Limnological evaluation of water in the Rio Grande and Taquacetuba branches of the Billings Complex (São Paulo, Brazil) and management implications (doi:10.4136/ambi-agua.153)

Abstract

The large population contingent and the precarious urban planning in the metropolitan region of São Paulo have resulted in uncontrolled growth in areas where springs exist, generating strong pressures on the reservoirs. Concomitantly, a lack of articulation between public and private policy has led to various socio-environmental conflicts in the Billings watershed. This spring, which is responsible for the direct and indirect supply of water to millions of people, represents an enormous challenge for water resource management. In this context, this study aimed to analyze the seasonal limnological conditions of the Billings Complex, in particular the Rio Grande and Taquacetuba branches, and discuss the implications for the management procedure applied in the branches. Physical (water temperature, pH, electrical conductivity, suspended material, organic and inorganic suspended material) chemical (dissolved oxygen, total phosphorus and nitrogen, nitrate, nitrite, ammonium and inorganic phosphorus) and biological (chlorophyll-a) variables of the water were analyzed and the Trophic State Index was calculated. The results indicate a hypertrophic state in the Taquacetuba branch. The Rio Grande branch presented a mesotrophic state which is, however, artificially maintained due to copper sulfate and hydrogen peroxide treatments. The results are also discussed in light of CONAMA Resolution 357/2005. Levels of chlorophyll-a and total phosphorous in the Taquacetuba branch do not conform to the proposed class of use, class I. In this branch, monitoring must be intensified and measures adopted to reduce the level of nutrients in the main body of the Billings complex.

Heterogeneidade espacial e temporal de variáveis limnológicas no reservatório de Itupararanga associadas com o uso do solo na Bacia do Alto Sorocaba-SP

“…Desta forma, a eutrofização tem gerado grandes prejuízos e tem direcionado a atenção dos pesquisadores a esses ecossistemas aquáticos (Moschini-Carlos et al, 2010;Taniwaki et al, 2011;2013;Cunha et al, 2013a;Pedrazzi et al, 2013;Beghelli et al, 2015). A eutrofização artificial ocorre quando há disponível uma quantidade elevada de nutrientes no ambiente aquático, especialmente fósforo e nitrogênio (Camargo et al, 2003).…”

Is it possible to evaluate the ecological status of a reservoir using the phytoplankton community?

“…However, in 2016 the dominance of Cylindrospermopsis raciborskii was also observed in the Guarapiranga reservoir (Machado et al, 2016). The dominance of Cyanobacteria was reinforced in the Billings (Taquacetuba branch) indicating hypereutrophy, with high values of total phosphorus and chlorophyll-a (Moschini-Carlos et al, 2010).…”