A study of the water quality monitoring programs across six water supply reservoirs and three water authorities (Redland Water and Waste, Gold Coast Water, SEQWater) in southeast Queensland has found considerable differences in the parameters measured, and sampling protocols. In order to more effectively compare water quality in the reservoirs, a study is planned to sample the reservoirs using the same sampling protocols, timing of sampling, parameters measured and analytical techniques. This will allow a more direct comparison and aid the industry in identifying the factors responsible for promoting algal blooms in reservoirs. Preliminary analysis of the historical data for water quality parameters (relevant to algal bloom problems) showed that total nitrogen and chlorophyll a concentrations were highest in reservoirs with catchments having the highest percentage agriculture (North Pine, Somerset and Wivenhoe Dams). In contrast, total phosphorus did not show this trend but was highest in the catchment with the highest urban development (Leslie Harrison Dam). Further analysis of the historical data is warranted to compare catchment characteristics with water quality.