Intense rainfall and landslides have caused high turbidity in the Pazhassi dam, disrupting the drinking water treatment process for Kannur and surrounding areas.

Key Takeaways

  • Heavy silt inflow due to intense rain and landslides has spiked turbidity in the Pazhassi dam.
  • Water treatment at the Pazhassi plant has been suspended to prevent filter clogging.
  • The disruption affects a daily supply of 30 million litres to Kannur town and nearby areas.
  • Turbidity levels reached 125 NTU, significantly above the safe 50 NTU threshold.

The drinking water supply to Kannur town and its adjoining areas has faced significant disruption following heavy silt inflow into the Pazhassi dam. The surge in turbidity, triggered by intense rainfall and landslides in the upper catchment areas, has forced the suspension of treatment processes at the Pazhassi water treatment plant.

According to officials from the Kerala Water Authority (KWA), the issue is not chemical contamination but rather an unusually high concentration of suspended mud particles. On Saturday night, tests revealed turbidity levels hitting approximately 125 Nephelometric Turbidity Units (NTU), whereas the plant requires levels to be below 50 NTU for efficient and safe treatment.

Why This Matters

BozokMedia analysis shows that such disruptions highlight the vulnerability of urban water infrastructure to environmental shifts. High turbidity levels don't just make water look muddy; they pose a mechanical risk to filtration systems, causing them to clog rapidly and necessitating a complete halt in operations to prevent long-term damage.

When turbidity is very high, the treatment capacity drops sharply and the filters clog quickly.

The Pazhassi treatment plant is a lifeline for the region, supplying nearly 30 million litres a day (MLD) to Kannur, Valapattanam, and Chirakkal. KWA engineers are currently monitoring water quality on an hourly basis, waiting for the silt to settle before resuming pumping operations.

Historical Background

The catchment areas feeding the Pazhassi dam, parts of which extend into forested regions of Karnataka, have increasingly become prone to landslides during monsoon seasons. This recurring issue of siltation is a growing concern for water management authorities across the Western Ghats region.

Did You Know?: NTU, or Nephelometric Turbidity Units, measures how much light is scattered by particles in water; higher numbers mean cloudier water.

Frequently Asked Questions

1. Is the water supply contaminated with toxins?
No, officials state the issue is high silt/mud content (turbidity) rather than chemical contamination.

2. When will the water supply return to normal?
Supply is expected to normalize once rainfall subsides and turbidity levels drop below the 50 NTU limit.