A community based initiative in Sri Lanka to keep our natural environment clean

Thalangama Wetland Watch

Wetland Watch


Working hand-in-hand with the Irrigation Department

May, 2018

How many hyacinths can a boat carry?

March, 2018

Removing the plants from the lake is the first job. The second job is to empty the boats, and the third the transport of the plants to their destination, here a neighboring tree plantation which receive about 20 cubic meters of fresh hyacinths which are an excellent fertilizer.

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Snapshots from 31 March 2018

The Thalangama Wetland Watch received strong support from the Rotaract Club
of Colombo in cleaning our wetlands from trash and water hyacinths.

Spontaneous community protest helped to prevent illegal dumping of
construction waste in our paddy fields.

Fighting Water Hyacinths.

February, 2018

February 2018 started with emphasis on the quickly spreading water hyacinths on the Thalangama lake. With active support from the CEA and its staff, and endorsed by the Irrigation Department, a group of local residents and interns from the International Water Management Institute (IWMI) started on 10th of February the removal, an activity that is labor-intensive and will continue over many of the coming weekends, depending on the availability of volunteers.

The water hyacinth is an invasive alien species and one of the worst aquatic weeds in the world, able to cover whole lakes within a few months. Native to Brazil and other South American countries, the plant was introduced in Sri Lanka in 1905 as an ornamental plant from Hong Kong. The recent dredging of the Thalangama lake brought many nutrients from the sediment back into the water which supports the growth of the weed. With increasing surface coverage, the plant can easily overtake the habitat of native plants, lower the oxygen levels in the water and kill fish. The Thalangama lake has already very low dissolved oxygen levels between 1 to 4 mg/l (compared with a minimum threshold of 3 mg/l) which does no longer support most species of fish. Please help us getting this weed under control.

17/18 February – 2nd weekend tackling water hyacinths.
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Collecting several truckloads of hyacinths for composting.
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On the third weekend, the impact of the work became visible. Several “islands” of water hyacinths are gone..

Fourth February weekend addressing Water hyacinths and Salvinia (watermoss)

Special attention to the Averihena Wewa, 14-21 January.

January, 2018

To support the flow of flood water from the Thalangama tank to the Averihena tank, and from there towards the Kelani river, the outflow of the Averihena tank currently undergoes rehabilitation work to improve bank protection towards the Athurugiriya Road. Our attention focused on the stretch from the lake to the Amaragoda Road (see map).

With kind support from lake neighbors and the local construction company, a boat and raft could be used. In total, 10 members of the local community, four IWMI staff/interns, and several members of the Wetland Watch core group supported the activities. The focus was on the lake itself, its outflow (canal) towards the Amaragoda Road, local tributaries, as well as the new road along the canal where large amounts of mud (mixed with trash) are deposited from canal dredging.

Cleaning the lake with kind support of participants.
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Cleaning the lake with kind support of participants.
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Between 14 and 21 January, about 95% of all visible waste was removed resulting in approximately 60 bags with cans, bottles, styrofoam (regifoam), buckets, plastic bags of all sizes, flip-flops, etc. Waste transport was supported by IWMI. One part of the waste was sorted into different recyclables straight away and handed over to the local waste management service, the rest will be sorted over the coming days.

Collected trash..

The trash cleaning along the outflow of the Averihena lake continues every week by local residents with increasing emphasis on tributaries from local settlements. Bamboo barriers are now planned to stop floating trash and simplify its collection.

Cleaning the less accessible parts of the lake..

December, 2017

Cleaning the less accessible parts of the lake with in-kind support of the small boat house.

…while struggling with the regular dumping of larger bags full with diapers in the road-side canal along the lower Udawatta Road, branching off Pothuarawa Road. Water-soaked diapers are extremely difficult to manage.

Celebrating one year of Wetland Watch..!

November, 2017

Working hand in hand with the authorities.

We are celebrating one year of Wetland Watch! Since Nov 2016, our two lakes are – as far as possible - ‘free of plastic and other waste’ and also more than 3 km of the surrounding environmental protection area are regularly monitored and cleaned. Especially in our core area along the two lakes, no new waste gets older than a day. We are proud as this was possible without any external funding, following the motto “If it is to be, it is up to me”.

We are removing - on average - one 90-liter bag of trash per day, generated by lake visitors who enjoy the serenity but unfortunately ‘forget’ their trash of which volume-wise half consists of recyclables (like beer cans, paper, glass and PE bottles). We counted more than 120 glass bottles over three weeks of collection just around the lake. There should be a cash refund also on smaller Arak bottles! In addition, there are every second week a few large bags of diverse waste materials from small industries, shops or households dumped deliberately in drains or the bush, usually after sunset. Also these materials are sorted to recover recyclable resources but also screened for anything which could lead to their source.

Recovered resources from one week of collection.

