Iberdrola Renewables has proposed a wind-energy facility in Brookings and Deuel Counties, South Dakota, near the towns of White and Astoria. Western Ecosystems Technology, Inc. (WEST) conducted baseline surveys and monitored wildlife resources in the Buffalo Ridge II Wind Resource Area (BRIIWRA) to estimate the impacts of wind-energy facility construction and operations on wildlife. The principal objectives of this wildlife monitoring study were to: 1) estimate the seasonal, spatial, and temporal use of the survey area by birds, particularly raptors, defined here as kites, accipiters, buteos, harriers, eagles, falcons, and owls; 2) identify the species and estimate the density of nesting raptors in the study area; 3) estimate the seasonal and spatial use of the study area by bats; 4) describe incidental observations; 5) estimate any potential impacts to birds and bats that could result from construction and operation of the proposed wind-energy facility; and 6) identify potential project modifications and/or mitigation measures that could reduce negative impacts. This report provides results of the baseline surveys at the BRIIWRA conducted from March 12, 2008 through November 5, 2008. Baseline surveys conducted at the BRIIWRA in 2008 included fixed-point bird use surveys, raptor nest surveys, acoustic bat surveys, and incidental wildlife observations.
The BRIIWRA, currently about 49,463 acres (20,017 hectares; ha), is located in northeast Brookings County and southern Deuel County in eastern South Dakota along the South Dakota/Minnesota border. The original project boundary covered a smaller area in Brookings County only; the current project boundary was adopted after the surveys were initiated. Topography in the current project area is flat to rolling. Approximately 60% of the WRA is composed of tilled agriculture. The next most common landcover is pasture, which comprises 20% of the BRIIWRA. The Buffalo Ridge Wind Project will have a nameplate capacity of up to 306 Megawatts (MW). Iberdrola has not selected the turbine model and size yet, but is considering turbines that range in size from 1.5 to 2.4 MW. The project will consist of up to 204 1.5-MW, 153 2.0-MW, 145 2.1-MW, or 127 2.4-MW wind turbines.
Fixed-point surveys (variable circular plots) were conducted approximately once every other week. Birds seen during each 20-minute (min) fixed-point survey were recorded. Nineteen points were selected to achieve optimal coverage of the study area and habitats within the study area. The project as initially described was limited to Brookings County and this area contained 15 points. In fall 2008, notice was given that the project area was expanding into Deuel County and an additional four points were added in this area. Each survey plot was a 2,625-ft (800-m) radius circle centered on the point for large birds and 328-ft (100-m) radius for small birds.