WSP03031 - Laserfiche WebLink

Home Browse Search

to t'~ (."C'~ .,....; species, we ,estimate 40 use-days per wetland acre per season or a total of :":', 1. 7 million use-days during the breeding season within the Closed Basin project (:~ area. C. Bird Species of High Federal Interest Several bird species which are of high Federal interest seasonally migrate through the San Luis Valley utilizing the e~isting wetlands and wetland habitat. These species are included in tables 2, 3, and 4. Federally endangered species such as the bald eagle, peregrine falcon, and whooping crane utilize wetlands and wetland habitats as food or cover sources in the San Luis Valley. The long- billed curlew, great blue heron, greater sandhill crane, and Western grebe are bird species of high Federal interest which also utilize wetlands or wetland habitat in the area during migration. The maintenance of existing wetland areas in the San Luis Valley are important to the management of these bird species. II. Projects Impacts A. Wetlands Wetlands are lands that are transitional between terrestrial and aquatic systems. The water table is usually at or near the surface, or the land is covered by shallow water. For the purposes of the fish and wildlife wetland classification system (Cowardin et al. 1979), wetlands must have one or more of the following three attributes: (1) at least periodically, the land supports predominantly hydrophytes; (2) the substrate is predominantly undrained hydric soil; and (3) the substrate is nonsoil and is saturated with water or covered by shallow water at some time during the growing season of each year. To help determine the impacts of the Closed Basin Division, San Luis Valley Project on wetlands, the following information was reviewed: (a) Wetland inventory maps; (b) 1978-1980 shallowest and deepest water table maps; (c) U.S. Geological Survey (USGS) predictive water table drawdown maps; (d) BR infiltration test data for 1979-80; and (e) Numerous letters of correspondence and data transmittal between BR and FWS. The project could have several impacts on wetlands, some of which are quanti- fiable and others not. The more easily identified impacts are related to interruption of natural overland flow by the construction of the conveyance channel and direct effects of pumping. The channel is not expected to change local natural overland flows in Stage 1-2 of the project area since overland flows due to snowmelt runoff or irrigation returns are very rare there. Stage 1-2 area wetlands are generally replenished by direct precipitation. In Stages 3, 4, and 5, the affected area was taken to 8