General Description :As per criteria laid down by the Plannng Comission , Govt. Of India; schemes whose Culturable Command Area more than 2000 Ha. are considered as Major Irrigation Schemes and those having CCA less than 2000Ha. are classified as Minor Irrigation Schemes.
WRIDD under Govt. Of west Bengal, mainly deals with the Minor Irrigation Schemes by means of River Lift Irrigation, Ground Water Irrigation etc. Agri Irrigation wing under this department utilise Ground Water Resources, to facilitate small and marginal farmers in areas where irrigation is not covered through Surface Water Resources.
There are different types of installations to extract ground water for serving upto 40 Ha. of command area
Deep Tube Wells/ Heavy Duty Tubewells (DTW/HDTW :These schemes are constructed where water table is more than 7 meters below ground level. Electrically operated Submersible pump sets are used for lifting water to cover the entire CCA through underground pipe lines. These are capable of discharging 200 cubic meter per hour to irrigate CCA of 40 Ha. On availability of vast command area and high yield from the sub-surface strata these schemes are installed.
Medium Duty Tube Wells (MDTW): These are capable of discharging 100 cubic meter per hour to irrigate a CCA of 20 Ha, through underground pipe lines and water is lifted by electrically operated Submersible pump sets.
State Owned Shallow Tubewells (SOSTW): These structures are suitable for areas where water table is less than 7 meters below ground level. Electric operated Centrifugal pump sets are used for lifting water to cover the entire CCA through open channels. Each SOSTW is capable of discharging 30 cubic meter per hour to irrigate CCA of 5-6 Ha.
Above three schemes are owned and operated by this department.
Light Duty Tubewells (LDTW): These are capable of discharging 30 cubic meter per hour to irrigate CCA 5-6 Ha. These structures are installed in a cluster of 5 to 6 tube wells. Electrically operated Submersible pump sets are used for lifting water. These tubewells are handed over to the beneficiaries after installation.
Shallow Tube Wells (STW): These are same as SOSTW, the only difference is that they are also handed over to the beneficiaries after installation
In all these installations it is possible to achieve a cropping intensity of 200% due to availability of water throughout the year.
At present such 50 Nos. DTW/ HDTW/MDTWs and 3 clusters of SOTWs are owned and operated by this office. Their day to day maintenance, repairing, rejuvenation is done under the direct supervision of this office. Distribution of water to the entire command area is ensured by the field staff under the control of this office, in consultation with the beneficiary committee of the respective scheme.
This office also install such type of schemes under different programmes, after obtaining proposals from the direct beneficiaries.
Though some of these structures are handed over to the beneficiaries after installation, but technical expertise for smooth functioning of the same, are always provided by this office.
Special Forms: None