Responding to Sri Lanka’s water levels in reservoirs fast depleting due to the drought, the government has implemented a short-term programme to rehabilitate minor irrigation tanks and dig 1235 wells in the dry areas. Some State authorities have however charged that these short-term responses lacked information on groundwater tables and consumption patterns for both irrigation and potable water.
The National Water Supply and Drainage Board (NWSDB) noted the lack of a groundwater management system replete with groundwater banks and barriers and desalination plants, the pollution of groundwater and the construction of water treatment plants in natural disaster prone areas were factors which adversely impacted the response to conditions of drought as is prevalent at present.
“A proper plan is required and should have been done at least 10 years back. Policy planners have not taken the issue of this critical factor seriously despite expecting the drought. Planning on the part of top level policymakers with regard to ensuring the provision of drinking water during droughts is extremely poor,” Chief Engineer at the NWSDB Dr. SK Weragoda said.
He highlighted the absence of a national water resources plan or national water policy as a contributing factor.
“Although conducting a proper hydrology research study based on weather modeling is of utmost importance, high level Governmental policymakers had not shown much interest,” he explained.
However, hydrologists opposed a move by the Irrigation Department to build 1,235 agro-wells aside to estimated 25,000 already dug in the dry zone. Senior Lecturer at the Department of Geography of the University of Colombo, Dr. Ranjana UK Piyadasa felt the move was not only unwise but also unethical.
He cited the lack of data on the availability of groundwater and the quality of water as the reasons for taking the said position.
“Digging more wells will exacerbate the situation by increasing the pressure on a resource already under stress due to the absence of rain. These are wide diameter shallow agro-wells that will tap the shallow ground water. They will pump out water every single day,” he said.
Since depleted groundwater aquifer takes time to replenish, vegetation and biodiversity will thus be affected, Dr. Piyadasa further said.
Aside to this, due to the use of agrochemicals being high in the areas, water was quite probably contaminated with high levels of heavy metals such as fluoride (which had also been detected in the areas) that have been hypothesized as causing kidney diseases.
Director General of Irrigation, Engineer SSL Weerasinghe however refuted the claim that the proposed 1,235 agro-wells (12 metres in diameter with a maximum depth of 20 feet) to supply water to paddy fields would adversely affect the groundwater table.
“These are shallow wells and are scattered in a large area. The estimated impact is a one to two foot drop in the groundwater table,” he added.
This is based on the premise that the 1,000 wells dug in 2016 resulted only in a six-inch to one foot drop in the groundwater level.
“These wells are built on requests made by farmers. If and when wells are no longer required they can be closed up. In addition 1000 minor tanks will also be restored. The project is estimated to roughly cost Rs 40 million,” Weerasinghe further noted.
Weerasinghe acknowledged that they did not keep tabs on the many privately owned agro-wells used in areas of vegetable cultivation.
Meanwhile, Chairman of the Water Resources Board (WRB) ACM Zulficar however said that they had been carrying out studies about the groundwater levels and other related areas since 1966 and with the data gathered would be advising the NWSDB on where to extract the water from and how.
“Our only request to the public is to use water sparingly at all times,” Zulficar pleaded.
The WRB has commenced rehabilitating 1242 tube wells which can pump 1000 litres as a counter-measure to address the drought situation and a further 400 new wells are to be constructed by the NWSDB in areas identified as likely to be affected by the drought.