Praise be to God, and prayers and peace be upon the Messenger of God, may God bless him and grant him peace. Then ... This research has adopted two methods in dealing with water consumption: an indication of how water is consumed, and the optimal method of consumption . The problem of the research lies in the declining levels of water at the local, regional and international levels . And the problem of groundwater pollution, and the problem of building the Renaissance Dam in Ethiopia at the local level . The research reached several results and recommendations, the most important of which are: that rationalizing water consumption is a Sunnah and an act of worship that the slave will be rewarded for, including: the permissibility of using water other than pure fluids to remove impurity; Rationalization, including: the multiplicity of types of water, which indicates that it is not monopolized by tap water only, but the water of the sky, rivers, wells, seas, etc. is included in pure water, including: it is disliked to prolong the toilet unnecessarily, including: it is permissible to leave the body massage in case of need Water, including: the permissibility of tayammum at the time of great need for water, or the water was not sufficient, including: rationalization in the water required for ascites, including: the permissibility of treating sewage water and using it in purifications and others, if it is proven not to harm, including: permissibility of purification by steam, including: Permissibility of solar purification of water and water, including: the prohibition of selling surplus water, including: showing the veneration of the value of the Nile River in the Sunnah of the Noble Prophet , including: sending a message of reassurance to everyone who lives on the banks of the Nile River that what is done is God and by His command , and that its source From His Heaven - Blessed and Exalted be He -. Among the most important recommendations: Do the necessary research to benefit from rainwater, especially the rainiest areas, including: Educating people on jurisprudential issues using various modern means of communication . key words : Consumption. Purity. ablution .washing. tayammum