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Water for Rural Development

Although our per capita GDP during the last few years has increased from US$ 899 in the year 2000 to around 1350 in 2006, Sri Lanka continues to be one of the poor countries in the world. The value of the Sri Lanka rupee has decreased substantially during the last decade. In 1995 a US Dollar was equivalent to Rs. 54.00 and at present it is around Rs. 107.00. The total outstanding government debts have continued to increase from Rs 1218 billion in 2000 to around 2,700 billion. Trade deficit too has continued to increase during this period from Rs. 135 . billion to Rs 350 billion.

Developing the rural  sector:

Any attempt to develop the economy of the country needs to take cognizance of the rural sector which constitutes around 80% of the population. The main source of income of nearly 90 % of the rural population is agriculture and animal husbandry. Almost all the food crops such as rice and other cereals, legumes, field crops, fruits, and livestock produced in the country, valued at around Rs. 100 billion, come from the rural sector.

However, poverty is widespread in the rural sector. For example in Anuradhpura district around 50% of the households are below poverty level ie. below a monthly income of Rs.1500/- The main strategy to develop the rural sector is to reduce poverty by implementing an integrated programme to develop the agriculture and livestock sectors. It will bring about numerous social benefits, increase our food security situation, make food cheaper resulting in higher calorie intake and better nutrition level, reduce the expenditure on food, and increase employment opportunities.

Most of those in the rural sector depend on rainfall for generating income. Water is a key limiting factor in food production and other livelihood improvement in the rural sector. RainWater is also vital for the rural population in various domestic activities including drinking, washing etc.; With increase in pressures of population growth, development aspirations, water is increasingly playing a key factor in socio-economic development and it tends to be a limiting factor in rural development.

Water Resources of

Sri Lanka:

In Sri Lanka, rainfall is the primary source of water. The mean annual rainfall is around 1800 mm with areas such as Hambanthota and Mannar receiving about 900 mm and some areas in Ratnapura/Nuwara Eliya District receiving an annual rainfall about 5,000 mm. The total amount of water the country receives in the form of rainwater is around 100 billion cubic meters per year. Out of this amount of water, around 40% runs-off emptying it to the 103 rivers and major reservoirs and the tanks in the country. Around 35% of water thus collected is used for irrigation and generation of hydro-power and the balance i.e about 65% of the run-off escapes to the sea. Thus, nearly 26 billion cubic meters of water is wasted.

Rainwater

harvesting

Rainwater which comes free is the most pure form of water. If collected and stored properly, it can be used for all domestic purposes including drinking. Collection of rainwater is an effective method of reducing the problem of water shortage. This process will not only increase water availability but also would reduce water bills, increases safety factor against damage by flooding and pollution.. and save energy required for water treatment and transportation. This is of considerable importance at a time when energy is becoming scarce and expensive. Local erosion and flooding during heavy rains is lessened as a portion of local rainfall is diverted into collection tanks.

For centuries the world has relied upon rainwater as a source of water for household, landscape, and agricultural uses. Before sophisticated water systems were developed, rainwater was collected (mostly from roofs) and stored in storage tanks. Today, in many parts of the world, including Hawaii and the entire continent of Australia, rainwater is the principal means of supplying household water. In many Caribbean islands where rainwater is the most viable water supply option and, public buildings, homes, and resorts all collect rainwater to supply their needs. In Hong Kong, rainwater is collected from skyscrapers to supply water needs. Elsewhere, countries like Germany, Japan, United States, and Singapore are also adopting rainwater harvesting.

Water for Crop Production:

The earliest agricultural settlements were in the river valleys in the northern and south-eastern plains and the main crop cultivated was paddy under rain-fed conditions. Hence, farmers were unable to cultivate crops during the dry periods, which is about 4-5 months. In some years the rains would fail resulting in crop failures. This situation prompted our ancient kings such as Parakrambahu1 , who ruled the Eastern part of Sri Lanka in 1140 A.D, to build large reservoirs and construct canal systems. Thus, gradually an intricate system of reservoirs and canals developed. A main feature of the civilization in ancient Sri Lanka was the development of an irrigation technology. Thousands of small irrigation tanks of varying sizes and shapes, particularly in the Dry Zone, provided water for domestic activities and also for crop production. However, at present most of the tanks have got silted and people living in the dry zone have to face immense problems in obtaining adequate water for normal domestic activities and also crop production. Crops in these districts fail causing considerable loss to the farmers and seriously affecting food security in the country.

