The Source Apportionment Geographical Information System (SAGIS) is a discrete digital information management and visualisation platform, based on ArcGIS software, which serves as an integrated system for modelling water quality in rivers and lakes. SAGIS operates in conjunction with the Environment Agency’s SIMCAT water quality model, together referred to as SAGIS-SIMCAT. 

UKWIR produced this model in collaboration with the industry’s environmental regulators - Environment Agency, Natural Resources Wales and the Scottish Environment Protection Agency - and continues to work with them on its development. 

In the most recent round of business planning, SAGIS outputs have served as the

main evidence base for identifying wastewater treatment works improvement schemes. SAGIS-SIMCAT is now firmly embedded within business-as-usual processes and serves as the environmental regulators’ primary catchment planning tool.