Is There Enough Water? Implications for Understanding Fish-Habitat Linkages in the Great Plains

The Niobrara River is a primarily groundwater-fed river flowing through the Nebraska Sandhills.  The river is economically important for potentially conflicting purposes (e.g., recreation versus irrigation).  There have been some flow management and consumptive demands implemented within the basin, but the Niobrara still retains relatively natural hydrologic connectivity and currently maintains a unique fish community.  Recent policy decisions have established that a portion of the Niobrara River is ‘fully appropriated’ meaning that no new efforts can be pursued to withdraw water from the river; whereas, water withdrawals are still allowed in some areas.  The result has been a growing concern over future water allocations in areas that are still open to water development.  Therefore, we initiated a study to quantitatively assess instream aquatic habitat availability over a range of flows for key species and guilds to determine the extent of the effects of future water withdrawals on native fishes.  The implications of these results on current and future management of the river to meet anthropogenic needs and those of other biota will be discussed.