Scope of the Challenge
“Channel widths along the river, have reduced by as much as 80 to 90 percent of the former 1860’s channel in the upstream reaches, with lesser amounts of decrease in the reaches near Grand Island.” (pg. S-28)
“Of the historic river channel area (high bank to high bank), roughly half of this area had become vegetated by 1938. From Lexington to Grand Island, Nebraska, about 27,000 acres of unvegetated channel remained….The EIS Team’s analysis similarly indicates that from 1938 to 1998 the unvegetated portion of the channel between Lexington and Grand Island had been reduced to roughly 9,500 acres, an additional 65 percent loss.” (pg. S-30)
“…a sediment imbalance is created in the Central Platte River and erosion of the bed and banks of the channel begin directly at the discharge of the Johnson-2 Return…This creates erosion and degradation of the river bed in the upper part of the Central Platte Habitat Area.” (pg. S-29)
“wetlands and wetland meadows have been significantly reduced in the last 100 years….It is estimated that native grassland and wet meadow acreage in the Central Platte River has declined 73 percent since the beginning of development.” (pg. S-31)
The Species at Risk
Whooping crane: “In 1941, the migratory population numbered 16 individuals, including 6 to 8 breeding birds. As of March, 2000, 188 whooping cranes were recorded in the wild flock that migrates through the Great Plains and across the affected area of the Platte River Basin. In March, 2002, the population had dropped to 173 birds, but it rebounded to 215 birds by February, 2005.” (pg. S-31)
Piping plover: “Statewide in Nebraska, interior least terns and piping plovers are undergoing a significant population decline. During the 2001 international census, 213 piping plovers were counted along the North Platte, South Platte, Platte, Loup, North Loup, and Elkhorn Rivers in Nebraska. Another 87 piping plovers were counted along the Niobrara River, resulting in a total of 300 birds counted in Nebraska. This represents a decrease of 18 and 25 percent from the 1996 and 1991 census totals, respectively.” (pg. S-32)
Interior least tern: “Population analysis indicates population trends are generally positive in most of the interior least tern’s range. However, population trends are generally negative for the Platte River.” (pg. S-32).
Pallid Sturgeon: “Of 42 occurrences of pallid sturgeon reported in the lower Missouri River Basin in Nebraska from 1980 through 2001, 20 are from the Platte River, Elkhorn River, or the Missouri River near the Platte River confluence. Thus, 48 percent of the observations in Nebraska are from an area representing about 10 percent of the range.” (pg. 33)
Impacts of the Proposed Program on Agriculture and the Economy
There are 10.9 million acres of irrigated cropland in the Platte River basin in Colorado (2.7m), Nebraska (7.0m) and Wyoming (1.2m) (Vol. I, pg. 5-255)
“The 10,000 acres of the Program’s First Increment represents 2.3 percent of the entire Central Platte Habitat Area, which consists of about 434,199 acres.” (Vol I, pg, 5-277).
“Compared with the Present Condition, the action alternatives would not significantly affect population and demographic trends, health risk factors, flooding, land use, or income and employment.” (Vol I, pg 5-273).
“The impacts (positive and negative) represent less than one-tenth of 1 percent of the total economic activity in the region….Impacts of this magnitude would be very difficult to detect.” (Vol. I, pg. 5-279)
“Most of the alternatives increase overall power generation and economic value of power produced, due to the increased volume of waters being moved through the powerplants each year.” (pg. S-85)
Impacts on Other Resources
“The alternatives result in more drawdowns below both reservoir volumes identified by the Wyoming Game & Fish Department (WG&F) as providing good conditions for fisheries, and also a small number of additional drawdowns below elevations identified as critical to the fishery at Seminoe and Pathfinder reservoirs….Wyoming Water Development Commission has entered into an agreement to contribute up to $2 million to the Department of Game & Fish during the First Program increment to support the restoration of fisheries in the main North Platte Reservoirs and river reaches should they be significantly adversely affected by the Program.” (pg. S-83).
“The Program actions to improve river flows through the Central Platte Habitat Area affect the operations and reservoir levels for Lake McConaughy in ways that may affect the fisheries in Lake McConaughy and Lake Ogallala….Walleye recruitment is expected to be reduced….reduce the frequency under which the optimum smallmouth bass spawning habitat is accessible and reduce the total amount of spawning habitat available in a given year substantially.…it is more likely that temperatures which support the Lake Ogallala trout fishery may be negatively affected.” (pg. S-84).
“Some of the higher-elevation boat ramps (at Lake McConaughy) will become functionally unusable under most conditions, while some of the lower elevation boat ramps will see relatively few effects.” (pg. S-86).