Mongabay · Natuur

Urban water quality poses challenges to low-income communities in Sri Lanka’s commercial capital

Low-income communities in Colombo, Sri Lanka, face challenges with water quality, relying on pipe-borne water that is increasingly contaminated. Extreme weather events and human activities are impacting water sources, forcing researchers to warn of potential reliance on less protected alternatives.

Most urban poor in Colombo depend on pipe-borne water, but many freshwater sources have become contaminated over the past 20-25 years due to human interventions and environmental factors. Researchers suggest that extreme heat may compel city dwellers to use alternative or less protected water sources, which studies indicate are more prone to bacteriological contamination.

Residents in low-income settlements like "Ranjan Wijerathnapura" rely on the National Water Supply and Drainage Board (NWSDB) for water. Despite drought warnings and requests for conservation, they must use tap water for daily needs. Many households lack water storage and are directly dependent on the utility, facing disruptions from routine water cuts and maintenance.

After water cuts, the water supply can turn muddy, necessitating the use of water filters, though not all households have them. Water safety in these urban low-income settlements is often overlooked.

Community water supply schemes, initially established in the 1990s for rural areas not covered by NWSDB, were often sourced from natural springs and streams that were not contaminated at the time. However, 20-25 years later, development, agricultural expansion, and livestock farms have led to contamination, requiring water purification.

The Department of National Community Water Supply (DNCWS) registers community-based organizations managing these schemes and has initiated new ones since 2019, with a target completion by 2027. The NWSDB reports no challenges in meeting Colombo's daily water demand of approximately 1 million cubic meters, ensuring regular supply except for rare emergencies and maintenance.

Access to NWSDB water supply in the Western province has increased, but a substantial number of households still depend on other sources like wells and community schemes. These sources require regular monitoring and household precautions, as they are more likely to show bacteriological non-compliance, posing a higher risk if proper treatment and storage practices are not followed.

The Sri Lanka Standards Institution (SLSI) sets drinking water quality standards. Purification methods include chlorination for bacteria, filtration for mud, and complex systems for heavy minerals to meet local standards.

Sri Lanka's vulnerability to extreme weather events like floods, droughts, and unseasonal rainfall impacts water availability and quality. Flooding can introduce sewage, animal waste, and solid waste into surface water sources, and contaminate dug wells. During droughts, water scarcity can force people to use less protected sources.

Major reservoirs are currently at 55% capacity. While domestic water consumption is manageable, limited conveyance capacity hinders NWSDB's distribution of safe drinking water. The NWSDB has a drought management plan, including groundwater extraction and emergency water supply via bowsers, which has assisted over 70,000 people.

Rising utility costs present a challenge for low-income residents. Water tariffs were revised in 2024, with rates for low-income settlements ranging from 100 to 1600 rupees per unit. Despite minor reductions in the 2024 revision, residents report little relief following significant tariff hikes in 2023. A special audit report highlighted management weaknesses within NWSDB contributing to tariff increases, with domestic consumers generating the highest revenue.

AI-samenvatting op basis van de bron.