Pazhassi Dam Water Supply Disruption

Summary of Events Regarding Pazhassi Dam Water Supply Disruption

Key Facts:

• Heavy silt inflow into the Pazhassi dam caused by intense rain and landslips disrupted drinking water treatment, affecting supply in Kannur and surrounding areas on August 2, 2026.
• The Kerala Water Authority (KWA) reported that water quality issues stemmed from high turbidity due to excessive mud, not contamination.

Technical Details:

• Turbidity measured at around 125 Nephelometric Turbidity Units (NTU), while efficient treatment possible only below 50 NTU.
• NTU is a measure of water cloudiness based on suspended particles that scatter light; higher values indicate muddier water leading to reduced treatment capacity and quick clogging of filters.

Operational Insights:

• The Pazhassi treatment plant supplies approximately 30 million litres per day (MLD) to Kannur, Valapattanam, and Chirakkal.
• Water treatment was suspended after tests confirmed excessive turbidity on the night of August 1, 2026.
• KWA officials are conducting hourly monitoring of water quality, with plans to resume pumping once turbidity levels are deemed safe.

Causes and Implications:

• Landslides and heavy runoff in upper catchments from Karnataka have contributed to the turbidity issue.
• Ongoing rainfall may exacerbate the problem by sustaining elevated turbidity levels.
• KWA advises consumers to use stored water judiciously until normal pumping can resume.

Future Outlook:

• The disruption in water supply is anticipated to ease as turbidity decreases with a potential reduction in rainfall.

Environmental Impact:

• The event highlights the challenges posed by environmental factors such as rainfall and landslides on infrastructure and water supply systems.

This summary encapsulates the significant impacts and operational decisions made in response to the water quality issue affecting the Pazhassi dam, while emphasizing the importance of continuous monitoring and the environmental factors at play.