According to legends, the origin of the planet earth is based on water. The evolution of living things and the destruction or the extinction had been water centric so often as witnessed by the ancient and present civilisations. The main aim of competitive space explorations is to find whether there is any evidence of availability of water in planetary systems to ensure the possibility of any life in them.
Water is not an unlimited resource. Even though 70 percent of the planet earth is considered as the water globe, only three percent is fresh water. Two- thirds of fresh water is too unavailable for the use of humans due to having been trapped in glaciers or otherwise. Only one percent of the fresh water available for the use of the mankind is shared for drinking, agricultural, industrial and all other needs.
Of the world’s population of seven billion, about 1.1 billion have no access to safe drinking water. Rural communities mainly those under the poverty line are facing difficulties in accessing to drinking water facilities globally. Eight out of ten people in rural areas in Asia and Africa are without easy access to potable water sources, although the United Nations Organisation has accepted that sanitation and drinking water is a basic human right.
Top priority
The Governments or the rulers are expected to give top priority to supply safe drinking water to the people. A population of 2.7 billion is suffering from acute scarcity of water in the world. Since nearly 2.1 billion of the world population is facing hardships in securing potable water, there is a tendency for them to easily falling prey to cholera, typhoid fever, kidney diseases and other contaminated water-borne diseases. In terms of a recent World Health Organization report, about 3.4 million people die in each year due to water-borne ailments mainly the children.
Nature has endowed us with 103 major rivers. Using these rivers, our ancestors, mastered in hydraulic engineering, built over 30,000 major, medium and minor irrigational tanks in the country, mainly in the dry zone. Of the 103 rivers, 27 rivers including Mahaweli, Kalu, Kelani, Ma, Deduru, Kala, Malwathu, Gin and Nilwala have been identified as heavily damaged water sources due to destructive human activities, such as mechanised sand, clay and gem mining, among other irresponsible acts.
Environmental engineers said that it is not impossible for a river with biodiversity to withstand a certain extent of biological waste and flow down without getting polluted, but the quality of water gets deteriorated due to massive bulks of impurities including chemicals added to the water and the riverine environment. The degradation of the riverine environment results in environmental, social and economic problems to humans.
The United Nations Organization has named March 22 as the world water day to make the public aware of the value of the water resources.
Environment protection programs
The Government in response to the growing demand for safe drinking water and simultaneously to counteract destructive human activities which lead to the contamination and pollution of water sources has launched mega environment protection programs such as Surakimu Ganga and Wari Saubhagya for saving the rivers and tank system from further degradation, at a cost of Rs. 32 billion and Rs. 12.5 billion.
Of the rehabilitation of 5,000 rural tanks under the first phase of the Wari Saubhagya program launched in February, 1,500 tanks and anicuts have been renovated at a cost of Rs. 3,000 million. In Sri Lanka, nature has gifted abundant water resources, but people don’t receive food, air, shelter and above all safe drinking water as they wish. Under the Vistas of Prosperity policy document of the Government, the National Water Supply and Drainage Board plans to supply potable drinking water to all by 2025.
The Government has focused on using water in major rivers in the lines of famous saying of great King Parakramabahu, ‘’Not even a little water that comes from the rain shall flow in to the ocean without being made useful to the mankind’’. The following is the water discharge pattern of several rivers.
The Irrigation Department has launched water balance studies in eleven major rivers funded by the world Bank, including Mahaweli, Malwathu , Peduru, Ma, Kelani, Kalu, Nilwala, Gin rivers. The water balance study includes preparation of water sharing mechanisms for future drinking water extractions and identifying water management options including new water resources with proposed catchment management measures for the river basins to meet further water demands in the basin areas.
With the increase in demand for drinking water, especially in the river basins in the dry zone, further improvements are required in the irrigation water usage as well as in the operation of systems to meet the increasing demand for water.
Water allocation in a river basin is firstly to meet the drinking water requirement followed by ecological irrigation and other demands. Even though not established as a legal requirement, the importance of meeting drinking water as a priority has now been established among the major water uses in a river basin.
