Determing boundary condition in MODFLOW Posted February 22, 2018 · Report reply Hey all! I have a question regarding boundary condition set up. I am working on a regional model of an large aquifer field which is used for drinking water purposes. Hydrologic and hydrogeologic conditions are at this stage of the research verry clear. We are dealing with open aquifer field where boundary condition is representing inflow to the aquifer from surrounding sedimentary formations. We have calculated the infow using National groundwater recharge model and at this stage we have data of infow (Q [m^3/s]) for every cell of the boundary condition. Is it possible to calculate the needed hydraulic head in order to simulate the boundary conditions as constant head?