1 June 2008
Preplanning Measures To Tackle Water Crisis
The huge and soaring subsidies rendered to the irrigation works, flood control and drainage projects causing fiscal crisis to exchequer have pressurized the govt fund allotments to regulate water management, not adequate and not duly released. Generally any organization would allow fund allotments to a project only if it could provide a reasonable rate of financial return. But this criterion can not be applicable to a welfare state. Ignorance and negligible act of water management would lead to irreparable loss and other social problems. It has become a routine feature in Tamilnadu to fight for water. If there is a rain in the summer, no one bother about water issue. South-west monsoon, north-east monsoon, cyclonic depression and local storms contribute to rainfall in different degrees in various regions. Under certain conditions, the cloud moisture condenses and falls back to the earth as rain, hail, sleet or snow, the various forms of precipitation. The rainfall is confined to a few months in a year and maximum flows occur during that period. During the non-rainy months, the river flows dwindle and most of the streams dry up altogether in the state. Well water forms an important source of minor irrigation. Its quality is highly variable due to climatological and hydro-geological conditions. The quality of ground water in many regions shows wide variations with the depth of the aquifers. The depth at which good quality water occurs varies from place to place and even within the same area at a distance of a few metres. In arid area, ground water is very valuable source. Extensive areas in the arid and semi-arid regions have gone out of cultivation due to the depletion of water level. In certain pockets, the ground water is saline and so unusable. The irrigated land of river project is not evenly distributed over the entire region of the state. Rainfall is inadequate and uncertain over large areas. Our water resources are insufficient to meet the long term requirements of agriculture and other uses. The available resource of good surface water is ill-distributed resulting in seasonable abundance and devastating floods in some areas while large tracks in other regions are chronically drought affected. Floods have been damaging large irrigated lands. Sometimes, breaching of tanks leads to the failure of crops. It is estimated that while one-third of our land is subjected to drought, one-eighth of cultivable land is subjected to flood. In permeable soils like sand and sandy loam, losses in earth channels are as high as 20 to 40 per cent of the water delivered in the channels. It is reported more than 76 tmc ft. of water flows into the Bay of Bengal every year in the state. This is because we do not have any major storage reservoir for harnessing the flood water. Earthen channels in many areas are not lined with impervious materials to prevent seepage of water. They are covered with weeds in channels. A large portion of water is lost by seepage for unlined conveyance systems. A properly designed good irrigation structures are essential part of an irrigation system layout. The monsoon floods ravaging the state can be harnessed to meet the acute water scarcity in the state by constructing barrages. The flood water should be impounded by undertaking reclamation of channels and rejuvenation works of ponds. Construction of rural ponds with earthen bund can be provided wherever necessary. Earthen channels require a continuous maintenance works to control moss and weed growth and to repair damage by livestocks, rodents and erosion. Various soil conservation and water harvesting measures should increasingly be undertaken to improve ground water recharge. Methods of sealing saline aquifers should be discussed. If these measures had been undertaken, the Tamilnadu today would be very different from what it is. Many media reports reveal that there is a demonstration of people for extraction of groundwater for city fearing the depletion of water table in their locality. The more we execute these kinds of works, the better it would be for us to sort out water crisis.