Water has no substitute and is considered to be invaluable and an essential resource for the existence of all living creatures including flora and fauna on the planet. It is not an unlimited resource. While 70 percent of the Earth is considered as the water globe, only three percent is fresh water.
Two-thirds of the fresh water is unavailable for human consumption, since it is trapped in glaciers or otherwise. We are able to use only one percent of fresh water out of the total. A significant percentage of it too, is utilised for agricultural and industrial requirements mainly for maintaining food security.
Out of the total population of the world which is around seven billion, about one billion people are suffering due to the lack of safe drinking water. Nearly 2.7 billion peopleare suffering from the shortage of water at least for one month of the year. Since about 2.1 billion out of the world population are facing numerous hardships and difficulties in securing water suitable for consumption, they so often and more easily fall prey to kidney diseases, cholera, typhoid and a range of various other water-borne ailments. The World Health Organization has said that about 3.4 million persons die each year owing to water-borne diseases.Children are the most affected.
Indispensable resource
The importance of water and the preservation of water resources for the existence of life on the planet Earth is frequently reiterated by world organisations such as UNO, WHO and WFP. Even though water is a vital resource indispensable for the existence of life, it is a pity that various human activities are causing irreparable damage to water resources which need the constant attention of society to take precautionary action to save water from being polluted and going scarce.
It seems that irrigation authorities have underestimated or rather neglected the growing level of contamination of water resources such as rivers, tanks, fountains, irrigation canals, tributaries and lakes. Those dealing with water rich schemes use water extravagantly and freely, while the people in water scarce areas are suffering untold hardships apart from falling prey to various water-borne diseases. Water has an enormous value for farmlands, households, food production, culture, education and the integrity of our natural environment. If we overlook any of these values, we are risking the management of this critical resource.
We are a nation enriched with a great history of a hydraulic civilisation. The world wonders as to how our tank cascade systems (Ellanga) protected and purified water, how our ancestors used the irrigation technology for storing, distributing and managing the water resource sans advanced machinery and equipment available today.
The declaration of great king Parakramabahu that, “Not even a drop of water coming down to the Earth from the rain shall flow in to sea without being made useful to the mankind”, highlights the positive mentality, determination and the technological wizardry of our ancestors, who created irrigational marvels.
The irrigation industry indigenous to our country and passed down from generation to generation from the time of ancient kings is visible in the socio-economic fabric and events related to our culture. The irrigation industry is not just a project aimed at agriculture. It is a subject developed through the broad objectives of helping the people to live and preserve the environment. Itis utilised for different purposes such as drinking water, water needed for industries and generating electricity.
King Pandukabaya made the first attempt to contribute to water security by constructing the first tank in the country, a world heritage now, the “Abhaya Wewa”. Our ancestors built a large number of tanks to preserve water received through rain so that it could be utilised for the benefit of the people without unnecessarily flowing to the ocean. Irrigation networks builtfrom around fifth century BCcontinuing to date, can retain 7,200 million cubic metres of water in 242 major and medium tanks including recently built reservoirs under the Mahaweli Development Authority, while another bulk of water is preserved in the network of minor irrigation tanks, the lifeline of the rural community.
Unwarranted human activities
The problem being confronted today is the protection of water sources for ensuring water security. Large scale deforestation, reforestation progressing in snail pace, encroachment of water source reservations and forest clearing for chena cultivation are causing the destruction and the drying of natural water springs and ground water sources, creating a heavy water scarcity and contamination. These unwarranted human activities have also been the main reason for accumulating sediment in tanks and rivers, which contribute to the contraction of water sources decreasing the water storage capacity.
This situation creates floods even at an average rainfall allowing a large volume of rain water flowing to the sea unutilised. It has become an urgent matter to ascertain the maximum quantity of river water that could be utilised for starting new reservoirs and drinking water projects. The Irrigation Department, however, in consideration of the national level importance of river water management surveillance methodology such as a water balance study, has submitted to the Government authorities to facilitate to hold water balance studies at Kala, Kelani, Attanagalu Gin, Nilwala, Mahaweli, Malwathu, Ma, Deduru, Kalu and Gal Oya basins on a prioritised basis. According to the Riverine Management Unit of the Irrigation Department, there are 103 rivers in the country covering 60,000 square feet water in river basin areas.
