Groundwater Resources Assessment and Management of the Bankura District, West Bengal
District level groundwater resources assessment and Management for developmental planning
Latitude : 22038’N - 23038’N
Longitude : 86036’E-87046’E
To create a sound data base on
(i) Depth and fluctuation of water table
(ii) Hydraulic characteristics of principal aquifers
(iii) Geometry of the principal aquifers inventory
(v) Blockwise groundwater resources
(vi) Chemical quality of groundwater
To evolve a practicable scheme for increasing the groundwater potential and
overall enhancement of water resources potential of the area.
To formulate a rational groundwater management plan for meeting up the
increasing demand from different sectors of the society.
For stepwise and systematic implementation of the project the whole work had been segmented into the following work items:
(i) Collection of water level data from the hydrograph network stations established
throughout the district.
(ii) Generation of different types of water level maps and statistical analysis of water
(iii) Compilation of geological maps, keeping in views the hydrological characteristics
of the different formations.
(iv) Collection and compilation of lithological logs of drilling points and delineation of
(v) Collection of data on aquifer parameters and carrying out some pump tests in
open dugwells in selected hard rock areas.
(vi) Collection and compilation of data on chemical quality of groundwater.
(vii) Working out the groundwater potential for each block of the district.
(viii) Development of water harvesting plan for the area and recommendation of
model water harvesting structures with engineering details for selected water
(ix) Development of a groundwater management plan using a computerized
groundwater management model.
The project, which was sponsored by the DST under the NRDMS programme, was carried out from April 1990 to May 1993. The study area of 6881 sq km was marked classified into four zones eg. Plateau, plateau fringe, piedmont zones, marginal plain to delta flank from west to east.
Groundwater occurs under unconfined condition in the hard rock areas of the district and the potential aquifers comprise two units viz. a weathered residuum which is 10 to 20 m thick and the underlying fractured hard rock upto a depth of atleast 50 m.
In the laterite and older alluvium, occupying about 30 percent area of the district in Onda, Taldangra, Simlapal, Raipur, parts of Bankura, Bishnupur, Sonamukhi block, groundwater occurs under unconfined condition. In the eastern alluviul areas covering Indus, Kotulpur, Joypur, Patrasayer and parts of Taldangra, Bishnupur and Sonamukhi blocks, groundwater occurs both under unconfined condition in the shallow aquifers and under confined condition in deeper aquifers occurring below a blanket of clay of thickness varying between 9 and 35 m.bgl.
Large diameter dugwell pump test in the western hard rock area revealed that the aquifer was of low potentiality with the permeability and transmissivity varying from 0.1 to 22.18 m/day and 7.40 to 34.08 m3/day. The average inflow rate of groundwater into the well varied between 4.63 and 43.20 m3/day. In the eastern alluvial areas heavy duty tubewells for irrigation were installed within the depth range varying from 87-304 m.bgl and with discharge varying between 94-183 m3/hr.
Groundwater in the upper reaches and flanks was of Ca-HCO3 type while in the lower reaches the groundwater of Ca-Cl type with relatively higher TDS. This finding provided a rough and ready method of predicting groundwater quality at any given place in Bankura district by noting the location of the particular place in the sub-basin.
There is a vast scope for increasing groundwater recharge in the district by construction of various water harvesting structures such as percolating tanks, sub-surface dykes, gully plugging etc. to store the excess run off. These structures would not only help in recharging the groundwater but also reduce soil erosion and increase soil moisture content. The feasibility of water harvesting structures were indicated for three sub-basins viz. Gandheswari, Birkhan and Murajhor.
Groundwater in the upper reaches and flanks were of Ca-HCO3 type while in the lower reaches the groundwater was of Ca-Cl type with relatively higher TDS. This finding provided a rough and ready method of predicting groundwater quality at any given place in Bankura district by noting the location of the particular place in the sub-basin.
Replenishable groundwater potential available for future development in the district was worked out for each block. Critical comparison of the results of the present hydrological studies with those conducted by the CGWB in 1981 indicated that usable groundwater balance in all the blocks of the district has come down appreciably, and in four blocks, over-exploitation was already taking place. In 1981, none of the blocks suffered from overexploitation of groundwater.
Survey of India toposheets, Satellite images, Vertical Electrical Soundings
Borehole log data, Groundwater samples data for chemical analyses, Pump test
data for various locations, depth to water level data and Meteorological data
With increasing demand for groundwater, utilization of the same is to be planned well in advance for the entire Bankura district. Keeping this in mind a model of management information system for groundwater balance study and prediction of the number of groundwater structures feasible was built up using a PC-based system.
Date of Project completion:
Total cost of project:
Center for Study of Man & Environment,
Parivesh Kendra, CK-11, Sector-2, Salt Lake,
Phone- (033) 23210861, 23590781