Ancient irrigation system still 'holds water'

Uses maximum local human resources:

By Dhaneshi YATAWARA

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We are a nation inheriting a proud history filled with marvellous creations by our ancestors. On top of all the achievements our ancestors gifted us a magnificent hi-tech irrigation system unique in the world. Even today the engineering capabilities of our forefathers have astonished the foreigners.

Water is one of the most valuable resources a country is gifted with. We Sri Lankans are blessed to have ample fresh water resources and continuous precipitation cycles throughout the year. We have never had prolonged droughts, desert or such extreme dry conditions. Hence, we are gifted with an ever green nature.

We belong to a highly sophisticated hydraulic civilization which continued for thousands of years. This ancient civilization was the main reason for the successful agricultural economy we were once noted for. The ancient settlers, believed to have migrated from the Indian subcontinent, choose the North Central (Rajarata) and the South Eastern (Ruhunu) plains along the river as their niche. Though the land was excellent for agriculture, the difficulty in diverting enough water to their cultivations was the main problem. Hence the magnificent irrigation schemes were born. We were depending on an agriculture-based economy which prospered in our glorious past until the advent of the european colonizers. Our forefathers knew perfectly well as to how to divert a mass flow of water to their cultivated lands through narrow irrigation canals; they knew the most advanced and environment-friendly method of building huge reservoirs even as early as the 6th century B.C.

As a result we owned three main complex irrigation systems, i.e. Malwathu Oya-Kala Oya, Mahaweli-Amban Ganga and Walawe-Kirindi Oya irrigation systems. According to our written history as depicted in the 'Mahawansa,' the oldest is the 'Basawakkulama' (Abhaya Wewa or the tank), built by King Pandukabhaya in 4th century B.C. and in the 3rd century B.C. 'Thisa wewa' in Anuradhapura was built by King Devanampiyathissa and in the same era 'Yodha Kandiya Wewa' near Thissamaharama was believed to be built by King Mahanaga. These are a few of the living monuments of the earliest stages of this technology.

According to historical descriptions building giant-sized reservoirs had been started in the 1st century B.C. during the reign of King Wasabha (67 - 111 B.C.). According to the historical records the king built 11 large reservoirs and two irrigation canals.The magnificent 'Parakrama Samudra' built by the great King Parakramabahu in the twelfth century is astounding.

We are still deeply rooted in our agriculture based economy. The irrigation systems make a substantive contribution to the development of an efficient agriculture sector. Hence the need for mega projects such as the Galoya and Mahaweli irrigation systems is on the increase. Approximately 80% of our population is still concentrated on rural areas where farmers in large numbers engage in agriculture. We are blessed with a very fertile soil and an excellent climate. Undoubtedly, we can become a self sufficient nation if every inch of the land is brought under cultivation.

Realizing the importance of irrigation and water management the present Government, established the Ministry of Irrigation and Water Management in the year 2007 under Minister Chamal Rajapaksa. Its main objective is to improve the efficiency of irrigation and drainage and ensure the optimum utilization of water resources for enhancing agricultural production and the living standards of the farming community of the country.

The Ministry and the implementing agencies have taken up on priority basis the following multi purpose irrigation projects according to a National Irrigation Plan.

Menik Ganga diversion project (Weheragala reservoir)

Deduru Oya reservoir project

Kekiri Obada reservoir project (Kirama Oya)

Rambukkan Oya reservoir project

Heda Oya Reservoir project

Yan Oya reservoir project

Uma Oya reservoir project

Urawa Diversion and Gin-Nilwala diversion project

Veheragala reservoir under Menik Ganga development is almost nearing completion. Kekiroboda in Kirama Oya basin, Deduru oya reservoir and Rambukkan Oya reservoir are in progress.

These large scale projects will have a lasting impact on the development of the regions and the river basins. Their contribution to overall economy is significant.

Rambukkan Oya project.

Uma Oya multi purpose project in progress.

