46 



Fig.42. Prairie pothole wetlands continue to be drained for agriculture. 



Wetlands of Nebraska's Sandhills and 

 Rainwater Basin 



Wetlands within the Sandhills and Rainwater Basin of 

 south-central Nebraska are important to migrating sand- 

 hill cranes and waterfowl in the Central Flyway. About 

 2.5 million ducks and geese move through the Rainwater 

 Basin each spring. Ninety percent of the mid-continent's 

 white-fronted geese stage in wetlands of the Basin and 

 central Platte each spring. Pheasants also depend on wet- 

 land vegetation for nesting and brood habitat (Farrar 

 1982). Eighty percent of the continent's population of 

 sandhill cranes depend on wetlands along 70 miles of the 

 Platte and North Platte Rivers as staging areas during 

 spring migrations (Figure 43). Whooping cranes, an en- 

 dangered species, also roost in broad reaches of the Platte 

 River's channels (U.S. Fish and Wildlife Service 1981). 



The Nebraska Sandhills Region is the largest sand dune 

 formation in the western hemisphere covering approxi- 

 mately 20,000 square miles. Formed primarily by wind 

 action, the Sandhills consist of stabilized sand dunes, 

 exposed groundwater lakes in the valleys, and perched 



mineralized lakes on poorly drained soils. The grassland 

 economy of the Sandhills is primarily one of cattle graz- 

 ing. Large acreages of subirrigated meadows with water 

 tables close to the surface offer great potential for in- 

 creased grazing and hay production through development 

 of level ditching. Wetland destruction in the Sandhills has 

 accounted for over 28.000 acres or 15% of the original 

 wetlands (Nebraska Game and Parks Commission 1972). 

 Wetland loss has resulted from drainage, tilling for pivot 

 irrigation, and reduced groundwater levels from deep 

 well irrigation. 



Decreases in riverflows of the Platte River by upstream 

 diversions for consumptive uses in Colorado. Wyoming 

 and western Nebraska have reduced channel width by 80- 

 90% in many areas. This condition has promoted growth 

 of woody vegetation on former channel bars and islands. 

 Sandhill cranes prefer roosting in shallows and sandbars 

 where the channel is at least 500 feet wide and strongly 

 avoid narrower channels. Reduction in natural channel 

 width and increased growth of woody vegetation have 

 caused crowding at remaining roost sites. This situation 

 increases crane susceptibility to catastrophic losses due to 



