Costos mínimos de compensación y cuantificación de la oferta hídrica en la cuenca alta del río Sauce Grande, Argentina

The aim of this work was to estimate the monetary cost of increasing water supply due to a change in current land use, in order to establish the minimum compensation costs for a future System of Payments for Environmental Services in the Upper Watershed of the Sauce Grande River. The work involved three steps: simulation of the infiltration for different rainfalls applying the hydrologic model hec-hms, calculation of the cost of changing the productive systems and estimation of the cost of increasing water supply. Results consisted of the thematic maps needed for simulations and the tables that showed variation between rainfalls with different recurrence intervals and different land use. For the recurrence of 1:1 the cost of opportunity was U$S 1.2 l.m-3, for the recurrence of 1:3 was U$S 0.73.m-3 and the lowest cost found was of U$S 0.62. m-3. We concluded that these costs will support future planning on the use of water resource within a system of Payments for Environmental Services, but it is also important to considerate that a contingent valuation is needed in order to establish the people's will to pay for the use of this resource in the watershed.