Looking back at our first year, we like to thank our main partner, the local authority in charge of waste collection, as well as all those who contribute to Neill’s allowance for his daily cleaning job, as well as the about 100 local residents and visitors who regularly express their appreciation for the work.

Looking forward, more educational efforts are needed, and for the sustainability of our work, we need more active members to share tasks and responsibilities. Our main collectors are already over 55 years old; younger volunteers are welcome!

Another success of tracing polluters.

October, 2017

Dumped and again removed waste.

October started with another success of tracing polluters. Just next to the main recreational spot at the Thalangama lake, a truckload of construction waste was dumped overnight (see photo). Fortunately, the pile contained clear evidence leading us to its source, and the responsible estate developer apologized and removed the pile within 24 hours.

Waste that can kill..

A different challenge was observed at Udawatta Road where a so far unknown hairdresser dumped several bags of saloon waste which did not only contain large piles of human hair, small cosmetic bottles etc., but also many razor blades. These blades are not only a threat to anyone removing the waste, but like plastic bags also to our roaming cows which are magically attracted by any waste pile.

Extending the drain cleaning on Parliament Road.

September, 2017

Drain cleaning area
(stretch between the two yellow pins)

On 9th and 10th September, the team extended its cleaning efforts along Parliament Road (see July 2017) to cover now 370 m of the main drain from Pelawatte junction beyond the Ministry of City Planning and Water Supply. This part of the drain is less suffering from indiscriminate dumping, but accumulates in particular plastics washed by storm water towards Parliament lake. Especially the plants in the drain function like a "bar screen" for floating plastics. Again, this was a ‘special action’ aside the routine monitoring and cleaning of the Thalangama lake area.

Lower drain section with "natural plastic screen"

Middle stretch at the ministry

Preventing waste to reach the Diyawanna lake.

July, 2017

With the growing waste problem interlinked with the outbreak of dengue fever in Sri Lanka, a team of volunteers (including several IWMI staff) supported by local community members, did a clean-up of the dirtiest 150m of the drain opposite IWMI-HQ, from Pelawatte junction towards the Ministry of City Planning and Water Supply. Several hours of cleaning was done on July 15 and on July 22, the vegetation was cut, several cubic meter of trash collected, sorted (PE, metal, glass, etc.) and handed over to the authorities. Residents in the locality expressed their sincere appreciation and praised it as a positive example. Cleaning is now being repeated every other weekend.

Udawatta Road, along the Thalangama Environmental Protection Area.

March, 2017

Along the early parts of Udawatta Road (starting from Pothuarawa Road direction Malabe), folks start dumping larger bags of trash on both sites of the road: On the left side of the road under some trees bordering the Thalangama paddy fields and on the right side of the road into the drain which supplies the paddy with irrigation water. As a result, water quality and flow decreased, plants took over, and residents complained about the increasing mosquito numbers. With support of the local waste management department supervised by the Environmental police, dumping place and drain were cleared over two days of hard work. Since then, about 350 m along both sides of the street without housing are cleaned by us once a week. The drain is now flowing again, signboards were erected, and local residents reported less mosquitos. However, the area remains difficult to monitor as parts of the road are hidden between trees and illegal dumping continues. As this is the most Northern part of the area we adopted for cleaning, it would be ideal if another team of residents living closer to the street could adopt this stretch along the Thalangama Environmental Protection Area.


December, 2016

Illegally dumped waste

As a special holiday action, several cubic meters of waste were collected on Christmas eve (24th December 2016) on just 140 meter of the Pothuarawa Road where it is crossing the Thalangama paddy fields between Battaramulla and Malabe. As there are no residential plots on both sides of the road, many folks used the area including its water bodies for illegal waste dumping of usually larger mixed waste bags, construction waste, old TVs, etc. The Wetland Watch team worked 12 hours on these 140 meters to collect the waste, sort it into recyclables and remove it. Passing cars supported the efforts by donating drinks and food. We also fenced parts of the road where most waste was dumped and installed a series of signboards against illegal dumping. Since this action in December, the road over the paddy fields is regularly serviced by us to prevent any new waste accumulation.

Collected waste

Half of the collected recyclables
mostly PE & glass bottles)

The beginning.

September to December, 2016

Weekly collection of trash around the Thalangama lake started in late 2016 as a family activity. Involving our children in the cleaning efforts gave opportunity to give them some fresh air, as well as for environmental education, from water pollution to plastic recycling, or on the sense of community service. And the amounts of collected waste over just a few hours were every time astonishing and a real achievement as the photos show.

Realizing that weekly efforts would not be sufficient to keep the area clean, our efforts became more serious in December when Mr. Neill Burke joined the initiative as full-time assistant, supported financially by about ten community members. At the same time, also the collaboration with the official waste collection operators intensified and the sorted waste gets since then regularly removed from our collection points.

Collected waste