Tungabhadra irrigation project was taken up in 1945 and completed by 1953 at a cost of Rs. 130.76 crores. A Board was constituted in 1953 which was reorganised in 1955 as "Tungabhadra Board", and this board is responsible for distribution of water between the two beneficiary states, Karnataka and Andhra Pradesh as stipulated in Krishna water disputes tribunal award.

The irrigation schemes like TBP, are likely to give rise to a variety of detrimental environmental conditions. Such situation warrants EIA as a post project study with the following objectives -

Effects of the project activities on physical, natural and social environment, since inception.

Analysis of alternatives proposed already to suggest procedure and mitigative actions on the negative environmental affects..

Monitoring activities on future activities and implication thereon.

Activities of women, welfare and social sensitization.

Scope of the Project

M/s IN-RIMT, Hyderabad was entrusted with the task of conducting an "Environmental Impact Assessment" of distributary 36 (D36) of Left Bank Main canal by TIPP II (A INDO-DUTCH Cooperative Project). Having implemented the project in the ayacut already localised, the EIA study was focussed on -

Rise of water table in head and middle reaches and fall in tail end areas;

Deterioration of groundwater quality and increase in dissolved solids in drain waters.

Disparity in water supply between different reaches

Disparities in social conditions leading to economical variations and employment;

Lack of resources for women employment, other than agriculture activity.

The EIA addresses the evaluation of the dimensions of these effects and recommend suitable mitigating actions.

Activities Planned

M/s IN-RIMT conducted a quick random household survey to record the views of the beneficiaries in assessing the level of degradation of environment and identify the depth of disparities in force in distribution of water and utilisation of available natural resources and the farmer needs for future developmental process. The legal frame work, and background data were taken up for a detailed study in D 36 command.

Conclusions

The physical features of the command are -

Length of distributary D 36 is about 39 km

D 36 covers 3 villages with a geographical area of 371.4 sq. km.

D 36 command about 18,000 ha with irrigation

Study area is dominated by black cotton soils (vertisols)

Rainfall average is 702 mm.

Population of the area is 76233 comprising 50.3% males and 49.7% females.

Study area is influenced by canal system and local streams.

Ground water potential is moderate and suitable for irrigation in tailend area whereas the available ground water is not suitable for irrigation in head and middle reaches.

Farmers are adopting two paddy crop system in head and middle reaches. Tailend farmers are not getting sufficient water for irrigation.

Excessive irrigation led to salinisation in head and middle reaches

Inequality in distribution of water led to large disparities in economic growth between the farmers

Inequality in distribution of water led to large disparities in economic growth between the farmers. After a detailed study of the above mentioned physical conditions of the area and the chemical analytical reports of water from different sources, the experts team suggested the following interventions for short and long term perspectives.

Equitable distribution of water to the extent possible.

Reclamation of salt affected areas?

Draining of water-logged areas

Formation of water users Associations

Restructuring of existing distribution system

Protected drinking water to each village and

Generation of employment resources for idle labour

Five "Agricultural Development options" (ADO) were suggested to achieve the above objects. In addition a mitigating plan of action and monitoring plan of future activities also was made available in the EIA for future development. The ADOs are explained as under -

1. ADO-I :This option is identified as existing conditions where the farmers in head and middle reach farmers use excess water, more than their requirement and continue to adopt 2 paddy crop, leaving the tail end farmers to suffer in future.

2.ADO-II: This covers no change in cropping pattern, but the ADOs are implemented in developing a positive improvement in existing conditions of water distribution, environment and economy .

3.ADO-III:Introduction of equitable, reliable, predictable water distribution system and allow the farmers to grow any crop of their choice depending on market conditions.

4.ADO-IV:The head and middle reach farmers continue to grow wet crops with the implementation of ADOs and tail end farmers resort to the exploitation of groundwater for conjunctive use. This case suggests a selective type of crop system to suit the irrigation waters available .

5.ADO-V: A revised cropping pattern and establishment of medium and small scale industries are proposed as listed below:

The cropping patterns suggests paddy, sugarcane, banana, cotton, sunflower and other light crops, a mix of which over a period increases the incomes and economic status.

              In conclusion, the following recommendations are included in the report -

Command area development

Environment checklist should be implemented

Demonstration programmes of alternatives

Periodical monitoring of groundwater quality in tail end areas

Socio-economic conditions of different parameters.

Women welfare programmes

Water user associations

Exploration of groundwater for conjunctive use

Small scale industries and sugar factory establishment

Equitable water distribution through crop-water requirements