Discussão sobre a importância dos serviços ecossistêmicos para a gestão dos serviços de abastecimento de água

Abstract

The lack of scientific knowledge in policies, plans and programs related to basic sanitation and water resources is a risk for the preservation of many extremely endangered regions and for the management of natural areas that can be exploited in the near future. The modification of the hydrological regime is one of the most important anthropogenic changes in the environment, with important consequences in the level of lotic ecosystems (running water), especially when originated by the construction of dams. However, decision-makers have rarely acted with regard to the topic when it comes to water basin drainage standards. Initiatives in Europe, the United Kingdom, the United States and Costa Rica are introducing new approaches needed to complement existing water management and water supply practices and make use of the ecosystem services (ES) concept to achieve better management of such services. Thus, international governments are showing interest in encouraging investment in the protection of ESs, with paying for them becoming a tendency. Meanwhile, in Brazil, water resources and basic sanitation policies, plans and programs do not take the ES concept into account. In the state of Bahia, the same thing is happening, as can be seen in the Metropolitan Region of Salvador Water Supply Plan (PARMS), where the solutions for supplying water to the Metropolitan Region of Salvador (MRS) are structured in a manner that does not allow for hydrological connectivity and interferences in four water basins. The PARMS alternatives involve structural measures, with alternatives of interventions in the hydrographic basins consisting of water fragmentation, aquifers and reversal of basins to boost the supply of water, and structuring measures for plans and programs. The ESs should be observed to the extent that the federal basic sanitation and water resources laws include water abstraction as a component of potable water supply and water use fees. Changes in ecosystem functions due to water intake and subsequent effluent discharge are not included in the regulatory framework for basic sanitation in Brazil. Due to the above, the aim is to contribute to a paradigm shift towards the incorporation of the ES concept in the policies, plans and programs of water resources and basic sanitation in Bahia that could lead to the creation of a specific law to encompass the ecosystem functions. This is true for the specific plans for the drinking water supply component and in the municipal basic sanitation plans (BSPs), foreseen in Law 11.445/2007 and obligatory for municipalities that are the service suppliers and have a closer relationship with the reality of the water basins, or even the government programs that spell out the need for ES preservation, including ES payment programs, as in the UK, adding monetary value. There is a need for further studies on the subject, but the discussion regarding water supply effective management and service aimed at maintaining biodiversity, habitat, plant cover of rivers and water production is both important and indispensable.