Interaction of streams and ground water in selected tributaries of the Republican River, Nebraska, 1998-99

BACKGROUNDThe Rep ubli can Ri ver Bas in occupi e. pan of northeast Colorado.north we t and north-central K an a .and outhwe t bra ka.The Republican Ri ver and th e ground wa ter in the underl y ing sa nd and gravel depos it.occupying the river valley (a llu vial aquifer) arc important ources of wa ter.Irri gati on is common in many areas of the Repub lican Ri ver B as in , using urfa e water from th e Republi ca n Ri cr or it.tri butarie , or ground wa ter from well s in the a oc iated allu vial aqui fers.In 1997 , th e .S. Geological Survey SGS) entered a 4-year co perative agreement w ith the Nebraska Republi can Ri ver M anagement Di stricts (L ower, Middle, pper, and Tri-Basin atural Resources Di stricts ( RDs) , th e Frenchman Valley, Hitchcock and Red Will ow, Frenchman -Ca mbridge, and ebra ka B o twick Irrigati n Di stri ct ), and th e outhwest ebraska Resource Conser va ti on and Development Area to develop a regional ground-water-now model (a mathemati ca ll y based computer 40 ' EXPLANATION program th at simulate ground -water fl ow) of the Rep ubli can Ri ver Bas in upstream of the USGS treamflow tat ion near H ardy, ebra ka (fig.I ) .