65,295 2001 72,465 2002 63,453 2003 12,755 2004 11,762 2005 39,277 2006 24,730 The values for 1997 through 2006 were compiled by the Division Engineer from power and flow meter records. For this period, the irrigation pumpage in the mainstem averaged 45,463 acre-feet annually and ranged from 11,762 acre-feet in 2004 to 75,569 acre-feet in 1997. For planning purposes, mainstem pumpage should average about 46,192 acre-feet annually and should total about 28,246 acre-feet in a dry year. Bedrock Actuifer Wells. LAWMA's plan for augmentation covers 41 bedrock aquifer wells that are used for commercial, irrigation and municipal purposes. The pumpage from these bedrock aquifer wells totaled 303 acre-feet in 2006, representing 7 acre-feet of potential depletions. Gravel Pits and Wildlife Ponds and Sprin�. LAWMA's plan for augmentation covers 8 gravel pits, 3 wildlife ponds and 1 spring. The depletions from these structures amounted to 380 acre-feet in 2006. Stream Deuletions. The depletions for each river segment described above were estimated using the accounting model and the above-described pumping levels. The depletions are reduced to allow for (1) wells operating as alternate points of diversion for senior surface water rights, (2) pre-compact wells, and (3) usability factors applied to depletions at the State line from pre-1986 wells. The replacement requirements for an average year, such as 1950, totaled 20,841 acre-feet as shown on page 1, column 6 of Table 1 and were based on a series of full allocations of replacement water to the structures augmented by LAWMA such that the depletions approached steady-state conditions. The replacement requirements for the second dry year following a series of average years, such as 2004, totaled 9,149 acre-feet as also shown on page 1, column 6 ofTable 1. 4