This report by Aligarh Muslim University and Central Ground Water Board (CGWB) deals with groundwater flow modelling and aquifer vulnerability assessment in Yamuna–Krishni sub-basin of Muzaffarnagar district. For evaluation of the groundwater resources and for minimizing the error of estimation, the system has been evaluated through aquifer modelling where water balance is established using partial differential equation of groundwater flow and is solved with boundary and initial boundary conditions.
Few blocks of the basin are reported to be over-exploited and some are in semi-critical to critical position. The objectives of the study are –
- Development and improvement of water balance of an aquifer incorporating natural condition of flow system.
- Demarcations of aquifer zone vulnerable to contaminations and feasibility study of its mitigation.
The methodology applied to assess the water balance, uses numerical modeling and vulnerability assessment of the aquifer. Some of the following recommendations and consequences are suggested based on the findings –
- Controlled Abstraction: In order to reduce total abstraction even the present rate of pumping has to be carefully controlled. For example groundwater withdrawal could be reduced in non-command areas where two groundwater troughs have been generated. It is suggested that groundwater withdrawal along river Yamuna flood plains can be slightly increased.
- Augmentation of water resources: Suitable measures for augmentation of groundwater resources may be adopted e.g. artificial recharge may ease the situation in the study area before the situation becomes unmanageable. However, emphasis must be put on demand management as rainwater harvesting will reduce the runoff and further reduce the flow to the rivers.
- Development from deeper aquifer: The groundwater abstraction can be focused on deeper aquifers. The study carried out by CGWB in alluvial parts of Central Ganga Plain have revealed the existence of a huge reserve of groundwater in the deeper aquifer, which have not been fully utilized. The thickness of the alluvium in the area exceeds 500 m and only a small fraction of this is under active circulation due to prevailing shallow groundwater development. Therefore, it is suggested that IInd and IIIrd aquifer should be tapped.
- Development of flood plain: Flood plains in the vicinity of rivers are good repositories of groundwater. A planned management of groundwater in the flood plain aquifers offers an excellent scope of its development to meet the additional requirement of water. The main efforts, in this regard, are needed to make the groundwater available at the place of demand.
- Restoring traditional groundwater structures: In the past, every village in western Uttar Pradesh boasted of having ponds and community tanks which have been a very good source of groundwater recharge, at least locally. Now, it was observed during the field surveys that the ponds and tanks have disappeared due to encroachment by local people. This has retarded the groundwater recharge of shallow aquifer. Thus revival of such structures is recommended.
- Improvement in Canal System: The present canal irrigation system in the study area is untimely and restricted to the vicinity of main canal. The irrigation channels in the down reaches do not receive water from the feeder canals and thus requires proper management policy to ensure the availability of water at the tail ends of canal vis-à-vis irrigation channels.
- Conjunctive use of surface and groundwater: Conjunctive use of surface water and groundwater resources is the optimal method of obtaining maximum possible water development and the same has been tested and proved in the aquifer modelling.
- Protection of groundwater from pollution: It is suggested that the urban landfill, garbage dumps and effluent channels should either have concrete floor or sheets of impervious film be used to prevent leaching of pollutants in the water.