Modeling historical changes in nutrient delivery and water quality of the Zenne River (1790s–2010): The role of land use, waterscape and urban wastewater management

The Seneque/Riverstrahler model has been used to explore the effect of human-induced changes in drainage network morphology and land use on organic and nutrient pollutions, for the last 20 years and back to the 1890s and 1790s. With the development of human civilization, past environmental constraints differed compared to today. Research has sought to reconstruct (i) point sources (domestic and industrial), using statistics and archives from these periods, and (ii) diffuse sources via landscape and riverscape analysis based both on maps and agricultural statistics from the periods concerned.This study shows that a maximum of pollution occurred in the 1890s at the height of the industrial period, due more to the industrial load than to the domestic load. This substantial organic and nutrient pollution might have lasted up to very recently, when the Brussels Northern wastewater treatment plant began operation in 2007, significantly reducing the organic and nutrient load of the Zenne River, returning to a background pollution level assessed herein for the 1790s before industrialization expanded.

► The treatment of Brussels waste water effluents on water quality was evaluated.
► Historical pollution was reconstructed and retrospective water quality modeled.
► The effect of waterscape (ponds) was explored for their ecological role.
► Industry and land use in the past was shown to be enormously polluting.