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<br />Table 3 Cont. <br /> <br />32 <br /> <br />Post-Project Conditions for the Animas-La Plata Project <br />at Farmington, New Mexico <br /> <br />WET <br /> <br />Water Year 1949 (units = cfsl <br /> <br />Section <br />Baseline <br />987 <br />939 <br />896 <br />864 <br />1149 <br />1155 <br />2647 <br />6474 <br />9977 <br />3750 <br />849 <br />617 <br /> <br />Month <br />October <br />November <br />'December <br />January <br />February <br />March <br />April <br />May <br />June <br />July <br />August <br />September <br /> <br />7 ALP <br />DeDletions <br />-141 <br />-82 <br />-49 <br />-49 <br />-59 <br />-115 <br />-348 <br />-120 <br />-277 <br />-514 <br />-291 <br />-42 <br /> <br />Post-Project <br />Conditions <br />846 <br />857 <br />847 <br />815 <br />1089 <br />1039 <br />2299 <br />6354 <br />9700 <br />3236 <br />558 <br />575 <br /> <br />Percent <br />Chance <br />-14 <br />-9 <br />-5 <br />-6 <br />-5 <br />-10 <br />-13 <br />-2 <br />-3 <br />-14 <br />-34 <br />-7 <br /> <br />The Project will cause discrete, identifiable, additive, adverse impacts to <br />the San Juan River endangered fishes. As shown in the flow analysis, the <br />Project will cause flow depletions which, in addition to existing projects, <br />will further alter historical flow regimes. <br /> <br />Since 1963, the operation of all existing projects, especially Navajo Dam, has <br />significantly altered flows of the San Juan River resulting in a decrease in <br />average spring peaks and a doubling of average winter base flows. The Project <br />would further reduce the remaining spring runoff within occupied habitat. The <br />flow analysis shows depletions of up to 61 percent in May of the <br />representative dry year. The fact that the Project would further deplete <br />flows during peak runoff is of concern to the Service because this period is <br />of great significance geomorphically and ecologically. This is the most <br />dynamic period in the cycle, and it precedes the very critical spawning period <br />of the endangered fishes. Observations clearly demonstrate that the spawning <br />activities of these fish are synchronized with and are undoubtedly influenced <br />by the spring runoff period (Archer et al. 1986, Archer and Tyus 1984, Tyus <br />and Karp 1989). The Service believes that peak spring flows are very <br />important for maintaining channel geomorphology, providing access to <br />off-channel habitats, stimulating spawning migrations, and preserving suitable <br />spawning substrates. <br /> <br />While the precise volume and duration of flows required for maintaining and/or <br />improving important physical and biological needs are unknown, it appears that <br />