Good morning or evening, i'm trying building a model with different layer (that I create from boreholes-> tin-> solid -> conceptual model), and under -40 meter from the surfaces i have an aquifer, Above and below the acquifer i have differt layer with different material. In any case i create in MAP DATA: 1 coverage, with 2 no flux arcs, and 2 arcs defined as specific head ( i use the flow line of the piezometry for them), and some well. 1 coverage, with the poligon of source and sinks( rain and EV) i create a modflow model, but i read different tutorial, and if i use as starting head the top elevation modflow give as reply only dry cell, but if i put as starting head the value of the piezometry, modflow don't work. someone have some suggestion or idea? thanks in advance for all the reply sckara ps. i'm using a modflow model 2005, package LPF, Solver PCG2