Construction work in the last phase.
The construction work at the main bridge is coming to an end. After a break during the covid-19 curfew, the construction activities resumed. The iron pillars have been removed, trees have been planted, and the last work concerns the opening devices for the weirs. Once finished, the lake will be able to release more water for paddy cultivation while serving as storage reservoir for heavy rains.
Stakeholder meeting on NAQDA proposal
In June 2020, the National Aquaculture Development Authority (NAQDA) proposed a plan for the removal of alien fish species from the lake and the development of coordinated fish/shrimp farming activities, with potential for commercialization. As commercial fish farming would undermine the status of the lake as an officially declared (23/Feb/2007) Environmental Protection Area (where only traditional fishing is allowed), most lake stakeholders did not support the plan. They also noted that for any proposals, all relevant authorities should be consulted as stated in the National Environmental Act #47 of 1980. NAQDA acknowledged the feedback and agreed to consider an alternative location.
A good fisherman is first of all an ecologist.
The two lakes are enjoying a popularity like never before!
While the Covid-19 curfew limited the movements of individuals and families, the Averihena and Thalangama lakes offered a safe haven for recreational evening and weekend walks which was appreciated by many more people than at any time over at least the last 5 years.
New floodgate soon in place.
- The construction work at the bridge (see Recent construction work) is now well advanced. While neither weekends nor holidays could stop the work, the current Corona curfew finally gave the workers a break.
Stairs into the lake for those who like to swim
New Floodgate to release water before larger rain events
that the lake can absorb more storm water
Reinforcement of the drain connecting the Thalangama and Averihena lakes, to withstand the water
passing the floodgate (see the end of the two tubes on the right).
Photo taken from the bridge
The World Wetlands Day 2020
The World Wetlands Day 2020 was celebrated in Colombo on February 2 and 3. While a major clean-up of 20 wetlands of Colombo was coordinated by the Sri Lanka Land Development Corporation (SLLDC), high-ranking dignitaries met at the Thalangama lake for a tree planting ceremony. The Thalangama Wetland Watch contributed actively to both events.
A national wetland camp was held at the Averihena lake in the Thalangama Environmental Protection Area on 17th and 18th January 2020 with the participation of environmental pioneer students. Mr. S Amarasinghe, Chairman, CEA, Mrs. Kanthi de Silva, Deputy Director General EMA division and other officials participated in the event which accompanied the National program of the World Wetlands day.
- The Thalangama lake struggled with an invasion of Salvinia, covering at times more than 70 % of the lake’s surface.
- Salvinia is a free-floating aquatic fern. The floating leaves have dense stiff hairs on the upper surface, whereas the submerged leaves function like a root and serves as nutrient absorbing organ.
After heavy rains, large parts of the Salvinia carpet moved towards the spillover in direction of the smaller Averihena lake. Directly behind the spillover, a “mountain” of Salvinia built up like foam.
To get the plants moving, volunteers tried in different ways to help (see LATEST NEWS ON OUR WORK).
The local construction company pushed the Salvinia further down the channel where it got stuck again, in particular at the entrance of the shallow Averihena lake.
The Ministry of Education visited the Thalangama lake several times in July to train teachers in water sampling and analysis.
Re-launch of the construction work
The largest impact on the lake will have the construction of a new flood gate near the circular overspill. See here for more details. Once the construction will be over, the area near the overspill will be set up in a family friendly way with stairs into the lake.
The construction work along the lake also brought us a new excellent road cover and vehicles driving with higher speed than ever before. Especially the biker community will be excited but hopefully not endanger other lake visitors, residents, livestock and themselves.
Rajagiriya – Athurugiriya Elevated Highway Project.
The Road Development Authority (RDA) and the Central Environmental Authority (CEA) continue discussing options for the proposed elevated highway which will in one or another way affect the Thalangama wetlands. The challenge is to balance social, economic and environmental impacts.
DailyNews.lk: Impasse over proposed route
See also: http://www.mohsl.gov.lk/
- It is obvious from the two maps (shown in this update) that the elevated highway will pass the whole upper (paddy field) part of the protection area, independently of the two alternatives near the Averihena lake.
- The Averihena lake is a reservoir and flood retention area between the Thalangama tank and the Kelani river (more..)
- The Thalangama wetland area was declared an Environmental Protection Area by Gazette Notification No.: 1487/10 Dated: 2007.03.05.
- Resources from CEA: Slide | Web
TV drama shooting at the Lake.
President calls Navy to help paddy farmers getting more water.
One year after the World Bank supported dredging of the Thalangama Lake ended, some farmers further away from the tank are not yet satisfied with the result. In contrast to the World Bank project which followed a broad stakeholder consultation and an environmental impact assessment, before the actual work started, the Navy responded with machinery within days of the call, supported by the Kaduwela Municipal Council. A large number of concerned citizens, including the Thalangama Wetland Watch discussed with the Irrigation Department the need to involve CEA to assist the Navy in a balanced approach which should not harm the internationally recognized flora and fauna of the Environmental Protection Area, and in particular the bird resting places. In a first meeting, the Irrigation Department expressed its interest to use the opportunity of the moment to restore the ancient lake size by dredging the marshland in the back part of the current lake which would however seriously affect wildlife and lake water quality (as the wetland is a natural wastewater treatment system) if not done with buffer zones and clear expert advice. A careful approach is supported by the fact that Colombo just received international accreditation as a “Wetland City” under the Ramsar Convention, with strong support by the President. In this regard, the community responded to the President with a letter.
Update: With regard to the expressed needs by farmers for more irrigation water, CEA, Irrigation Department, and Navy formally met in February to discuss the way forward. The Irrigation Department is currently (March 2019) performing a lake depth survey to prepare a work plan for CEA approval. Once approved, the Navy will return to the lake.
Signboard Explosion at the Thalangama Lake.
There are some signboards at the Thalangama lake with useful information on the environment and good practices for visitors.
Traditional Devil Dancing and Diya-Kepeema ritual.
Tree planting around the lake.
There were recently again much appreciated initiatives of tree planting around the lake. More trees will have multiple benefits aside replacing trees which died or were deliberately cut down.
However, different initiatives apply different techniques and also different levels of post-planting care as the photos show. In the worst cases, planted trees died straight away or where within a few weeks completely covered by climbing weeds. As a result, the planting success rate varies a lot and it would be good if the different initiatives could learn from each other.
Government officials in action.
The search of a knife which was used in a severe crime on the bottom of the Thalangama lake attracted many curiosity seekers, watching divers and police in action.
New signboards were installed by the Irrigation Department, with information about the Thalangama tank and on correct behavior to maintain human and environmental health.
The spillover nearly disappeared under heavy rains in May 2018.
April & May, 2018
A lot of ‘bad parking’ (poor driving) in April and May 2018
World Bank published a brief.
"In response to devastating floods, the government of Sri Lanka has prioritized urban wetlands management in the Sri Lankan capital Colombo as a key pillar of its climate and disaster resilience strategy."
More activities in the lake
Lake baptism on March, 25, 2018