PRA RESULTS

We present the following findings drawing inference from the five PRA well maps (Map 1 : Year of drilling wells; Map 2 : Distance with other wells and numbering of wells; Map 3 : Yield of wells in thousand gallons per hour; Map 4: Depth of wells; Map 5 : Location of wells by local diviners and geologists).

Once the wells were located on a map, the following picture emerged over a period of several hours (spread over 2 days)

Table 1 : Well Information

Table 2 : Open (dug) well information

Dug wells have been in existence for several decades, and used for irrigation. The average depth of dug wells is 40 ft. The practice of drilling in dug wells began in the 1970s. The last inwell bore was done in 1987. Inwell boring was begun in search of higher volumes of groundwater. All dug wells have been abandoned for irrigation purposes due to insufficient water. The average life of a dug well was ascertained to be 11 years, and that of dug-cum-borewells 8 years. Farmers switched from dug wells to dug-cum-borewells after 11 years of using dugwells; they used the dug-cum-borewells for a further period of 8 years before finally abandoning the wells. Since the 1980s the use of local, labour intensive water lifting devices such as Kapile, Yetha and Persian wheel have been given up since they can only lift water from shallow depths of dugwells. A majority of the dugwells are now being used as groundwater storages.

Table 3 : Borewell Information

The first borewell was drilled in 1972 and is functioning without problems to this date (1994). This point was located by a geologist, and is 400 metres away from its nearest neighboring borewell. It was drilled to a depth of 120 ft., while water was struck at 80 ft., itself, and yields 9000 gallons per hour (GPH). Presently, the average depth of borewells is 207 ft., and the average depth at which water is struck is 117 ft.

The race for borewells could be well understood by considering the case of a farmer who drilled 11 borewells of which only 3 are functioning; the remaining suffered initial failure. The average yield of borewells which worked initially but failed later was 1750 GPH. The Central Groundwater Board, Government of India, have drilled an observation borewell and an exploratory borewell very close to the village.

The local water diviners provided locations for 60% of the wells and the remaining 40% were located by geologists. Of the currently working borewells, water diviners showed 50% of the points and geologists showed the remaining 50%.

The average distance between all types of wells is 462 ft., which is well below the recommended threshold isolation distance. This, coupled with the fact that all dugwells, dug-cum-borewells, and 17% of the borewells have failed after a period of time, provides good evidence to believe the presence of interactive effects in wells.

The above findings provide us insights regarding the degree of well failure and interactive effects among irrigation wells. A better understanding of interference is made possible by adopting the PRA approach to map several other features that impinge on well failure. In order to understand well failure and the equity implications thereof, PRA mapping of the following features is helpful in analysing what different categories of farmers do when there is well failure, what their economic losses are, and how they cope with the situation : 

- Land holding size of well owning farmers.
- Type and present status of well.
- Seasonal variations in depth of water and yield of the well.
- Type and capacity of pumpset.
- Year of well establishment, well failure, and inter-well distance.
- Cropping particulars
- Area irrigated by each well.
- Number of wells owned by each farmer.
- Sources of finance for well establishment.
- Proportion of income realised from irrigated, unirrigated, food and non-food crops.
- Coping mechanisms adopted by farmers to endure well interference.

Conclusions

It was not within the scope of this preliminary exercise to study coping mechanisms and address equity issues. The PRA mapping exercise has provided us guidelines for locating farmers who are suffering from well interference, as a first step towards looking at equity questions and developing a strategy for extension education, water management, credit support, and related aspects that can combine economic development with resource conservation and management. (For example, we found that in adherence to NABARD Guidelines the banks are not extending credit to farmers for well drilling in many parts of Kolar District since the area is considered to have over-exploited its groundwater potential. The farmers have overcome this situation by simply turning to private sources of finance for well drilling. This does not solve the problem of over-exploitation; on the other hand the better-off farmers drill several wells while the poorer farmers cannot  even drill one well since they are not seen to be credit-worthy by the private lending sources.)

This PRA exercise also indicated that there is a race from farmers towards drilling more and more borewells even though the proportion of failure is around 50%. The farmers expressed difficulty in appreciating that dugwells and dug-cum-borewells can also fail because of interactive effects of these wells o  each other. They did not perceive that dug wells and dug-cum-borewells could interfere with one another; they did, however, we perceive that borewells do interfere with dug wells and dug-cum-borewells.