About 60% of the rain ie. around 60 billion c.m tend to run off finally ending in the sea. Hence, collecting rainwater is extremely important from the point of view of crop production. Cultivation of crops with direct rain (rain-fed cropping) is common in many parts of the country. In the Dry Zone rain fed cropping is practiced mainly during Maha season. These farmers are at a risk, as if rain fails their crops will be affected. In the last few years, in the Dry Zone, agrowells have been constructed under numerous tanks. These are used to lift irrigate high value cash crops during the off season, which enable farmers to earn higher profits. Agrowells are supplied by ground water which is limited. Hence, extensive use of ground water would result in development of saline soils.

The main source of water for irrigation in most of the dry zone areas is river diversions and reservoirs ( tanks). There are around 12,000 small tanks distributed across the undulating landscape in the dry zone. These tanks are not randomly located but occur in the form of distinct cascades each made up of 4-10 small tanks situated with in a single small catchments (meso-catchment) varying in extent from 100-1000 ha, and impound surface relief water of a watershed for irrigation and domestic purposes. These small tanks are concentrated in the dry zone. In the past, these tanks were an integral part of the eco-system and played a dominant role in the socio-economic and cultural aspects of the village leading to a prosperous rural sector by providing irrigation to cultivated large extents of land. However, cultivable extent from these small tanks have decreased gradually with siltation . Due to low rainfall during Yala season there is hardly any water in these tanks and hence cannot supply any appreciable amount of irrigation water during this season.

Effective use of water : Lack of a regular and dependable water supply to increase the area and intensity of cultivation is a major limiting factor in our attempts to develop the rural sector. From the total rainfall, a considerable amount of rain water is lost in the form of surface run-off and conserving this water will promote crop growth in areas where water is limiting. The most effective and economical method of conserving this water is storing it in surface tanks which are abundant in the Dry Zone. However, most of the small tanks are dilapidated and/or silted and needs rehabilitation.

If the run-off water is stored in the land itself, it would be available to plants when there is water shortage. In some parts of the dry zone, small ponds called "Pathahas" have been used to collect and store rain water. Such a water collecting system on farm would enable farmers to cultivate crops during the dry seasons. It also tends to increase the ground water level, thereby making plant growth possible even during the dry season.

As indicated elsewhere, a considerable portion of the rainwater runs-off, which tends to erode soils resulting in degradation of the land. Appropriate soil/water conservation measures such as contour drains/bunds, to retain this water in the land itself would reduce land degradation and promote crop production.

Water Quality

Water quality is closely linked to water use and to the state of economic development and has been heavily influenced by industrial and agricultural chemicals. Water supply to the rural sector is getting increasingly complicated as water contamination escalates, and awareness grows among water users of the links between upstream polluters of water with downstream water users. Microbial contamination of surface water cause serious health problems. Fertilizers run-off into nearby water causing an increase in nutrient levels resulting in a process called eutrophication. This can be a problem in aquatic habitats such as lakes, tanks etc. as it can cause algal blooms. This bloom of algae disrupts normal ecosystem functioning and causes many problems. The algae may use up all the oxygen in the water, leaving none for other aquatic resulting in the death of many aquatic organisms such as fish, which need the oxygen in the water to live. The bloom of algae may also block sunlight from photosynthetic plants under the water surface. Some algae even produce toxins that are harmful to higher forms of life. Agrochemicals and pesticides also pollute water. The renal problems among many people in some parts of the North central Province is considered to be due to these pollutants. There are reports where factory effluents have polluted water in some rivers and other water bodies causing immense problems to inhabitants in the respective areas.

Awareness and education are the two most important ways to prevent water pollution.  If these measures are not taken and water pollution continues, the problem of water scarcity will aggravate.

Integrated Water management

There is a need for a broadened approach to water use as populations grow in regions where water is limiting. Water waste in crop production need to be looked into with implementing appropriate measures to reduce such wastes. Although a crop of paddy needs only 4-5 acre feet of water, farmers in some paddy growing areas use as much 6-7 acre feet of water. In such areas, it is essential that farmer education programmes are conducted to reduce water consumption.

Projected increases in water withdrawal may cause the ecosystem to collapse. Similar problems exist with land degradation. An appreciable extent of agricultural lands are degraded, and drought and desertification threaten the livelihoods of people inhabiting these areas. Further, the low attention paid to water pollution abatement together with the projected increases in water withdrawal and use will exacerbate the water pollution problem.

It is extremely important to realize that the water requirements will involve a continuously growing competition for this resource, and the deterioration of water quality has to be actively abated. A new perspective on water resource management for rural development with the involvement of the rural community adds new dimensions to an Integrated Water Resources Management.

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