impact of river sand mining on the groundwater regime in kerala– an overview p nandakumaran, t. s....

Nandakumaranetal.ImpactofriversandminingongroundwaterregimeinKerala

IMPACTOFRIVERSANDMININGONTHEGROUNDWATERREGIMEINKERALAANOVERVIEW

PNandakumaran,T.S.AnithaShyam,MiniChandran,V.R.Rani,G.Srinath&A.D.AnilChand

CentralGroundWaterBoard,KeralaRegion,Thiruvananthapuram,KeralaEmail:[email protected]

Abstract. Mining of sandisrampantinmanyriversofIndia.Withtheconstructionboomfuellingthe demand,weakgovernanceandwidespreadcorruptionarefacilitatinguncontrolledandillegal miningofsandandgravelintherivers,threateningtheirveryexistence. Thismindless,unrestrainedand unregulatedactivity is posingthreatsof widespreaddepletionof waterresources, especially groundwater, whichmayposeaseriousthreattothewaterandfoodsecurityofthecountryintheyearstocome.Thispaper presentsanoverviewoftheenvironmentalimpactofriversandmininginKerala,withspecialreferencetothe groundwater.Legalprovisionsavailableforpreventionofillegalminingofminormineralsandmeasuresfor minimizingadverseimpactsofriversandmininghavealsobeendescribedinthepaper.

Introduction.

Inthepastfewdecades,thedemandforconstructiongradesandhasincreasedconsiderablyinmanypartsoftheworldduetorapideconomicdevelopmentandsubsequentgrowthofbuildingactivities.This,inmanyoftheoccasions,hasresultedinindiscriminateminingofsandfrominstreamandfloodplainareas,leadingtoseveredamagestotheriverbasinenvironment.SuchimpactshavebeenreportedfromseveralcountriessuchasIndia,SriLanka,Malaysia,Nigeria,Australia and the USA, to site a few. Moreover, lack of adequate information on theenvironmentalimpactofriversandminingisamajorlacunachallengingregulatoryeffortsinmanydevelopingcountries.

SandMininginIndia. Sand is vital for sustenance of rivers. It hasnowbeenestablishedbeyonddoubtthat uncontrolled sandminingfromtheriverbedleadstothedestructionoftheentireriversystem.Ifsandand gravel are extracted in quantitiesexceeding the capacity of the rivers toreplenishthem,theyleadtochangesinits channelform,physicalhabitatsandfoodwebstheriversecosystem.Theremovalofsandfromthe river bed increases the velocity of the flowing water, with the distorted flowregimeeventuallyerodingtheriverbanks.Besidetheseonsiteeffects,theoffsiteeffectsarealsoquitelethal. Sandacts likeasponge,whichhelpsin rechargingthewatertable; itsprogressivedepletionintheriverisaccompaniedbydecliningwatertablesinthenearbyareas,adverselyimpactingpeoplesdailylivesandultimately,theirlivelihood.Riversand,therefore,isvitalforhumanwellbeing.

This,however,isyettobeappreciated,asisseeninseveralstatesofthecountry.Forinstance, inMadhyaPradesh, indiscriminateandrampantminingofsand is takingplace inmajorriverslikeNarmada,Chambal,BetwaandWainganga,aswellasinnumerousrivuletsand streams. Bharathapuzha, the second longest river of Kerala, has become a victim ofindiscriminate sand mining. As the journal India Together reported, 'Despite numerous prohibitionsandregulations,sandminingcontinuesrapidlyontheriverbedoftheBharathapuzha. Watertableshavedroppeddramaticallyandalandonceknownforitsplentifulriceharvestnow facesscarcityofwater.Inthevillagesandtownsaroundtheriver,groundwaterlevelshavefallen drasticallyandwellsarealmostperenniallydry.Palakkad,adistrictlargelydependentontheriver

