In this study, we analyze water availability for allocation of water rights in Nuble River Basin, Chile. The methods include evaluation of the natural regime, determination of current water demand, and calculat ion of a water budget. Water availability was calculated using TRMM and instrumental records from rainfall and discharge gauges. Water demand was computed from a new inventory of water rights records developed for this study. Results reveal a hydrological deficit. More specifically, May and October showed the highest deficit, with 7.8 m(3)/s for permanent water rights and 63.7 m(3)/s for sporadic water rights. In order to reduce this deficit the method to allocate water right shoul d include better estimations of hydrological balances by incorporating updated and validated water rights records and more hydrometeorological instrumentation in mountain watersheds. Furthermore, we assert that the government must play a bigger role in efficient water management, considering the present scenario of more frequent droughts.