Methodology for Priorization of Control and Water Quality Monitoring: A Tool for Water Resources Management

Although Brazil’s pollution control scenario have been improving throughout the last decades, it is still far from satisfactory. One of several consequences for the lack of adequate monitoring on industrial discharges and public sanitation, more specifically wastewater transportation and treatment, is the water resources degradation, mostly in urban agglomerations. Moreover, scarcity in governmental investment for sanitation expansion and larger environmental oversight agents makes the situation become more stressful for water bodies and population. Hence the absence of money, regions must be prioritized in order to get the most out the investments.

The present paper aims to propose the development of a specific hierachization methodology for control and water quality monitoring as an optimized water resources management tool. The methodology validation was based on a study case at Piabanha watershed, an affluent to Paraíba do Sul’s watershed.

Combination of relevant environmental pressures combined to water quality mathematical model built the structure of the methodology. Among the environmental pressures were analyzed: water intake density and volume, effluent discharge density and volume and percentage of land usage (urban and rural areas). Given the fact the river modelled, Rio Piabanha, has a very large length-width ratio a one-dimensional water quality model was applied, more specifically, QUAL-UFMG, a QUAL-2E spinoff.

For each watershed region the combination of these aspects indicated the hierachization for water quality control and monitoring. Whereas regions with higher combination degrees demand more specific control and faster reaction, lower degree areas suggest that the activities can be less urgently planned.

According to the study results, a region near to the river spring and the initial/middle basin stretches require a high prioritization level. Monitoring and control actions must be accomplished in short and medium term, particularly the control of diffuse pollutant discharges and the main creeks: Quitandinha, Araras, Santo Antônio and Preto. From Piabanha’s downstream regions to debouch in Paraíba do Sul the priorization level is medium to low and must only be done after the most hierarchized regions achieve their goals.

This study’s methodology may support environmental protection actions, besides sanitation and industrial pollution control programs for current and planned water uses.