According to Water Supply Minister Vasudeva Nanayakkara, the demand for bottled drinking water would no longer be a routine requirement by 2025. People would be exempted from trekking long distances in search of safe drinking water.
He said that the Rain Water Harvesting Forum agreed to assist people by encouraging them to practise rain water harvesting at home and to use the water for other purposes.
The Minister said people waste purified drinking water for watering flower plants and washing vehicles. He said that the people should be educated to take to the practice of re-using water.
The National Water supply and Drainage Board (NWSDB) is responsible for the provision of safe drinking water to the people. The NWSDB operates 324 water supply schemes which cover 34 percent of the population with pipe borne water. Some 10.5 percent of the population is served with the pipe borne water supply by local authorities, NGO’s and community-based agencies. Around 13 percent of the population is catered with hand pump tube wells.
In terms of the impact from uncontrolled human activities in reservoirs and major tanks, the Anuradhapura district stands in the forefront especially those providing drinking water to a around 400,000 people. Anuradhapura known as the kingdom of tanks is blessed with major water tanks since the time of ancient kings which were used mainly for meeting the water requirements of the people, wildlife and fish. Other benefits are flood control, the recharge of ground water deposits and recreational activities.
Water quality
The Nuwarawewa, Tissawewa, Thuruwila and Rajangane reservoirs in Anuradhapura are used to extract raw water which is treated before being distributed among consumers.
Water quality data of selected tanks in Anuradhapura was analysed by the Water Safety Plan Advisory unit of the NWSDB to determine the trend of water quality degradation as part of water safety plan implementation. The analysis has revealed that the E-coli count of raw water in Tissawewa has increased significantly than in other tanks.
The contamination level of E-coli bacteria has been on the increase since 2013. The reason for higher values of E-coli can be attributed to the intensive human activities related to the tank water. The water safety plan advisory authorities have recommended to restrict human activities in tanks used to extract water for water treatment plants. A comprehensive catchment management plan should be introduced to ensure water quality in drinking water reservoirs. Alkalinity, turbidity, iron and nitrate concentrations in Nachchaduwa, Rajangane, Angamuwa, Huruluwewa, Manankattiya, Padaviya, Wahalkada, Mahakanadarawa, Tissawewa, Nuwarawewa, Mahawilachchiya have been found greater than the permissible levels following laboratory tests.
According to the Irrigation Department, the damage to rivers is a result of the improper human activities in the riverine environment including river bed, river banks, and river reservations as well as the river basin.
Silting up of waterways could be minimised through activities such as preventing planting shrubs with small root systems in the upper watershed and planting trees with spread out firm standing root systems on areas with steep slopes, constructing dikes to minimise soil erosion and cultivating along contour lines.
According to soil and agriculture experts, more water could be saved for human use through methodologies such as halting deforestation, encouraging reforestation, preserving the forest cover in upper catchment areas of reservoirs and by removing accumulated sediment in reservoir bottoms.
In Anuradhapura, there are new mega water supply projects such as JICA funded phase one and two and Thambuttegama water project. The Yan Oya reservoir, Mahakanadarawa and the Angamuwa tanks are the main water sources for them. Some 400,000 people in Medawachchiya, Rambewa, Padaviya, Kebithigollewa, Horowpothana, Kahatagasdigiliya, Thambittegama, Thalawa and Galnewa will benefit from water projects implemented at a cost of Rs. 76,000 million by 2024.
catchment areas
According to NWSDB (NC) Assistant General Manager Eng. S.C.Ratnayake, Anuradhapura needs 72,170 cubic metres of water per day whereas Polonnaruwa needs 47,150 cubic metres per day. Anuradhapura has 104,614 water connections (40 percent) and Polonnaruwa has 51,200 connections.
Prime Minister Mahinda Rajapaksa recently directed Water Supply and Drainage Ministry officials to take steps to conserve catchment areas in parallel with projects to provide drinking water. The Prime Minister has instructed the Ministry to formulate a joint program with the Environment Ministry to conserve catchment areas.