Brazilian water management model is decentralized with full participation of many actors (Law 9433/1997). The main management tool is a charging system for water use. The first experience in charging for water use took place in the State of São Paulo: The Paraíba do Sul River Basin (2003) and the Piracicaba, Capivari and Jundiaí River Basins (RB-PCJ) in 2006. In addition to these, there are four basins with charging for water use: Sorocaba and Mid-Tiete, Region of littoral, Low Tiete and Upper Tiete.
Sao Paulo state has a critical availability of water resources. The metropolitan region of Sao Paulo has more than 20 million inhabitants. This population is distributed in a 8051 km² area, about 0.1% of the national territory. However, this population is concentrated in an area of 2209 km². This means that 10% of the Brazilian people are concentrated in a smaller area to 0.1% of the territory.
This paper aims to discuss the relation between the charging for water use and water security in river basins, and analyze how the funds have been used. Therefore, the study area was São Paulo state in Brazil.
The methodology is divided into two parts. First, a literature review on the issue of water security will be held, seeking to outline the impacts on water availability in the state. Second, a qualitative and quantitative analysis of water management indicators will be developed, based on the São Paulo State Water Resources Public Policy. There are 45 indicators, divided into three groups: socio-economic and cultural scenario (group 1), the general situation of water resources in São Paulo (group 2), and implementation of the Basin Plan (group 3). These include variables such as the rational use of water resources; investments programs aimed at protecting the quality and quantity of water resources; conservation and protection of water resources include the recovery of water resources, payment for environmental services and restoration of riparian forests.
Results and discussion
Our initial results show that in the first years of charging in the Piracicaba, Capivari and Jundiaí basins, the sanitation sector accounted for the largest portion of the payment (84%), industry, 13%, and agriculture, 3%. There were 165 works and projects executed in the RB-PCJ, of which 68% was allocated to basic infrastructure; 28% combat losses; 4% for environmental education, prevention and protection against extreme events, etc.
The results show that the vulnerability of water resources in São Paulo state was related to the degradation of areas occupied by native forest. Apart from that, coexisting problems of susceptibility to flooding, groundwater drawdown risk, improper disposal of solid waste, demand for higher water availability or near the critical level, among others, also contributed the vulnerability of the resources.
The funds from the charge for water use need to be seen as a possibility to minimize the impacts of extreme events, shortages or excess water, from climate change. Measure the effectiveness of the charging through these indicators can help to focus investments and public policies in river basins.