first i was given a random city to design a water supply for. as my group did we first estimating the population of the city for 2035 by using two methods : 1) Arithmetic (linear) growth 2) curilinear method of the growth (graphic). then we got our estimated population in that year and then by knowing the population we estimated the water variability and final design water demand. by knowing these values we came up with the required capacity of an elevated storage tank.second using the population we estimated we designed water distribution system. then we used hardy cross method to analysis procedure to size the distribution system. then by the information we had we determine the pressure head necessary on the pump and the height of the elevated storage tank.