Shaji E&PradeepkumarAP(Eds)2014 Mineral ResourcesofKerala Trivandrum:DeptofGeologyUnivofKeralaISBN9788192344904106


fordrinkingwater,isexperiencingwatershortagewithincreasingregularity.Withthesandcover gone,shrubsandacaciagroveshavecroppedupinthemiddleoftheriver.Asourceofdrinking waterforabout700,000peoplein175villagesandseveraltowns,Bharathpuzhaisrapidlyceasing to be so. Meetings and rallies are held on its drybed while drinking water becomes a scarce commodity. Infact, reckless sandmininghasreducedthewaterholdingcapacity of several riversinthestate.Theybecometricklessoonafterthemonsoonsonlytodryuplater. Keralamay,inallprobability,loseitsgreenmantleandmaynotbeabletoliveuptoitsepithetof Gods own country' (www.indiatogether.org/2005/jun/envsandmine.htm). Similar accounts ofindiscriminatesandmininganditsenvironmentalimpactsareavailablefromvirtuallyeverypartofthecountry.Manystates,likeGujarat,Karnataka,TamilNadu,AndhraPradesh,Goaetc.arealsovictimsofuncheckedillegalsandminingtheconsequencesofwhichareveryserious.

Statusofstudies

InspiteofthehugequantumofsandbeingremovedfromIndianrivers,veryfewstudiesonsandmininghavebeenconductedinthecountry.Mohan(2000b)foundthatoneofthecausativefactorsforthedeclineofriverdolphinpopulationinKulsiRiver,Assamwasindiscriminatesandextractionandrelateddisturbancesintheriver.SunilKumar(2002)studiedthechangesinecobiologyofbenthiccommunitiesduetosandmininginAchankovilRiverinKerala.Sheeba&Arun(2003)studiedtheeffects of sandminingonaquaticecosystemin Ithikara River inKollamdistrictofKeralaandconcludedconsiderablehabitatlossanddecreasedhumusororganicmatterin the rivers. In another study, Sridhar(2004)reported that sandmining in Coleroon River(tributaryofCauveryRiver),TamilNaducausesseriousenvironmentalproblemsinitslowlandareas.Ronnie(2006)reportedthatillegalsandminingtakingplaceonthebanksof ShimshaRivernearKokkareBellurinBangalore,Karnatakaisaffectingthelifeofavianfaunaofthatregion.Mostofthesestudieshavebeenaimedatunderstandingtheenvironmental,ecologicalandsocioeconomicimpactofsandmining.Chandrakantet.al(2005)studiedtheeffectonsandminingongroundwaterdepletioninKarnatakathroughcollectionoffielddataandcomparisonwith a nonsand bearing area. Rajendra et.al (2008) carried out a detailed study on sandextractionfromagriculturalfieldsaroundBengaluru,Karnataka.

AdetailedstudyonsandminingandrelatedenvironmentalissuesinKeralawascarriedoutbytheCentreforEarthScienceStudies(CESS),Trivandrum,Keralain2003asperdirectionsfromtheHonbleHighCourtandGovernmentofKerala.Thestudy,carriedoutwithriverbasinastheunitwasaimedatformulatingresourceallocationstrategiesthatbalancedevelopmentalinitiativesandenvironmentalconsiderations.Theestimationofsandreplacementwastakenasapercentage of the total suspended load over the year. The Centre for Water resourcesDevelopmentandManagement(CWRDM),Kozhikode,KeralaalsoconductedastudyonsandmininginKeralaandreportedthatriversandtothetuneof118457MTisbeingtransportedoutsidethestate.ReportofCWRDM(2006)onquarryingofriversandfromtheriversflowingwithinKozhikodedistrictalsofocusedonthesandexportfromeachstretchratherthanthesandflowestimationoritsimpactongroundwaterregimeofthearea.

ThereviewofstudiesattemptedaboveindicatesthatmostofthestudiesonsandmininginKeralaarerelatedtoitsenvironmentalimpact.Aspertheinformationavailable,nodetailedstudyontheimpactofsandminingongroundwaterresourceshasbeendoneinKeralaStatesofar.

