Quali-quantitative evidence on water quality by a governance process with payment for environmental services in a water supply watershed

Evidências quali-quantitativas da qualidade da água por um processo de governança com pagamento por serviços ambientais em uma bacia hidrográfica de abastecimento de água

ABSTRACT

For the efficient management of water and soil conservation, quality and quantity aspects must be integrated. However, there is still a lack of studies with this synergy including governance processes. The present research evaluated for ten years (2010-2019) quality and quantity aspects of a water supply source and the Payment for Environmental Services (PES) implementation to investigate public policy efficiency and its effect on water resources. We used statistical analyses for comparing means, graphical analyses (trends, time series, duration curve, standard deviation), and correlation and multivariate analysis to evaluate parameters’ behavior after the PES implementation. Results showed that there was a significant reduction in turbidity, COD, and total suspended solids. Furthermore, water flow rate, total nitrogen, total phosphorus, and dissolved oxygen remained stable after the implementation of conservation practices, as confirmed by the multivariate analysis. Water quality index (WQI) between “Good” and “Great” and chemical and hydrobiological parameters below the maximum allowed values reflected on the water quality maintenance. Participative decision-making based on dialogue between stakeholders and trust in PES were key elements for success.

Keywords:  Water and soil conservation; WQI; PCA; Cluster; Water policies