AN ECONOMIC ANALYSIS OF IRRIGAION TANK DESILTAION IN EASTERN DRY ZONES OF KARNATAKA

R.D. RAMYA

Irrigation tanks are the small reservoirs impounding run off water. Tank irrigation system has been a special significance to the marginal and small farmers. But of late, they have been subjected to gross social negligence causing serious imbalance in hydrological cycle &ecology. With the break down of institutions governing the tank management a vast majority of tanks have been silted, there by reducing storage. These tanks have become economically not viable, socially not acceptable and technically not feasible.

Silt is impounded to tanks by process of sedimentation. Siltation is one of the major problems affecting tank irrigation. The process of removing silt from the tank beds and supply channels is known as desiltation of tanks or rehabilitation of tanks. In eastern dry zone all most all the tanks are heavily silted . This silt can be used to supplement nutrients & improve water-holding capacity of soil.

The major use of silt was fond to be for cropland with 62.08 percent being used as manure. The highest use of tank silt as manure was fond to be for horticultural crops like coconut & grapes & other uses were for strengthening of bunds , rehabilitation of roads, filling open wells &reclamation of lands

The impact of silt application on crop production on some of the locations where in desiltation was done earlier like Cathrakodihally, Mutture, Kasaragatta tanks have indicated beneficial effect on crops in terms of both higher yield and reduced cost on manners &fertilizers (33-50) .According to a study conducted by ORP- Watershed, Hebbal campus, University of agricultural Sciences ,the average crop yield (q/ha) of Ragi was 22 q/ha without tank silt 7 increase to 40.0 q/ha with tank silt ,an increase4 of 82% was reported in Chatrakodihally in 1997. By using partial budgeting, profitability of silt application is evaluated in respect of crop enterprises like ragi &maize ,net benefits due to silt application are realized .

The farmers owing wells indicate there was improvement in water yields in wells, increase in area irrigated, changes in cropping pattern, crop yield &gross return.

Gireesh (1997) conducted an economic analysis on the rehabilitation of irrigation tanks & fond that Incremental net return from crops of tank command area was 2,77,900 (Muttur) 777,125 (Kasaragatta)&internal rate of returns was 14%, the rehabilitation of Muttur tank &29% for Kasaragatta tank for an investment of 196000, based on rehabilitation life of 20 years. The discounted benefits-cost ratio at 10% was 1.13& 1.7 for Muttur & Kasaragatta, respectively. The analysis indicated that investment in tank desilting is economically viable. This indicated that the irrigation potential of tank irrigation can be enhanced to a great extent by desiltation programme.

References

• Arun kumar, Y.S., Ramana gowda, P., Ranganna, B. ,Krishnappa, A. M., (1998) "Impact and Economic of tank Desiltation in Southern Districts with special reference to Kolar" -ORP -Watershed, Hebbal Campus , University of Agricultural Sciences, Bangalore


• Chandrakanth, M.G. and Jeff Romm (1990), Ground water depletion in India: Institutional Management Regimes, Natural Resources. Journal, 30 (3) :485-501


• Dinesh ,K. Marothia (1992) "Village irrigation Tanks ; Institutional Design for Sustainable Resource use " Agricultural situation in India , sep :479-486.


• Gireesh, M. (1996). Rehabilitation of Irrigation tanks in eastern dry zones of Karnataka - An economic analysis's( Agri) Thesis.


• Gireesh, M.,Nagarag,N. &Chandrakanth ,M.G., (1996) .Rehabilitation of irrigation tanks in Eastern zone of Karnataka -An Economic Analysis, Indian Jn. Of Agri. Econ. 52(2); 231-243.