This paper analyzes the demand for water in case of a multiple-part tariff in Denton, Texas. The model used is developed from Billing & Agthe's model by using the following variables: marginal price, difference variable, tax assessed value, lot size, house size, temperature and rainfall.. The results indicate that temperature has the greatest effect on water demand, since this area is considered to be a very warm area. Also, marginal price seems to have a strong effect on water consumption indicating that customer is well-informed to a change in rate schedule. This test supports the original idea of the previous articles that the coefficient on difference variable and that on income should have the opposite sign. However, this test can not prove that those coefficients should be equal in magnitude, since the proxy of the income variable can not represent the individual monthly income. In addition, this article introduces another variable which can be a proxy of outdoor water use. That is lot size showing the effect on water demand. The last variable used in the model, house size,does not have much effect on water demand and is dropped out in the final model.