The GGU-DRAWDOWN program allows the calculation of multiple well installations. Building pits with rectangular and any other outline shape can be calculated. The influence of open water and sheeting walls can be taken into consideration. The program has optimisation routines for well number, well radius and well depth. After input of the building pit dimensions you can change to the optimisation routines to get, in seconds, an optimally configured ground water management. Graphic analysis (draw down sections, system sections, isographs in colour and "normal”, as well as several legends) allows you to present all calculation results as a data protocol on the screen.