REP17589 - Laserfiche WebLink

Home Browse Search

-8- D Federal Regulation All wetland acreage delineated on the Appendix 1 map falls within the federal register definition and therefore would be regulated by Corps authority. Clearly, a fraction of this acreage is influenced by irrigation, however all wetland areas do occur, and likely historically occurred (pre-irrigation), in natural low areas or drainage swalea. Those wetlands that do not fall within Corps jurisdiction are located along and within irrigation ditches. Irrigated wetlands are not indicated on the wetland map. Clearly, the mature cottonwood trees that create a fringe on both aides of the ditch are dependent upon ditch flow. However, these trees do comprise excellent wetland type habitat for wildlife; it has been reported that they "probably support the richest wildlife communities of any local habitat" on the Dowe Flats site (Thompson 1987). E. Recommendations Development: In meeting with Corps of Engineers representative Terry McKee, it was determined that dam construction can possibly take place without directly impacting wetlands or other waters of the U.S. While this eliminates the need for a 404 permit and subsequent mitigation, the project proponent may want to consider offsetting impacts by replacing wetlands that may be inundated by the proposed reservoir. The number of wetland acres impacted is dependent upon the selected reservoir scenario (Table 1). Subsequent steps to offset the effects of wetland inundation follow. 11 A draft mitigation plan should be compiled. 2) In this project the amount of wetland to be created would be up to the developer's discretion, although a one to one ratio would be optimum in terms of environmental compensation. Wetland creation from dryland and/or enhancement of existing wetland are the most common forms of mitigation. mitigation and construction can cost anywhere from 1500 to 530,000 per acre. AWC can work closely with the developer to prepare an adequate, cost-efficient mitigation plan using creation and/or enhancement techniques both on- and off-site. If dam construction directly impacts wetland or waters of the U.S., a 404 permit will be required. A 404 action will trigger regulation of wetland indirectly impacted by inundation. If total direct and indirect impact is greater than 10 acres, an individual permit will be required. Permit processing averages 60 days and mitigation is expected. If impact ranges from 1 to 10 acres, a nationwide 26 permit is processed. Processing averages 14 to 21 days and does not necessarily require a mitigation committment. Habitat Bnhancement and/or Mitigation: Habitat enhancement can be implemented to restore natural wetland functions and to provide for increased wildlife habitat. The sites of greatest enhancement andJor mitigation potential occur along intermittent