Poster: Targeted Water Quality Assessment in Small Reservoirs in Brazil, Zimbabwe, Morocco and Burkina Faso
Targeted Water Quality Assessment in Small Reservoirs in Brazil, Zimbabwe, Morocco and Burkina Faso: water uses determine focus and methodology of water quality measurements by Eline Boelee, Lineu Rodrigues, Aidan Senzanje, Hammou Laamrani, Philippe Cecchi Background Physical and chemical parameters of water in reservoirs can be affected by natural and manmade pollutants, causing damage to the aquatic life and water quality. Small reservoirs are used for different purposes, making specific water quality parameters relevant and requiring specific methods to assess these. In 4 countries: Brazil, Zimbabwe, Morocco and Burkina Faso, small reservoirs were analyzed in different ways. Brazil – São Francisco Basin Zimbabwe – Limpopo Basin Main use of small reservoirs: irrigated agriculture Main use of small reservoirs: livestock watering, agriculture, brick Water quality concern: chemical contamination – from which origin? making, domestic, wildlife Approach: chemical analysis On-site chemical Water quality concern: organic pollution, ecosystem integrity analysis in Rio Preto Approach: questionnaire survey, plankton analysis in densely Findings: catchment, Brazil Water sampling at populated areas and national parks • Chemical contaminants were mainly of geological origins Mzingwane catchment, Zimbabwe Findings: • Nutrient inflow (fertilizer) from surrounding areas of intensive agriculture • Park reservoirs had higher variety of phytoplankton • Environmental issues • Community reservoirs had higher zooplankton abundance • Plankton may not be best indicator because of seasonal variation Morocco – Souss Massa Basin Burkina Faso – Nakambe Basin Main use of small reservoirs: domestic, livestock watering, Main use of small reservoirs: Agriculture, fisheries, agriculture, construction, wildlife livestock watering, domestic, brick making Water quality concern: organic pollution, salinity, hardness Water quality concern: toxic algal blooms Approach: participatory study, bacterial and chemical analysis Water sampling at Approach: analysis of phytoplankton and cyanobacteria Participatory mapping Findings: with farmers from Lac de Sian, Burkina Faso Findings: • Reservoir water too high levels of fecal coliform bacteria for Asgherkiss, Morocco • Cyanobacteria dominated phytoplankton human and animal consumption • High cyanotoxin levels in some reservoirs • Other sources insufficient quantities • Strong correlation between cyanobacteria, high human population densities and agricultural intensification Conclusions • Comparable findings from 4 countries • Main water uses provide good guidance for targeting water quality assessmentsContact: firstname.lastname@example.org • In absence of water quality monitoring programs, incidental measurements can help identify risk factors and potential interventions • Even in areas with low population densities, water quality is degrading • More complicated and severe water quality issues with increasing human and agricultural pressure • Water quality is threatening the ecosystem services of small reservoirs such as fisheries • Water quality management options are crucial for sustainable use of small reservoirs • Such options need to be developed for water resources planning and development as well as for communities managing their own reservoirs.