2008-02-22_APPLICATION CORRESPONDENCE - C2008086 (42)

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Irrigation water has created wildlife habitat which differs considerably from those occurring naturally (BOR 1985). Conclusion This report presents information demonstrating the project area was not likely to have wetland characteristics prior to introduction of irrigation water. Most wetlands in the project area are the direct result of irrigation and are believed to be non jurisdictional. A wetland established and maintained solely by artificial irrigation does not meet the definition of adjacent wetlands to WOUS under the criteria contained in the 1987 COE Wetlands Jurisdictional Manual or its regional supplements. Irrigation waters are generally considered non jurisdictional by COE (RBM 2007-02). The hydrologic source associated with these wetlands should not be considered a tributary because it is water allocated from the TNW, Colorado River, to the Grand Valley Canal for the sole purpose of irrigation. No jurisdictional WOUS are collected from tributaries in the Mack lateral and water in excess of that required for agricultural purposes is conveyed back to the Colorado River as irrigation return flow. There is no information available to show that these irrigation ditches: 1) are or could be used by interstate or foreign travelers for recreational or other purposes, 2) produce fish or shellfish which are or could be taken and sold in interstate or foreign commerce, or 3) are or could be used for industrial purposes by industries in the interstate commerce (33 CFR 328.3). Consensus of local experts and studies is that the areas with wetland characteristics are a direct result of irrigation. If the source of irrigation water was removed the area would revert to uplands and wetland characteristics would no longer be apparent. Fringe wetlands and adjacent flood plains are the only naturally occurring wetlands in the area. WestWater Engineering Page 10 of 75 January 2008 DBMS 431