Background
Jaffna District population gets its drinking water from underground reservoirs that are layers of limestone aquifers on underground rock, capable of trapping water that can be pumped out for domestic consumption, agriculture and industry. During wet season rain fed irrigation is used mainly for paddy cultivation. The capacity of the underground reservoirs has remained almost constant while the demand for water has increased over the years. The water resources lack replenishment and situation made worse by uneven distribution of rainfall. In the good old days the ecological balance was well-maintained, where the amount of water drawn during the year was less than that percolating into the reservoirs. In the wet season these aquifers get recharged, while recharge gradually decaying in the dry season.
In the last century with increase in population more water was drawn out, this process was reversed to some extent by increasing the amount of rainwater retained on the surface by building barrages at the entry points of seawater at the lagoons in the peninsula. A river for Jaffna project known as the Arumugam plan was implemented in the ’50s by closing the openings in the road and rail bridges in Elephant Pass causeway at the western end of Jaffna Lagoon to prevent fresh water collected during the wet season going waste to the sea from this end and a bund was built at the eastern end of this lagoon at Chundikulam to isolate it from the sea, with a spillway provided to discharge excess flood water to the sea. Then Jaffna lagoon with most of it surrounded in the east by the Chundikulam sanctuary became a fresh water lagoon. A long channel, called the Mulliyan link channel was constructed from the north eastern side of the Jaffna lagoon to convey fresh water from it to the Vadamarachchi lagoon at its southern end, including regulatory gates to control the flow. Thondamanaru barrage at the northern end of Vadamarachchi lagoon where it joins the sea was built, to make Vadamarachchi lagoon a fresh water lagoon. Windmills were provided to draw water for cultivation. The Arialai barrage was built where the Upparu lagoon connects to the sea, to make Upparu a fresh water lagoon. A link channel was built between Vadamarachchi and Upparu lagoons to supply fresh water from Jaffna lagoon to Upparu lagoon via Vadamarachchi lagoon.
In Valikamam area of the peninsula, the amount of rainwater retained was augmented by Valukai Aru with its chain of surface reservoirs and a barrage was built at Araly where it connects to the sea. Valukai Aru is a dry river that facilitates rain water runoff to the sea in the wet season. The largest surface tank Perriya Kulam or Ponnalai Kulam borders five villages and saltwater exclusion bunds constructed along the southern coast all aid to extend the period of recharge longer into the dry season in the Valikamam. The islands have limited facilities to recharge hence they are less populated than the peninsula itself.
With increase in population coastal barren lands on the peninsula were occupied and cultivated with available brackish underground water. In the second half of last century many drinking water supply schemes were introduced by National Water Supply & Drainage Board (NWSDB) to provide drinking water many of these coastal areas. In addition Jaffna Municipal Council had a water supply scheme installed for the town area. Due to poor maintenance and neglect in the past three decades all these schemes ceased operation. In the same period the river for Jaffna scheme was neglected, the link channel failed to function properly and the bund at Chundikulam breached due to heavy floods, thus allowing sea water to enter into Jaffna Lagoon. Also amount of rainwater retained in the lagoons in the peninsula reduced considerably and got polluted by seawater seeping through the damaged barrages. At the same time the quality of ground water deteriorated due to unrestricted use of insecticides, pesticides and chemical fertilizers. The coastal barren lands were not protected due to breaches in the seawater exclusion bunds. Salinity of water in wells near the coastal areas increased due to large amount of withdrawals which caused the heads to decline and the fresh water salt water interface to rise resulting in salt water intrusions in several areas in the peninsula. The water sample taken during the dry season from random wells in these coastal area were tested in Singapore laboratories for this report showed a conductivity levels of over 4730μS/cm, while the permissible was <750, Total Dissolved Solids (TDS) was in excess of 1890 mg/l with permissible <500 and Total Hardness (as CaCO3) was above 250 mg/l with permissible <100 confirming that the water was not suitable for human consumption.
