Management for conjunctive use means more data needed to represent complexity of resource, researchers says. Goeke opened the 1994 Nebraska Water Conference with a presentation highlighting variables that complicate integrated management of Nebraska's surface water and groundwater resources, or conjunctive use. The annual Nebraska Water Conference was held March 14-16 in Lincoln. The difficulty is identifying what changes affect what area in what way. Basic variables affecting integrated surface-water and groundwater management are climate, topography, soils, the unsaturated zone and the saturated zone, Goeke said.
Rain provides overland runoff, filling streams.
It also replenishes groundater. Adequate precipitation also serves to diminish irrigation needs within a given period, so less groundwater is pumped and surface water diverted for that purpose. More than 77,000 irrigation wells are registered in Nebraska, causing a significant impact on groundwater levels in some areas. Subsurface geology, soil types and topography also influence surface-water and groundwater flow patterns. Most groundwater moves very slowly but some can move at much higher rates.