Groundwater Resources Assessment and Management of the Munger District, Bihar
District level groundwater resources assessment and management for developmental planning
Latitude :24023’N - 25030’N
To create a sound database on
(i) Status of water table and water table fluctuation
(ii) Hydraulic characteristics of principal aquifers
(iii) Geometry of the principal aquifer
(iv) Geological sounding to locate water bearing zones
(v) Block-wise groundwater resources
(vi) Chemical quality of groundwater
To evolve a practicable scheme for augmenting groundwater resources by artificial recharge and suitable water harvesting structures.
To formulate a sound plan for development and management of groundwater resources.
For stepwise and systematic implementation of the project the whole work has been segmented into the following work items:
(i) Collection and compilation of season wise water level data available with Central Ground Water Board.
(ii) Collection of water level data from the hydrographic network stations established throughout the district.
(iii) Generation of different types of water level maps and statistical analysis of water level data.
(iv) Compilation of a geological map.
(v) Collection and compilation of lithological logs of boreholes and delineation of aquifer geometry.
(vi) Collection of data on aquifer parameters and carrying out some pump tests in open dugwells.
(vii) Carrying out vertical electrical sounding in order to locate deeper aquifers
(viii) Collection and compilation of data on chemical quality of groundwater.
(ix) Collection and compilation of data on Hot Spring water
(x) Working out the groundwater potential for each block of the district.
(xi) Identification of areas suitable for water harvesting structures.
(xii) Development of a groundwater management plan based on above studies.
The project, which was sponsored by the DST under the NRDMS programme, was carried out from during 1991 to June 1994. The study area of 6398 sq km is characterized by denudational landscapes of hills, plateaus, undulating erosional plains, rocky uplands as well as depositional units such as Quaternary terrace, Ganga plain and Diara plain.Two groups of lineaments (NW-SE and E-W) which traverse all the formations in the area constitute important loci for groundwater occurrence.
It was found that depth to water table varied between 0.73 m and 15.7 m.b.g.l. During pre-monsoon and during post-monsoon, it was between 0.5 and 14.40 m.b.g.l. Polynomial trend surface analysis of water table elevations over the entire district indicated a general northward slope of water table with no major groundwater basins and mounds. Water table fluctuation data showed wide variation between the 1992 and 1993 seasons. A regression study of the block-wise variation of water table fluctuation between 1992 and 1993 indicated major role of rainfall and surface slope on groundwater recharge.
Several perennial hot springs are present along the Kharagpur hill tract. Pump test data of large diameter dugwells in the plateau fringe areas and on the pediplains of Kharagpur hill showed low potentiality of aquifer with low permeability and transmissivity while in the alluvial plains groundwater potential was high with considerable high permeability and transmissivity.
Study of subsurface lithology through borehole litholog and electrical resistivity survey indicated that in the areas of Yonger Alluvium, in general, 3-5 aquifers with varying thickness occurred within an average depth of 85m. Groundwater potential in this area is very good and exploitation is possible to bring the areas under irrigation. In the Older Alluvium areas, covering plateau margin and pediplains, groundwater potential is moderate to low and groundwater exploitation in this area can meet the water requirements for domestic use through shallow tube-wells and open-wells.
Chemically, groundwater in Munger is suitably for drinking and irrigation purposes with rare exceptions in a few places. Groundwater showed dominance of Ca-HCO3 facies in the recharge areas of the plateau grading to Ca-HCO3-Cl2 facies in low-lying regions with local enrichment sulphate.
There is a vast scope for increasing groundwater recharge by construction of various harvesting structures such as percolation tanks, sub-surface dykes, gully plugging etc. to store excess run-off.
The project area covered the districts of Munger, Jamui, Lakhisarai. Hydro geologically, the area is characterized by two domains (a) hard rock and (b) soft rock.
Pre-monsoon and Post-monsoon depth to water level study was conducted in 141 monitoring stations of which at 63 stations are connected by the odolite survey. It was understood that groundwater occurred essentially under unconfined conditions. The study indicated that during pre-monsoon period dept to water level varied between 0.73 and 15.7 m.bgl. and during post-monsoon it was between 0.5 and 14.40m.bgl.
Water table fluctuation was between 0.03 and 3.7-m. Long-term trend analysis of DWTBL indicated both rising and falling trends. Polynomial trend surface analysis of water table contours indicated a northward slope (towards river Ganga) with no major groundwater trough or mound. Results of pump tests indicated low potential with low permeability and transmissivity in hard rock terrain while moderately high to high values were obtained in aquifers of alluvial plains.
Borehole litholog study, supported with electrical resistivity survey, indicated that in Younger Alluvium, in general, 3-5 aquifers with varying thickness occur within an average depth of 85 m.
Ground water potential in this area is very good and can be exploited for irrigation as well as for drinking and other domestic purposes.
Survey of India Toposheet, Satellite images of IRS1B & LISS-II, Bore-hole log data, Vertical electrical soundings (VES)
Groundwater samples data for chemical analyses, Pump-set data for various locations, depth to water level data and Meteorological data (rainfall).
Decadal seasonal rainfall from 1901-90.
Interpreted VES layers (thickness & resistivity) .
Block wise water table status during different seasons.
Geological formation wise water table status during different seasons.
Hydrogeological data of exploratory tube-wells and pump-sets.
Chemical quality of hotsprings and groundwater
Block wise dynamic resource, groundwater balance, feasibility of different groundwater structures.
Suitable sites for different water harvesting structures in different blocks.
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