With the end of hostilities all the water supply schemes, the sea water exclusion barrages at the lagoons and the coastal seawater exclusion bunds in peninsula were all repaired and put back to service by the state. The river for Jaffna scheme has however remained neglected and abandoned to date. With life returning to normal and rise in population increased the water drawn out of the underground reservoirs in the district. But many villages are not yet served by any water supply schemes with people daily having to travel many kilometers to get access to safe drinking water, particularly in the south western coastal areas of the peninsula and the islands.
In this backdrop three years back residents of many villages at the center of the peninsula observed that their well water being contaminated with oil and grease. The wells near the power plant were tested by NWSDB, who analysed around 100 wells in the surrounding areas of the Chunnakam power station, which includes Uduvil and Kopay DS divisions in November 2013. They found around 80% of the wells polluted with waste oil ranging from 0.33 to 19.40 mg/l, when the permissible was <1.0 mg/l and confirmed that the water is polluted with furnace burner oil used by the power plant. The level of oil contamination appeared to be uniform up to 500m from the plant and this appeared decreasing from there up to 2000m. These analyses favor a point source to be located within the power plant area. Unhappily the wells still left unpolluted are unfit for consumption and as a temporary measure local authorities are supplying drinking water to the villagers in bowsers.
The groundwater imbalance in peninsula through overuse and the water pollution caused would reduce the availability of freshwater that would gradually lead to crisis proportions in the future. The authorities have in the recent past considered importing water from mainland and producing water by desalinating sea water, where it was planned to install a desalination plant in Vadamarachchi east was met with stiff opposition from the people, probably politically motivated, but could have prevented it had there been a consultation with the people to study the impact. Also no environmental impact assessments were made by the authorities that require consulting people affected to hear their views. These alternatives increase the cost of water supplies, than addressing the demand side of water management. Furthermore with the current poor water user practices and lack of proper water management from the authorities to control water use and monitor quality of water resource have all contributed to present water problem in the peninsula.
New regulations and conservation practices
The authorities must adopt a long term, economical and sustainable water management practices. A regulatory framework of new regulations and conservation practices is needed to prevent the water crisis. These to be implemented at the earliest to increase water use efficiency, including correct selection of crops and irrigation methods to prevent further loss of quality freshwater. The urgency today is to meet the safe drinking water needs of the population and to achieve it a scientific approach is needed to conserve and limit extraction as a per cent of the annual recharge to prevent a severe imbalance developing in the aquifer.
Monitoring Quantity and Quality Control
Restrictions on the use of mechanical pumps and regular monitoring of the ground water table are measures needed to reverse a worsening situation. The public need to be made aware of the issues in particular the farmers against over extraction as ways to ensure adequate replenishment of the Jaffna aquifer. The industries and others who dispose effluents into the ground are to comply with regulations to prevent the recurrence of manmade disasters as seen at Chunnakam Power Station.
Water Conservation Tax
Supplying water to meet the needs of the people is just one part of the challenge for the authorities. In order to ensure the sustainability of water usage, water conservation is a much required aspect to manage demand for water. It is recommended to introduce a water conservation tax to enable those who conserve water to pay very little or no tax, while those who do not conserve their water usage pay a higher tax. By introducing to end users awareness program to conserve water, monitor and take legal action against industries and others found polluting water resources, increasing the age old practice of rainwater harvesting with modern methods, introducing water treatment plants at intakes and reclaiming of wastewater using modern technologies. These solutions of meeting water needs cost less and have low impact on the environment and move society towards more realistic environmentally sound lifestyles and better water use practices.
Water Treatment Plants
As there is widespread pollution of underground water, it would be necessary to have treatment plants installed at the various water supply schemes as found necessary. In the case of wells at Chunnakam Power Plant NWSDB has to get the tests repeated to select a suitably sized treatment plant and be assigned to operate the water treatment plant, who would initially feed polluted water from wells and continue to do so until the quality of water from these wells are of acceptable levels to WHO standards. At this point the wells shall all be flushed out and washed with clean water. Earlier during the treatment process the pumps draining the wells would not be operated continuously as the wells get depleted after few hours and time must laps for the wells to get recharged. This process will continue till all the polluted wells are all cleared of pollution, flushed and washed. The cleaned water from the treatment plant shall be tested for quality, if acceptable be used as potable water or used for other purposes.
