Climate change and local anthropogenic activities have altered river flow regimes across Canterbury, New Zealand

River flow regimes influence ecologic, cultural, social, aesthetic, and economic values. Detecting changes in river flows attributing their causes is important but challenging due to the combined of climate relevant local activities, lack data on water abstraction, drainage modification or land use management. This study assessed degree which trends could be attributed versus anthropogenic activities across Canterbury, Aotearoa New Zealand. Trends were for a period that started immediately after change regulatory regime 1991 ended 2020, coincided with increases abstraction management practices. observed summer conditions indicated rainfall was stable, temperature increased, decreased many sites during period. Models representing as function trained tested using cross-validation an earlier baseline Predictions 1991–2020 made models used account effect climate. The difference between predicted activities. Decreases partially associated climate, several catchments also findings indicate both have alter regimes, suggesting hydrological impacts should considered alongside when making decisions.