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Abstract

Effects of urban drainage on the physico-chemical and biological characteristics of surface water in Conceição Lagoon (Florianópolis, SC, Brazil). The proximal and distal surface waters from the drainage
outlets in Lagoa da Conceição – Conceição Lagoon – (27º34’S e 48º27’W) were sampled and characterized according to their physico-chemical and biological characteristics between April 2001 and March 2002. It was
found that urban and pluvial drainage influenced the characteristics of the water column of the lagoon in relation to silicate and dissolved nitrogen. Through the dynamics of biogeochemistry, phosphorus was excluded
from the dissolved form, and no expressive differences between the studied areas were observed. Also, the particulate matter did not present any alterations directly determined by the drainage into the lagoon, which
could be considered as punctual at the surface water. The physical dilution process was significative for the differences of the concentrations of silicate and nitrate between areas that were proximal and distal from the drainage.