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RIVER YAMUNA, THE GROUNDWATER IN IT’S FLOOD PLAIN AND DELHI. By Dr. Shashank Shekhar Department of Geology University of Delhi. NCT DELHI . Ever increasing population and urbanization Greater population Resources imbalance
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RIVER YAMUNA, THE GROUNDWATER IN IT’S FLOOD PLAIN AND DELHI. By Dr. Shashank Shekhar Department of Geology University of Delhi
NCT DELHI • Ever increasing population and urbanization • Greater population Resources imbalance • Water the basic life supporting element becoming scarce day by day • Gap in the demand and supply of drinking water to the tune of 150-200 MGD. • Limited availability of potable ground water in Delhi.
Published : Shekhar, Shashank, Raja Ram Purohit and Y B Kaushik. 2009. Groundwater Management in NCT Delhi. In proceedings 5th Asian Regional Conference of Indian National Committee on Irrigation and Drainage (INCID), December 9-11, 2009, Vigyan Bhawan, New Delhi. Paper available on website: http://cgwb.gov.in/documents/papers/INCID.html
Stage of Ground Water Development After: Chatterjee, Rana, B K Gupta, S K Mohiddin, P N Singh, Shashank Shekhar and Rajaram Purohit. 2009. Dynamic groundwater resources of National Capital Territory, Delhi: assessment, development and management Options. Environ Earth Sci J. 59(3): 669-686, DOI 10.1007/s12665-009-0064-y.
Published : Shekhar, Shashank, Raja Ram Purohit and Y B Kaushik. 2009. Groundwater Management in NCT Delhi. In proceedings 5th Asian Regional Conference of Indian National Committee on Irrigation and Drainage (INCID), December 9-11, 2009, Vigyan Bhawan, New Delhi. Paper available on website: http://cgwb.gov.in/documents/papers/INCID.html
Published : Shekhar, Shashank, Raja Ram Purohit and Y B Kaushik. 2009. Groundwater Management in NCT Delhi. In proceedings 5th Asian Regional Conference of Indian National Committee on Irrigation and Drainage (INCID), December 9-11, 2009, Vigyan Bhawan, New Delhi. Paper available on website: http://cgwb.gov.in/documents/papers/INCID.html
POTENTIAL FRESHWATER AREAS FOR LIMITED EXPLOITATION • Active flood plain of river Yamuna and closely adjacent areas. • Hardrock areas of Delhi ridge. • Dismally low potential Chhatarpur basin. • Zone fringing hardrock areas. • Freshwater lenses along Nallas, water bodies etc.
The Yamuna flood plain: Most potential area for groundwater development Source: CGWB
TRANSVERSE SUBSURFACE CROSS SECTION OF THE YAMUNA FLOOD PLAIN TOWARDS BURARI IN PALLA WELL FIELD. Published : Shekhar, Shashank and R K Prasad. 2009. The groundwater in Yamuna flood plain of Delhi (India) and the management options. Hydrogeology J. 17(7): 1557-1560. DOI: DOI 10.1007/s10040-008-0430-y
The Palla Well Field in Yamuna flood plain of Delhi- A Model of Sustainable Groundwater Development and Management. • IT IS THE ONLY AREA OF THE NW DISTRICT IN PARTICULAR AND NCT DELHI IN GENERAL HAVING CONSIDERABLE FRESHWATER THICKNESS IN THE RANGE OF 35 TO MORE THAN 65 METERS. • THE YAMUNA RIVER IN THIS STRETCH OF STUDY AREA HAS NO VISIBLE MAJOR DRAINS JOINING IT AS SUCH IT IS POLLUTION FREE. • THE AREA GENERALLY GETS FLOODED DURING POST MONSOON INUNDATION OF THE RIVER YAMUNA WHERE THERE IS SCOPE FOR NATURAL RECHARGE TO SUBSURFACE AQUIFERS BY SURFACE SPREADING METHODS DURING MONSOON FLOODS. • THE AREA OFFERS UNIQUE OPPORTUNITY OF MASSIVE GROUNDWATER EXTRACTION TO THE TUNE OF DEWATERING DURING PEAK MONSOON PERIOD AND REFILLING THE DEWATERED ZONE BY INDUCED RECHARGE FROM SURFACE SPREADING OF FLOOD WATERS DURING POST MONSOON TIMES.
DEPTH TO GROUNDWATER LEVEL AND GROUND WATER FLOW • THE GENERAL DEPTH TO GROUNDWATER IN THE AREA HAVE BEEN FOUND IN THE RANGE OF 5.0 METERS BELOW GROUND LEVEL • ON REGIONAL SCALE THE GROUND WATER FLOW CONVERGES TOWARDS PALLA SECTOR , CAN BE SEEN FROM MAP IN NEXT SLIDE.
GROUND WATER QUALITY • The heavy metal and arsenic concentration in the randomly selected tubewell ground water samples was found to be within the permissible limit. • The electrical conductivity of the ground water was found in the range of 350 to 650 micro siemens / cm at 25 Degree Centigrade depending on the location and depth of the aquifers tapped . • The pH of the groundwater samples was found in the range of 7-8. • All the other major elements concentration was found within the permissible limit.
After paper published : Rao, S V N, Sudhir Kumar, ShashankShekhar, S K Sinha and S Manju. 2007. Optimal pumping from Skimming Wells from the Yamuna river flood plain in north India. Hydrogeology J. 15(6): 1157-1167, DOI 10.1007/s10040-007-0173-1 • The palla wells are suggested to be operated on guiding philosopy of skimming wells, to restrict upconing of saline waters. • So to have optimal spacing, the operation of the wells is staggered both in space and time. • Nearly 25-30 MGD of water can be drawn safely during both monsoon and non monsoon seasons to meet drinking water standards( salinity less than 1000 mg/litre)
After paper published : Rao, S V N, Sudhir Kumar, Shashank Shekhar, S K Sinha and S Manju. 2007. Optimal pumping from Skimming Wells from the Yamuna river flood plain in north India. Hydrogeology J. 15(6): 1157-1167, DOI 10.1007/s10040-007-0173-1 • Palla well field helps in utilizing the induced flood recharge, which would otherwise join river boundary. • The Palla model of groundwater development can be replicated in other sectors of the Yamuna flood plain and flood plain of other rivers in India. • The hope in polluted stretches of river lies in RBF whereby the contaminants gets removed and schemes like supplementary drain, large STPs etc.
Some suggestions An extract from paper: Shekhar, Shashank and R K Prasad. 2009. The groundwater in Yamuna flood plain of Delhi (India) and the management options. Hydrogeology J. 17(7): 1557-1560, DOI 10.1007/s10040-008-0430-y : “The NCT of Delhi, being the capital of India, could find itself to be in emergency situations where the installations that supply drinking water may be threatened by natural disasters like earthquake, etc., war, or deterioration in quantity/quality of Delhi’s share of the river water coming through the open canal system. In such situations, the drinking water supply system to Delhi may be jeopardized. The fresh groundwater from the Yamuna flood plain can then be pumped and supplied to different affected parts of Delhi by tanker. It may be worthwhile to assess the maximum abstraction of groundwater from the Yamuna flood plain in emergency situations and the amount of diversion of floodwater needed to replenish subsurface aquifers in such cases”.
Concluding Remarks • The fresh groundwater resources in the Yamuna flood plain of Delhi is a strategic resource and must be managed in judicious way like all other strategic natural resources.