Renovation work on 12 reservoirs in full swing

by Gamini WARUSHAMANA

Renovation work on 12 major reservoirs has been carried out by private and state sector contractors under the Dam Safety and Water Resources Planning Project (DSWRPP). Thirty two major reservoirs have been selected and are scheduled to be completed by 2013.

However, the implementation of the project is behind schedule due to various reasons and the Ministry of Irrigation and Water Resource Planning has sought an extension of another two years. The ministry expects to renovate several major reservoirs in the North and East with additional funding.

The sluice gate of the Tabbowa tank

The project is funded by the World Bank and Rs.7,652 interest free credit facility has been provided. DSWRPP recently organised a media field tour to demonstrate the progress of Tabbowa, Inginimitiya and Usgala Siyabalangamuwa tanks in the North Western province.

A part of the Tabbowa project is nearing completion and the progress is satisfactory, said the Irrigation engineer of the Puttalam district R.C. Jayasinghe. Construction work has been outsourced to a private company and the agreement was signed in February this year.

The left bank sluice gate has been reconstructed and spill gates are under construction. The North East monsoon rain has started and it will slow down construction work for several months if heavy rains continue. Renovation of the inner side of the dam and the right bank sluice gate has to be postponed to April 2012 as the tank had to be filled for the coming Maha season.

A service road has been constructed along the dam and renovation of the downstream will begin shortly. Jayasinghe said renovation work of the downstream will not be affected by rain. However, construction of the inner side of the dam and the right bank sluice gate cannot be done without emptying the tank, he said.

The project has taken into consideration social and economic issues faced by the community who depend on the irrigation systems of the tanks. The renovation work is carried out without affecting Yala and Maha seasons. However, in some sub projects the Yala season will have to be abandoned.

The project has extensive plans to mitigate the socio economic impacts on the community in such circumstances, it will provide alternative crop plan, livelihood support and other services during that time.

Bureaucratic bottlenecks within state agencies are the main stumbling block in fulfilling the tasks on time, irrigation engineers and private sector contractors said. Long procedures have to be followed to obtain approval from various government agencies that take an unbelievably long time. This has created various issues in the implementation of the projects. For instance the Tabbowa tank is owned by the Department of Wildlife and it needed the approval of the department to get soil from the tank bed to fill the dam.

It took four months just to get approval. Again it took another month to get approval from the Geological Survey and Mines Bureau. Jayasinghe said that before 2002, the Government Agent of the district had the power of the Forest and Wildlife departments and therefore it was convenient to implement government development projects.

Today we have to reach the top level of each department and the process is complex and time consuming, he said.

The Tabbowa tank has 350,000 acre feet capacity but it cannot be filled to full capacity as the dam, sluice gates and spill gates are dilapidated. As a result over 700 acres of paddy lands have been abandoned. There are water seepages at several points along the 1,300m long dam and the people in the downstream areas live in fear when the tank reaches full capacity during the rainy season. The estimated cost of the Tabbowa tank renovation project is Rs.250m.

Inginimitiya is a relatively new tank where construction work started in 1981 and was completed in 1985. Since then it has not undergone any major repair work.

The Irrigation engineer of the Inginimitiya project, M.A.S.S. Gunasena said that this is the first time that major renovation work has been undertaken. There are three sections to the renovation; civil engineering, construction of the dam and mechanical and electrical engineering work of the spill gates.

There are seepages in the dam and the metal spill gates constructed 25 years ago have eroded. The present mechanically operated spill gate system will be developed by installing an electrically operating system, Gunasena said. The estimated cost of the renovation is Rs.80 m and 20 percent of the renovation work has already been completed.

The capacity of the Inginimitiya tank is 58,830 acre feet and 3,500 farmer families are benefited from the tank.

The Usgala Siyambalangamuwa tank constructed by King Mahasen (274-304 AD) is in dire need of extensive renovations.

The tank has not been repaired after it was reconstructed by the Department of Irrigation in 1955.

Due to a major water seepage in the dam it is considered as a high risk dam. This tank is one of the downstream tanks in a cascading system and as a result water released or spilled water by several upstream reservoirs come to Usgala Siyambalangamuwa tank.

The spill of the tank was blasted to reduce the risk during heavy rain last year as water levels increased sharply. As a result over 3,000 acre feet (out of 21,600 acre feet capacity) of the tank is idling. The cultivated area under the tank is around 2100 hectares. Renovation work is being carried out by the State Development and Construction Corporation. The estimated cost is Rs.157 m.

As the monsoon rain has begun, construction work had to be postponed, Irrigation Engineer A. Rajakaruna said. The progress of work is behind schedule due to bureaucratic bottlenecks.

The DSWRPP launched in 2008 has planned to renovate 32 of the 80 large reservoirs which are considered risky due to dilapidation with aging.

Most of the ancient dams dating from a 2,000 year-old irrigation based civilisation were made of packed earth.

Most of them have not undergone any major repair in the recent past.

Under the DSWRPP, it has identified that these tanks have seepages, cracks in the dams and parts of the dams have even sunk. Spill gates, sluice gates and other safety mechanics too are in a dilapidated condition and need immediate modernisation.

The objective of the DSWRPP is to ensure public safety and address key challenges faced by the water sector in the country.

With the dams getting older it has been found that they suffer from various structural deficiencies.