Evaluation of water resource preservation areas in the Hydrographical Basin of Andreas Stream, RS, Brazil, using environmental monitoring programs

Abstract

This research evaluated the effectiveness of the implementation of water resource preservation areas in the Hydrographical Basin of Andreas Stream, county of Vera Cruz, RS, Brazil, established through Payment for Environmental Services (PES), using an environmental monitoring program to assess physical, chemical and microbiological variables. The PES is linked to the "Water Guardian" project, which aims to ensure the preservation of water resources by paying farmers for providing the environmental services to protect the springs and riparian areas that lie within their properties. Twenty sampling stations were selected for collecting water samples monthly during the period July 2012 to June 2014 (460 samples) to evaluate the following variables: water temperature, pH, turbidity, dissolved oxygen, biochemical oxygen demand, nitrate, ammonia nitrogen, phosphate, total dissolved solids and thermotolerant coliforms. The evaluation was made based on decree 357/2005 of the National Environmental Council (CONAMA) and by applying the Water Quality Index (WQI). The results indicated a significant improvement in the water quality when comparisons were made between the periods before and after the installation of the preservation areas. The sampling points classified as “good” (CONAMA and WQI), which indicates water of good quality that is appropriate for multiple uses, increased from 52.0% to 72.0%. In this sense, promoting the preservation of headwaters and riparian zones becomes of fundamental importance and highlights the role of PES as an operational tool for water resource preservation.