Water purification plant
To meet the safe drinking water demand of the population it would be necessary to install appropriately designed water purification plants for areas where no water supply scheme exists at present. In the areas where no supplies exist, the purified water from the installed water purification plant could be distributed by an authorized provider. The people in the selected area to form consumer groups and each group install a storage tank, which will be filled as required on payment of a nominal sum to the Provider. Pending on its success similar plants will be installed in all areas in the district requiring safe drinking water.
Recycled water
One popular method of conserving freshwater is by use of recycled water. The terms recycled water mean wastewater sent from a home or factories through a pipeline system to a treatment facility, where it is treated to a level consistent with its intended use. The water is then routed directly to a recycled water system for uses such as irrigation or for industrial purposes. Scientifically-proven advances in water technology allow communities to reuse water for many different purposes, including industrial, irrigation, and drinking. The water is treated differently depending upon the source and use of the water and how it gets delivered. Simply stated, reclaimed water is water used more than one time before it passes back into the natural water cycle. Reclaimed water or recycled water is former wastewater (sewage) that is treated to remove solids and impurities, and used in sustainable landscaping irrigation, to recharge groundwater aquifers, to meet commercial and industrial water needs, and for drinking.
Harvesting Rainwater
Rainwater harvesting in the conventional way to recharge the underground reservoirs have been implemented, but need to be maintained properly. There are over thousand surface storage tanks of varying size in the peninsula and the islands, these tanks require proper renovation including regular de-silting and flood water drainage canals leading to them are cleared ahead of wet season to ensure maximum retention of flood water in these tanks. As many of these tanks have been neglected or taken over by unauthorized constructions need to renovate or construct new rainwater reservoir tanks in public places as required to reach the objectives. Rain water harvesting from roof tops using modern methods is recommended for direct consumption at the point of collection. There are this type of rain harvesters in use elsewhere in urban areas of the country, but has not been implemented in a big way in the District.
Artificial charging of underground reservoirs
This process is only possible with proper scientific approach, where surplus run off during wet season is harnessed and feed into reservoirs underground as a process to conserve the runoff rather than allowing it to spill into the sea. This is a new technology, but could be taken up by the authorities with technical assistance from Universities to systematically record and monitor wells over a period around recharge point to evaluate success of recharge.
Importing water from mainland
To meet the water demand of the district a plan was prepared to import water to from the Irranimadu tank in the adjacent Kilinochchi District. Unfortunately, this plan was half baked and cooked up in haste without study of impacts. Failure to realize that water would not be available at the tank during dry season to meet additional demand by this plan and that the tank had to meet the ever increasing water demand of the Kilinochchi district in the dry season and could have only met the demand by this plan in the wet season. Had the plan gone ahead it would have left the peninsula beneficiaries without water in the dry season. Well into construction phase the project met with stiff opposition from the Kilinochchi farmers, may be it was politically motivated caused the project to be abandoned, but as said earlier was not a viable project.
Desalination of seawater
Desalination of seawater is an industrial process that converts seawater or salty groundwater into distilled water. Care needed to avoid contaminating any existing ground or surface water with the salts contained in the byproduct brine. The brine could be dried in the sun to form salts or could be dumped into the sea after thinning it with seawater in a mode to prevent any impact to marine life. Desalination could be considered as the last resort when no other alternatives are available, as it is an expensive process and require lot of energy. Desalination of seawater is already considered to the islands that are far away from the peninsula, to meet the drinking water needs of the islanders.
