The study was conducted with the objectives of developing residential water use models for Ponce and San Juan, Puerto Rico, and comparing these models with a previously developed model for Mayaguez, Puerto Rico. The results of this study have shown the feasibility of estimating water use in private residential developments based on property value as the basic characteristic. The rationale employed was that assessed value of property serves well as an indirect practical indicator of the effect on water use of such socioeconomic factors as number and kind of home water-using fixtures, lawn and garden areas, automobile washing requirements, education, habits, occupation and effective family buying income. Significant differences were observed in comparing private urbanization models for Ponce and Mayaguez and San Juan and Mayaguez respectively. It is therefore recommended that separate models be employed for estimation purposes in these cities.