Impactofriversandmining

Sandis extracteddirectly either fromtheactivechannels or fromfloodplainof rivers. Theformerisknownasinstreamminingandlatterfloodplainminingorterracemining(Kondlf,1994a).Theriversandminingresultsin

Changesinthephysicalcharacteristicsoftheriverbasin,Shaji E&PradeepkumarAP(Eds)2014 Mineral ResourcesofKerala Trivandrum:DeptofGeologyUnivofKeralaISBN9788192344904107


Disturbsthecloselylinkedfloraandfauna

Altersthelocalhydrology,soilstructureaswellasthesocioeconomicconditionofthebasiningeneral.

MajorconsequencesofthesandminingfromriversarefurnishedinTable.1

Table 1. General impact of river sand and gravel mining on various components of riverecosystem

S.No System/Components Impactofsandmining

1 Riverchannel Erosionofriverbank,riverbankslumping,loweringofriverchannel

2 Surfacewater Riseinsuspendedparticulatelevel,turbidity,andotherpollutantsfromoil,greaseetc

3 Groundwater Lowering of Groundwater table in areas adjacent to mining sites,damaging the freshwater aquifer system in areas close to the rivermouthzone.

4 Floraandfauna Dwindling of flora and faunadiversity within river basin, decline interrestrialinsects.

5 Culture Damage to the culturally significant places and places of annualreligiouscongregations

6 Coast/Nearshore Lackofreplenishmentofcoastalbeachesleadingtocoastalerosionandreduction in the supply of nutrient elements from the terrestrialsource

(Sources:UNEP,1990,Kondlf,1994b&Padmalal,2002)

Sandminingfromrivershaveanumberofnegativeandveryfewpositiveconsequences.Thenegative impact of river sandminingcanbebroadlydivided intotwocategories: i) Offsiteimpactsandii)Onsiteimpacts.Theoffsiteimpactsareprimarilytransportrelatedwhereastheonsiteimpactsaregenerallychannelrelated.Onsiteimpactshavefurtherbeenclassifiedintoexcavationimpactandwatersupplyimpact.Excavationimpactincludeschannelbedlowering,migrationof excavatedpits, undermining of structures, bankcollapse, caving, bankerosion,channel widening and channel instability. Impact of sand mining on water supply causesreduced recharge to local aquifer, reduction in storage of water for people and livestockespecially during drought season, contamination of water by oil, gasoline etc and Conflictsbetweenminersandlocalcommunities(CESS,2003).Studieshaverevealedthatdepletionofsandinthestreambedsandalongcoastalareasmayresultindeepeningofriversandestuaries, andenlargementofrivermouthsandcoastalinlets.It mayalsoresult inincreasedthreatofseawateringressintothecoastalaquifers. Thepositiveimpactofsandminingincludereductioninfloodsduetodeepeningandwideningofchannelsandprovisionof livelihoodstoalargenumberofpeople,eitherdirectlyorindirectly.

Impactofsandminingongroundwater. Unregulatedandprolongedminingofsandsfromriversmayimpactthegroundwaterregimeinthefollowingways:

i) Loweringofgroundwatertableinthefloodplainarea:Miningmaycauseloweringofriverbedlevelaswellasriverwaterlevel,resultinginloweringofgroundwatertableduetoexcessiveextractionanddrainingoutofgroundwaterfromtheadjacentareas.Thismaycauseshortageofwaterforthevegetationandhumansettlementsinthevicinity.

ii) Depletionof groundwater resource: excessive pumpingout of groundwater duringsand mining especially in abandoned channels generally result in depletion ofgroundwaterresourcescausingseverescarcityandaffectingirrigationandpotablewater



availability.Inextremecasesitmayalsoresultincreationofgroundfissuresandlandsubsidenceinadjacentareas.

iii) Groundwatercontamination:Incasetheriverisrechargingthegroundwater,excessivemining will reduce the thickness of the natural filter materials (sediments) throughwhichthegroundwaterisrecharged.Thepollutantsduetomining,suchaswashingofminingmaterials,wastesdisposal,dieselandvehicularoillubricantsandotherhumanactivitiesmaypollutethegroundwater.

iv) Chokingoffiltermaterialsforingressofgroundwaterfromriver:Dumpingoffinalmaterial,compactionoffilterzoneduetomovementheavymachineryandvehiclesforminingpurposesmayreducethepermeabilityandporosityofthefiltermaterialthroughwhichthegroundwaterisrecharging,thusresultinginsteadydecreaseofgroundwaterresources.