Reactivation of the River for Jaffna project
Long term and durable solution to avoid future crisis in the peninsula is to reactivae the River for Jaffna plan that would turn Jaffna Lagoon into a fresh water lake. In addition to activating all existing facilities and introducing water conservation measures the River for Jaffna project could be reactivated by sealing off the east end of the Jaffna Lagoon preventing seawater entering and to have facilities let flood water during wet season to spill to the sea and to flush out the salty water present in it. Earlier, due to improper construction and subsequent lack of maintenance the objectives were not fully achieved. Irrigation Engineers must study the causes of failure of the project and prepare improved design estimate for the project. To provide at the eastern end of the lagoon at Chundikulam a proper bund with better spill facilities, to isolate the lagoon from the sea and to discharge excess flood water to the sea for flood relief. Flushing out shall be monitored scientifically, employing science graduates to be employed in this development project. When the water reaches acceptable standard could feed the lagoons in the peninsula as planned earlier via a long link channel at Mulliyan that runs in sandy base, which is badly damaged and silted. This was not well taken care of in the original scheme as the low sloped channel was congested with silt due to neglect and poor maintenance that prevented natural flow. The channel should be reconstructed properly with a mild slope and regularly maintained to convey fresh water from Jaffna Lagoon to the Vadamarachchi lagoon at its southern end, including regulatory gates to control the by gravity flow.
Reclaim land for development projects
The Jaffna Lagoon contour shall be adjusted and the lagoon depth increased and the sod used to fill its periphery to form reclaimed land for future development around the lagoon that would be turned into a freshwater lake. On both sides of this lagoon power generating farms with wind turbine generators and or solar panels could be installed to generate electricity. In the reclaimed land appropriate agriculture activities and in the new lake formed fishing activities could be initiated. Land not suitable for agriculture could be allocated for appropriate food processing industries for marketing and value addition.
CSP for seawater desalination
There are new processes for desalination which are cost effective such as concentrating solar power (CSP) for desalination of seawater, but needs properly trained personnel to operate and maintain the plant. CSP for seawater desalination is very suitable in the Jaffna lagoon project area, which could use the available solar energy to produce drinking water from seawater. A desalination plant appropriately sized shall be installed near the western bund at elephant pass with intake of salty water from this lagoon to produce drinking water to be stored at the water treatment plant at Palai for distribution to Jaffna city. This desalinated water with that produced at present by the existing supply scheme will be sufficient to meet the increased water demand of Jaffna City. The brine concentrate discharged from the CSP desalination plant shall be negotiated and sold to the saltern manufacturing salt at present west of Elephant Pass. At a later when the Jaffna lagoon becomes a freshwater lake, the CSP plant could function as a standby facility to make up any shortage in the supply of fresh water in the dry season taking intake feed from the west side of the elephant pass bund.
Recommendations
River for Jaffna project is to compliment the water conservation program of Jaffna district using the present water supply facilities in place as stated in this report. At a future date when the link canal is built, the lagoons in the peninsula with proper functioning of the barrages could serve as a source of fresh water supply. Water purification plants could then be installed at suitable locations to supply fresh water to Jaffna city and other urban areas in the peninsula. All of which needs a professional approach with due respect to the people in the area and the environment, this was missing in the past which obstructed the development of the region.
A preliminary study needs to be done to consider possible environmental impacts and awareness created among the stakeholders to resolve each impact prior to commencement of the project. The scope of the study must also cover feasibility analysis to convert Jaffna lagoon east of Elephant Pass as a lake for the storage of fresh water over a period of five years utilizing all the four rivers from mainland on the southern part of the lagoon to replenish it; they are the Kanakarayan Aru, Nethali Aru, Paramanthal Aru and Theruvil Aru. By using the fresh water runoff from the rivers in the wet season and flushing out the saltwater in the lagoon to the sea. The project could achieve its objectives before five years, if the plan to feed Kanakarayan Aru basin from a perennial river of other provinces, for then there will be continuous supply of fresh water spilling off from the Irranimadu tank.
Northern Breeze 