This research aims to develop a mathematical model linking the available water resources and the demand of population and agricultural and industrial on these resources, where they were to rely on time series from 2000 until 2011 and study and know their direction and growth, and it was the most important results: 1- increasing the size of the demand (population, agricultural and industrial ) on water resources during the period (2000-2011), where he found a positive relationship between the size of a very strong demand on water resources and time. 2 - increasing the volume of surface water resources and groundwater available during the period (2000-2011), where he found a positive relationship and a very solid between the size of surface water and groundwater resources and time available. 3 - there is an excess of total available water resources and the total volume of demand. 4 - there is a statistically significant relationship between the total volume of available water resources, and demand (population, agricultural and industrial) on them, where we can and relying on multiple regression equation to predict the total volume of water resources through the volume of demand ( population, agricultural, industrial) on them.