Rainwater Harvesting & Filtration Systems in Polonnaruwa – 2021

Date: October 2022
Location: Polonnaruwa District, Sri Lanka

Overview
Partnering with three primary schools in Polonnaruwa, MPF designed and installed comprehensive rainwater-harvesting and gravity-fed filtration systems to guarantee safe drinking water on campus year-round.

The Challenge

  • Seasonal water scarcity: Schools faced acute shortages during the 4-month dry season.

  • Unsafe sources: Reliance on open wells and tanker deliveries led to frequent water-borne illnesses.

  • Maintenance gaps: No local capacity to service or repair water infrastructure.

Our Approach

  1. Roof-Catchment & Storage

    • Fitted 200 m² of rooftop gutters per school, feeding into 10,000 L polyethylene cisterns.

    • Designed overflow and mosquito-proofing features to meet WHO standards.

  2. Multi-Stage Filtration & Treatment

    • Implemented sand-charcoal filters followed by UV-LED sterilizers for >99.9% bacterial removal.

    • Added inline TDS monitoring and auto-flush valves to maintain filter efficiency.

  3. Community Engagement & Training

    • Launched “Water Guardians” clubs: 150 students trained in daily quality checks and basic upkeep.

    • Conducted quarterly workshops for school caretakers on cleaning protocols and part replacement.

Implementation Highlights

  • Harvest systems collected up to 8,000 L/month during monsoon peaks.

  • Independent lab tests confirmed 99.9% removal of E. coli and coliform bacteria.

  • Local mason cooperatives fabricated cistern platforms, boosting village incomes.

Results

  • Zero reported water-borne illnesses in the first school term post-installation.

  • 75% reduction in tanker-water expenditures.

  • Neighboring communities have replicated the model for home installations.

“Our children drink safely every day, and they proudly maintain ‘their’ system.”
— Headmaster, Galnewa Primary School