Basin-Wide Opportunities for Conjunctive Management in Nebraska

When river systems are connected to underlying aquifers, as in the case for most of Nebraska, surface water and groundwater must be managed together. Groundwater moves slowly and aquifers are hydrologically connected between stream and river basins. Surface water moves quickly and flows are highly variable, but is limited to channels and canals.  Conjunctive management is difficult due to the nature of these two types of flow. Groundwater withdrawals affect baseflow to the streams and irrigation canal seepage; deep percolation from field irrigation affects recharge to the aquifers. Therefore policy measures to augment recharge or increase irrigation efficiency have significant impacts on the basin-wide water balance. To further this discussion, we explore various conjunctive water management techniques being used in Nebraska. Using various conceptual models of a basin water budget hope to illustrate the trade-offs within the basin water balance and evaluate policy opportunities.