Sixteen rivers in the country are more then 100 km long. The amount of water flowing in to the sea through the 103 rivers annually is estimated as 55,000 cubic metres. It has been found in recently held studies and scientific research that water in the majority of the rivers is not as clean as itwasa few decades ago.
As a result, the water flowing in the rivers has had a major impact on human health. Under these circumstances, irrigational experts and environmental scientists demand the authorities to conduct a water balance studying program for gaining updated information about the water usage management and ensure the salvation of water bodies from the grip of unwarranted short sighted human activities.
Water contamination and pollution is caused by poisonous substances and disease causing microbes being added to water from sources such as domestic waste, waste generated as byproducts of industries and the extravagant use of agro chemicals, influencing in a destructive manner on the balance of the ecosystems.
Large scale sedimentation resulting from soil erosion caused by unsystematic cultivation practices and construction on steep slopes, being added to the rivers and other water sources, block sunlight reaching their bottoms creating eutrophication resulting in the proliferation of algae and aquatic weeds hindering the process of clean air mixing with the water. This situation immensely contributes to water pollution.
On the other hand, the ability to store water in the ground water strata through the topsoil has been limited in many metropolitan areas due to concrete layering and interlock paving of open areas. The water security is also threatened since there has been a shortage of water due to the destruction of upper catchment areas of reservoirs, springs and tributaries as a result of large scale deforestation and stoppage of ground water revival.
The construction boom in the 90s has resulted in the mechanised mining of river sand instead of following traditional methodologies for mining sand from sand deposits with the minimum damage to the river. Many river beds have eroded and river banks have collapsed. As a result, the riverine ecological balance has been undermined. For examples, the Ma oyahas degraded due to the clay and sand mining.
Kelani and Kalu rivers are being heavily affected owing to gem and sand mining. The Kelani River has been badly damaged due to human intervention.
The river bed haseroded and up to Hunwella, the river bed is lower than the mean sea level. At a river cross-section survey conducted recently, it was disclosed that the river bed has eroded more than eight metres lower than the mean sea level. During low river flows, saline water intrusion along the river affects the water purification process at the Ambatable water purification plant.
According to the Irrigational Water Resources Planning and Protection unit,there are five processes that shall be followed for maintaining water conservation and sustainable water security, such as to administer the water supply and drainage mechanisms in the most efficient manner, use of ground water in the most appropriate way, not disrupting the ground water strata to replenish, adherence to the proper treatment of waste water, discouraging deforestation, encouraging reforestation, and not allowing water sources to get polluted.
Uncontrolled pollution
The fundamental issue affecting water safety is the uncontrolled water pollution. The water pollution is mainly caused by agrochemicals and fertiliser being washed away in to water sources by rain in high concentrations. In this context, the Government’s decision to take to carbonic agriculture is commendable despite many lapses not digestible to the farmer community.
The silting of water ways could be minimised through activities such as preventing planting shrubs with small roots systems in the upper watershed and planting trees with firm standing root systems in areas with steep slopes.
The Government has embarked on Wari Saubhagya (Irrigation prosperity), Surakimu Ganga andPivithuru Ganga projects for saving the country’s water resources from destruction. If people are continuing stubbornly to pollute water resources, one day, they will realise that they have created their own grave by themselves.
Environment Minister Mahinda Amaraweera referring to the Surakimu Ganga Project said, “It is no secret that water is the basis of nature. Nature can only be saved and protected if the water resources are protected and well looked after. Every time water is polluted, nature is threatened. If people can drink water from any river or natural water source in the country without fear, it is the turning point of the water protection programs including Surakimu Ganga progressing at a cost of Rs. 32 billion.”