Warnings and Alerts

Active warnings and alerts for Waihao River at Gum Tree Flat Road (Don's Hole)

Advisory Note - Rainfall‑Affected Water Quality

22 JAN 2026 By ENVIRONMENT CANTERBURY (KD)

Don’t swim in lakes, rivers, and beaches within 48 hours of significant rainfall! Swimmers are urged to stay up to date on the quality of their favourite South Canterbury/Canterbury lakes, rivers, and beaches to confirm they are safe to swim this summer. When you’re heading for a swim, don’t forget...
Toxic algae warnings for cyanobacteria in rivers

22 DEC 2025 By ENVIRONMENT CANTERBURY (KD)

HEALTH WARNING UPDATE ISSUED BY THE NATIONAL PUBLIC HEALTH SERVICE The National Public Health Service have issued a health warnings for toxic algae. The warnings follow detection of moderate to high cover of toxic algae (benthic cyanobacteria) in the:  Waihao River at Gum Tree Flat Rd (Don'...