The Weheragala project aims at benefiting a part of the Hambanthota district specially by providing an additional water supply to the Lunugamwehera reservoir built by obstructing the nearby Kirindi Oya. The project will ensure a continuous water supply to the Manik Ganga. Relocating illegal settlers in the Lunugamwehera national park, creating grasslands as fodder for the cattle and reconstructing the roads inside the park as well as protecting the natural reserve will be additional responsibilities coming under the project. The total project costs around 1722 million rupees. The Deduru Oya protect in the Northwestern Province, is expected to cultivate 27,000 acres of paddy. In addition a power plant generating 1.5 mega watts is included under the project. The project is expected to be finalized by 2010.

The Kekiriobada project is implemented in the Walasmulla pradeshiya sabha area in the Hambanthota district crossing the Kekiri Oya - a branch of the Kirama Oya.

The Rambukkan oya reservoir project focuses on benefiting the farmers of the Maha Oya area in the Ampara district. This reservoir is believed to be built by King Sadhdhathissa. The reconstruction started in the year 2007 with a total provision of 2500 million rupees. It is expected to finish by 2010.

The Yan Oya reservoir project benefits the Anuradhapura and Trincomalee districts while the Heda Oya reservoir project caters to the Ampara district.

The Urawa diversion from Nilwala river is to stabilize Nilwala, Kirama Oya, Muruthawela and Chandrika Wewa systems and the Gal Oya Navodaya (revival) is to support the projects under the Eastern revival. The Gal Oya Navodaya proposal in the Ampara district is aimed at opening a new chapter in the Gal Oya valley. The proposed package of projects will address the sector goals, regional and national objectives.

On top of all, is the Uma Oya project, initiated with the assistance of the Iranian Government. It will benefit mainly the Moneragala and Hambanthota districts.

These projects, which benefit large extents of existing lands will also embrace a substantial extent of new lands to be developed. Unregulated flows in these rivers will be stored or diverted to provide the facilities downstream; with other infrastructure in place and assured water supplies.

Projects are identified or conceptualized for irrigation and multipurpose development including hydro power, flood protection and salt water exclusion. Under this, Kelani Ganga basin development including flood mitigation and urban water supply, Ratnapura in Kalu ganga and Kalu-Gin-Nilwala complex with options to divert water to the southestern dry zone is a modified proposal. Preliminaries and feasibility studies are to be completed.

The ministry has launched a comprehensive development program in keeping with 'Mahinda Chinthanaya' in the irrigation and water resource sectors.

Uplift of the rural economy and installation of a firm water-related infrastructure for the growth and expansion of the agricultural sector are the main objectives. It will be according to a national irrigation plan incorporated in the 10 year development frame work. The National Irrigation plan with river basins development strategies is to be adopted according to a master plan and projects and programs are formulated and implemented accordingly. In parallel with the other development activities, an islandwide program for appreciation of the irrigation civilization of Sri Lanka and conservation and protection of the heritage by awareness and betterment of water management is implemented, named 'Nil diyawara - Keth Yayata'. This will contribute to the overall national effort in this sector.

The dry zone and water stressed parts of the island are to be transformed in to fertile agricultural lands. These new projects are implemented in order to harness unutilized water resources, including more storage facilities and trans-basin diversions.

According to the statistics gathered by the Ministry 2005/06 maha season average yield in irrigated areas was 4.66 metric tons per hectare and in the maha season of 2006/07 it increased to 4.95 metric tons per hectare. And during the yala cultivation period the results were the same. Out of the country's total paddy production around 53% of yield came from inter-provincial major irrigation systems. These projects are implemented in such a manner that it uses maximum local human resources. The funds for these projects will benefit the people living in those areas, where the project will be implemented by generating employment opportunities to the rural folk. Regulation of water flow, in important rivers with dams at suitable locations, and transbasin diversions according to regional water balance plan is one important aspect in the multipurpose development objectives.