Our river condition indicator will show one of three states depending on recent sewage discharge levels and river water volume:

RED
Extreme hazard to health.
Rowing & watersports not recommended. Abundant floating debris and suspended solids in river water. Poor quality water: Very low oxygen content; Extreme pathogen levels.
(This warning will be based on recomendations from the Health Protection Agency & Environment Agency).

AMBER
Water can present a high hazard to health. Abundant floating debris and suspended solids in river water. High pathogen levels. Precautions recommended to prevent ingestion, thorough washing after any contact. Extra care with cleaning open wounds and eyes. (Currently, this is the normal condition for the river, with weekly discharges of untreated sewage into the river from Combined Stormwater/Sewage overflows and Thames Water sewage treatment works).

GREEN
Water should be of low hazard to health.
Normal precautions to prevent ingestion for river users.
(We are unlikely to see this condition in the river under current sewage treatment methods. Treated sewage water discharged into the river still contains massive pathogen loads).