Sludges generated during purification of water for human consumption are produced in large volumes and have high environmental polluting potential. The sludge dewatering technique using geotextile closed systems has been used to reduce the sludge volume for final disposal. It is a system that allows encapsulation, insulation, dewatering and disposal of sludge, which allows control of the input and output variables of the system. Also known as geotextile tubes, geotextile containers and geotextile bags are a function of their size. This work presents a discussion about the main factors influencing this sludge dewatering technique and its applicability for sludges generated in a water treatment plant. The study includes tests with single filling and with refilling the small geotextile bags in equipment constructed to simulate control of operational conditions, such as flow rate and pumping pressure. The evaluated performance of this system according to parameters proposed in the literature is also presented. The results obtained indicate that the efficiency of the dewatering technique depends on both the characteristics of the sludge and the geotextile properties. This study indicates the importance and efficiency of the dewatering technique in geotextile closed systems in reducing the sludge volume for final disposal.