Tainted waters

Indiscriminate dumping of sewage, waste and industrial effluents has rendered Kelani River one of the most polluted:

by Dhaneshi Yatawara

Flowing through the city of Colombo the Kelani River is an invaluable source of fresh water. Yet, sewage waste, industrial effluents, unused batteries and various poisonous and polluting substances are dumped or discharged into this magnificent water course rendering it one of the most polluted.

The Kelani River is the primary source of drinking water of millions of people living or working in Colombo. According to the IUCN, 25% of Sri Lankans live in an around the Kelani River basin, while a large number of industries and businesses depend on its water but the continuous dumping of sewage, waste and industrial effluents, has made it one of the most polluted rivers in Sri Lanka. Over the years, Kelani river basin land use has changed significantly, further increasing the levels of water pollution.

Microbiological contamination and turbidity are the main sources of pollution in the Kelani River, according to a recent survey conducted by the Central Environmental Authority (CEA). It also identifies Welivita in the Kaduwela electorate as having the best water quality. The survey also mentions that the water quality at Thulduwa and Seethawake areas proved inferior, compared to the lower reach of the river. The Seethawake Industrial Zone continuously releases its effluent to the river waters.

The CEA had tested the water at seven sampling sites of the main river and five sampling sites from its tributaries, 58 km away from the river mouth, towards Avissawella. The worst quality was reported from the sampling sites at Raggahawatte, which was contaminated with industrial waste generated by the Biyagama Industrial Zone.

Industrial effluence

According to the surver, sampling sites located in the middle of the river at the Pugoda Ferry, Hanwella Bridge and Kaduwela Bridge have shown better water quality. It is believed water from the tributaries might be diluting the waste concentration.

The Ambatale water supply intake point is located about 14 km from the river mouth. Yet, sewage from the nearby settlements is discharged to the Kelani River. The industrial effluents, when added, further aggravate the problem.

Tanning, metal finishing and processing industries are located close to the Kelani river basin, all of which contribute to the river pollution. To prevent further deterioration of the water quality and to protect the Sri Lankan fresh water resources, a water safety planning is necessary for many river basins in Sri Lanka, experts say.

The CEA and the IUCN have initiated the Kelani River Basin Multi-Stakeholder Partnership (KRMP) for water safety planning the agreement for which was signed between IUCN and CEA on May 19.

Water safety

Due to the multi-sector nature, the technical guidance is obtained from a range of key agencies such as Land Use Policy Planning Department, Urban Development Authority, CEA, National Water Supply and drainage Board (NWSDB), Coast Conservation and Coastal Resource Management Departments, 14 local authorities, Board of Investments (BOI), National Building Research Organization (NBRO), Department of Agriculture and several universities, among others.

In addition, a number of international river basin restoration experiences have been emulated, to strengthen the KRMP effort. "Once developed and implemented successfully, all or some of the approaches used in this project can be used in other water quality, water safety and river basin related interventions," explains Dr. Ananda Mallawatantri.

IUCN Country Representative

Following the initial study of the KRMP 20 identified places along the Kelani River Basin have been earmarked by the project for having different environmental problems. "When conducting the ground level study, initial data was available with the NWSDB and CEA, collected over five years by their regional stations. We added a few more technicalities to determine more details of the nature of problems faced by the river basin," Dr. Mallawatantri explained.

An action plan is being prepared by the CEA. "Technical expertise available within the country is adequate. The problem is to get these agencies sit down and work together, long term. The KRMP has been successful in these attempts," he said.

Severe damage

Gem mining and river sand mining have caused severe damage to the river bed, further increasing the turbidity of the water. "The main focus is to minimize these activities by getting local peoples' assistance, including sand miners and gem miners, involved in the project at the community level. Promoting alternative livelihood development activities is another key aspect," said Director General of the CEA, K.S. Muthukudaarachchi.

Adding to the current complications, salt water intrusion to the Kelani River from the ocean has begun to further deplete the water quality, said Muthukudaarachchi. Several times, the 'salt wedge'- a separate layer created in the river water mass with salt water -had extended up to the Ambatale water supply intake point, making the water unsafe for drinking and domestic use.

A new threat is also looming large, according to experts.

Dr. Mallawatantri said, the sea level rise caused by global warming can worsen the salt water intrusion to the rivers. "Therefore it is critical that we prevent river basin pollution before it gets to an irreversible point," he cautioned.