The well interference in a hydro-geological phenomenon prevalent in all the agro-climatic zones of Karnataka. Since these zones have a great degree of variance, the study on interference would suffer from limitation if generalisation of results is attempted by studying areas where groundwater exploitation is intense. In order to obtain a realistic estimate of the intensity of well interference problems in different taluks of Karnataka, the data on the taluk-wise utilisable groundwater for irrigation (from the Central Groundwater Board, Government of India, Bangalore) and number of irrigation pump sets for the year 1992-93 (from the Karnataka Electricity Board) were obtained. Then the ratio (Number of IP sets : Million cubic meter of utilisable groundwater for irrigation) was computed for each of the 175 taluks. The taluks were then sorted in descending order of magnitude of the ratio. The taluks were later classified according to agroclimatic zones of the State in order to obtain the variability in groundwater use across crop types, soil types and climatic types. The agroclimatic zones chosen were North Eastern transition zones, Northern transition zone, Northern dry zone, Central dry zone, Eastern dry zone and Southern dry zone. The North Eastern Dry Zone, Southern transition zone, Hilly zone and coastal zone were not considered as they had favourable situation regarding groundwater interference. The taluk with the highest number of IP sets per MCM of utilisable groundwater for irrigation in each of the six selected zones was chosen for the study.

At a state level meeting with geologists, irrigation specialists, remote sensing specialists, Statisticians, Land Bank  officers and irrigation specialists, the taluks chosen using statistical method were confirmed to be facing the well interference problem relative to other taluks. For the selection of villages within the selected taluk, the village-wise availability of groundwater for irrigation was computed by using the ratio [(net sown area for the village)/(net sown area for the taluk) x (utilisable groundwater for irrigation of the taluk)]. The data on net sown area for the village and the taluk pertain to 1986-87. The village-wise number of wells (for 1986-87) per MCM of utilisable groundwater for the village was then computed. The villages were later ranked in the descending order of the number of wells per MCM of utilisable groundwater for irrigation. For the purpose of choosing the sample farmers, four villages with a high number of wells per MCM of groundwater were chosen, During this choice, villages with any kind of surface irrigation facility (from major, medium or minor irrigation sources) were excluded and only the top four villages which do not have any sort of surface irrigation facility were considered in order to confirm, whether the villages so chosen do reflect the problems of well interference, the research team visited each of the villages and contacted the farmers to confirm the prevalence of well interference phenomenon.

We provide a likely list of equity and sustainability concerns for groups of farmers/resources.

1. Early comers vs. late comers (in the absence of law of prior appropriation).
2. Late comers vs. early comers (in the presence of law of prior appropriation).
3. Farmers in non-tank command area vs. farmers in tank command area.
4. Farmers located in rural areas vs. farmers located near urban areas.
5. Food crop growing farmers vs. cash crop growing farmers.
6. Drinking water well users vs. irrigation well users.
7. Drinking water well use vs. irrigation well use.
8. Groundwater for agriculture vs. groundwater for industry (region).
9. Farmers in low rainfall vs. farmers in high rainfall areas.
10. Farmers in ‘dark’ area vs. farmers in ‘white’ area.
11. Farmers in ‘dark’ area vs. farmers in ‘grey’ area.
12. Farmers in ‘grey’ area vs. farmers in ‘white’ area.
13. Farmers in area with good electricity supply vs. farmers in area with poor electricity supply.
14. Farmers located in areas with dense wells vs. farms located in areas with
sparse wells.
15. Farmers whose wells are interfered vs. farmers whose wells are not interfered.
16. Farmers with dug wells(s) vs. farmers with bore well(s).
17. Farmers with dug-cum-bore well(s) vs. farmers with borewells.
18. Farmers with shallow borewells(s) vs. farmers with deep borewell(s).
19. Farmers with one (poor yielding) well vs. farmers with many (good yielding) wells.
20. Farmers with many (poor yielding) well vs. farmers with one (good yielding)
wells.
21. Farmers with competitive arrangements vs. farmers with cooperative arrangements.
22. Farmers in Non-riparian areas vs. farmers in riparian areas.
23. Farmers located away from irrigation channels vs. farmers located close to
irrigation channels.
24. Farmers without groundwater storage structures vs. farmers with
groundwater storage structure.
25. Farmers in areas where there are no water markets vs. farmers in areas where there are water markets.
26. Farmers with falling water tables vs. farmers with adequate water tables.
27. Farmers with declining water quality vs. farmers with adequate water
quality.
28. Farmers with good access to electricity vs. farmers with poor access to
electricity.
29. Farmers with centralised regulations vs. farmers with decentralised
regulations in groundwater management.
30. Farmers paying pro rata tariff vs. farmers paying flat tariff.
31. Farmers using diesel power vs. farmers using electrical power forgroundwater extraction.
32. Farmers in the downstream vs. farmers in the up streams.

(1) We are thankful to Sri V.Jagannathan, Senior Hydrologist, Central Groundwater Board, Southern Region, Jayanagar, Bangalore for developing this index.

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