These 2 studies attempted to predict people's intention to save water. Study 1 used a model based on Ajzen's (1991) theory of planned behavior (TPB) and other variables: vulnerability, 2 collective efficacy variables, and subjective effectiveness of alternative solutions (SEAS) to ease drought impact. Study 2 tested a model similar to that of Study 1, but with 2 personal efficacy variables added. Respondents in both studies were residents of Taiwan (Ns= 166 and 210). Analysis indicated that the modified models (R-2 >.32) were better than the TPB model (R-2 <.19), and SEAS and response efficacy had crucial effects on people's intentions to retrofit. The studies also found some significant but inconsistent effects of income, dwelling, and education.