The main objective of the present study is to apply the nonlinear regression (NLR) model in order to forecast water demand in Adana city of Turkey. The average monthly water bill, total subscribership, atmospheric temperature, relative humidity, rainfall, global solar radiation, sunshine duration, wind speed and atmospheric pressure are selected as independent variables. Meteorological parameters were taken from Adana meteorological station, and the other parameters such as water consumption, total subscribership and water bill values were supplied from Adana Water and Sewerage Administration during the periods of 2000-2009. In order to get a successful simulation, first, all independent variables were added to the "enter" regression model. Then, the method of stepwise multiple regression was applied for the selection of the "best" regression equation (model). Thus, the best independent variables were selected for the NLR model. Consequently, while water consumption in Adana city is 3.84 million m(3) at the end of 2009, it will increase up to 4.99 million m(3) by the year 2020.