Revitalizing irrigation tanks Vellathukottai

These tank systems are centuries old built by ancient kings and chieftains now owned by different agencies of the government based on the extent of area irrigated and source of water supply.

They are larger in numbers with wider geographical distribution causing in adequate attention by government agencies. The farmers are also not able to maintain them properly due to poverty and lack of coordination among them.

In such a contingency, there is an imminent need for the community organizations to get actively involved for revitalizing such indigenous marvelous water harvesting structures.

Goals overview

The goals of the project are to rehabilitate all 6 tanks in the Vellathukottai tank cascade system to enhance crop production in the command area of 210 ha serving 340 farmers and benefiting another 420 families indirectly. To ensure sustainability of improvement by transferring the skills to the community. Ensuring nutrition security for the local people through fish rearing. Another goals is improving the micro climate around the water bodies through 20 micro finance groups.

Current status

All the 6 tanks in the Vellathukottai cascade are not functioning properly and affect tank dependent community for their livelihood support.

Heavy siltation and weed infestation in the tank water spread area and supply channels results in poor acquisition and storage of water. Dilapidated tank structural components such as Bund, Sluice and Weir resulting in wastage of acquired water.

Delinking of tanks in the cascade due to other development works and encroachments in link channels. Due to uncertainty of filling of tanks, farmers encounter frequent failure of crops. Due to this risk the farmers hesitate to invest adequately in their farming leading lesser productivity and making them to remain poor.

Project plan

Earthen bunded small water harvesting structures ingeniously formed by native rulers in South India over the past several centuries in natural depressions of land to catch and store surface run off during intensive spells of monsoon rainfall are known as “Rainfed irrigation tanks” / “tanks”. The area irrigated by each tank varies mostly in between 5 ha to 100 ha, with individual holding size of 0.5 ha. They are smaller in size and larger in number in semi-arid regions of low / medium rainfall.

As these tanks are connected in chains as ‘tank cascades’, there is the effect of synergy in water harvesting, the surplus of upper tank collected in lower tank. Facilitates higher irrigation efficiency due to smaller distribution network with gravity flow.
Before Colonial Rule they were owned, maintained and managed by village institutions and now owned by Government.

Poverty stricken rural community especially the farmers depend mainly on the tank systems for their livelihood as they play a vital role in agriculture, village economy, environment, ecology, culture etc., as they have multiple uses such as:
• Irrigation, domestic & cattle use, fish culture, bird sanctuary and ground water recharge.
• Useful for marginal communities during off-season (short term cultivation in tank bed, grazing land for cattle, usufructs of trees etc.,)
• Flood moderation
• Collect & store nutrious silt for using in agricultural lands.

Due to continuous negligence of maintenance, the performance of tank system has become very poor affecting the poor rural community. This is caused by inadequate attention paid by Government due to wider geographical distribution of tanks and poor allocation of funds. Hence there is a strong need for rehabilitating them in order to help the rural poor by identifying the needy tank cascade on priority basis. One such tank cascade identified for rehabilitation is Vellathukottai tank cascade.

The rehabilitation process includes desilting of link channels and the tank beds to be carried out by the people institutions promoted for the purpose duly after enabling them in addition to practicing improved techniques for agricultural production enhancement. This combined approach would reduce the risk of frequent crop failure for want of irrigation at the fag end of the crop season affecting the poor farming community.
The project also envisages a component for fish rearing in the carry over storage of the tank and micro finance activities for the benefit of landless and women.

Traditional tank system existing in South India considered to be one of the still existing man made water harvesting structure proving their efficiency due to their multiple uses like agriculture, fish culture domestic use, cattle needs, recharging ground water, preserving biodiversity flood moderation and keeping favorable micro climate with environmental sustainability etc.

Expected outcomes

• 6 rainfed irrigation tanks & their linked channels restored
• 210 ha agriculture with increased productivity
• 340 tankfed households assured with higher productivity
• Entitlement and equity for fisheries in tanks for villagers
• 420 non land owning households get indirect benefits

Since the project is going to be implemented by the local community through their associations after skill building, the future maintenance and management of the system will be taken over by them and so the sustainability will be ensured. The people are also willing to contribute 10 – 15% of the rehabilitation cost to establish their right and involvement in project activities. In addition to this, the micro finance activities / fisheries activities will keep the vibrancy of the institutions around the tanks leading to continuity in maintenance.