WSP03823 - Laserfiche WebLink

Home Browse Search

I I 0685 I I I I I I I I I I I I I I I I I water by the Catlin canal Company and the delivery of state water to special state headgates located along the canal. Therefore, the historic pattern of return flow from canal losses would not be altered. This plan insures that proper amounts of water corre- sponding to the second type of return flow would be left in the Arkansas River system by limiting the average annual storable water (column 4 plus column 6 in Table 7) to the historic consumptive use (Table 6). The critical return flow location is the Rocky Ford headgate to protect the Fort Lyon-Holbrook exchange. In this exchange, the Holbrook Mutual Irrigation company re- leases water into the Arkansas River for diversion by the Fort Lyon Canal company in return for direct diversion at the Holbrook headgate. The critical parameter is the adequacy of the river flow to satisfy the Rocky Ford decree. During historic conditions shown in Table 7, which was pre- pared after interviews with Catlin officials and inspection of USGS topographic maps, only the irrigation of 77 acres with 129.08 shares of Catlin stock through laterals 6 and 17 could have produced return flows above the Rocky Ford headgate. These circumstances combined to produce 17 per- cent of the total return flow resulting from the historic use of the State-owned Catlin stock. To protect this exchange, water would be made available upstream of the Rocky Ford headgate by utilizing either the Catlin wastegate as a State headgate or a separate State headgate and setting the gate for the number of shares required to deliver the proper amount of water. The USGS assisted in the evaluation of return flow timing patterns. Techniques5 used to calculate stream depletion caused by well pumping were applied in reverse using re- charge instead of groundwater withdrawals. The recharge amounts were average monthly deep percolation calculated in Appendix C since these actually are the amounts that were returned historically. The applications were made by repeating them over a lOO-year period. This time -24-