ImpactofsandminingongroundwaterregimeinKerala

AsperstudiescarriedoutbyCentreforWaterResourcesDevelopment&Management(1999),thetotalquantityofsandusedinKeralaisoftheorderofabout4milliontruckloads,whichisroughlyequivalenttoabout32millionMT.Accordingtoscientificstudies,about4,67,000cu.mofsandisremovedfromtheriverbedsannually,againstaveragereplenishmentofabout15,000cu.m.Theunscientific miningof sandfar exceedingthenatural replacement has reportedlydeepenedtheriverbedsbyasmuchassixmetersduringthelasttwodecades.Theloweringof riverbedshasalsobeenobservedintherivergaugingstationsofCentralWaterCommission(CWC)invariousriverbasins.

InspiteoftherampantandindiscriminateminingofsandfromalmostallriversintheState, no detailed information on its impact on the groundwater regime is available. Sandmining is known to deepen the river beds, which will adversely affect the recharge ofgroundwaterneartherivercourseandintheadjoiningfloodplains.Thiswillultimatelyresultinthereversalofhydraulicgradient,inducingincreasedflowofgroundwaterfromtheaquiferintotheriver,causingdeepeningofwaterlevels,dryingupofshallowwellsandreductioninthesustainability of groundwater abstractionstructures. Varioussandminingactivities mayalsoresultinthecontaminationoftheriverwaterandthegroundwaterinhydraulicconnectionwithit.Themagnitudeofdepletionofgroundwaterresourcesneartherivercourseswilldependonvariousfactorssuchasthetopography,slope,thicknessofsandintheriverbedandfloodplain,widthoftheriverbed,natureoftheriver(effluent/influent) etc.Inareaswhereastreamiseffluent,continuedsandminingandloweringofriverbedwillresultinsteepergradientsofgroundwaterflowfromtheaquifersandacceleratedseepageofgroundwaterintothestream.Inthecaseofaninfluentstream,progressivedeepeningoftheriverduetosandminingwillresultinthereductionofgroundwaterrechargefromthestream,ultimatelyleadingtodryingupofshallowwells.

Asalreadymentioned,theaveragequantityofsandusedinKeralaperyearisabout32MillionMT(CWRDM,1999).TheprimaryuseofsandintheStateisformakingreinforcedconcrete for construction of infrastructure. As per available statistics, average annualconsumptionof cement in thestate during200508wasof theorder of 7.125MillionMT.Assumingthatthisentirequantumofcementwasusedformakingconcreteatthecementsandratioof1:3,thetotalrequirementofsandinvolumetrictermsworksoutas14.25Millioncu.m. (Assumingabulkdensityof1.5Tonne/Cu.m).Thevariationinthefiguresarrivedatbythetwomethodsprobablyindicatethatsandbeingminedfromtheriversarebeingusedpurposesotherthanconstructionofbuildings,suchasfillingupofwetlands,paddyfieldsetc..However,asperstudies04),theaveragequantumofsandminedfromtheriverbedsofthestatesannuallyisof the order of 0.40 Million cu.m only. The disparity between various estimates, althoughapproximate,pointstothepossibilityofa)largescaleimportofsandfromtheadjoiningstates



and/orb)illegalsandminingfromrivers,streamsandfloodplainswhicharenotaccountedforintheofficialestimates.

Themagnitudeoflossofgroundwaterstoragespaceduetoriversandminingcanbeenvisagedwhenweconsiderthefactthatremovalofeverycubicmeterofsandfromtheriverbedresultsinthelossofapproximately0.5cu.mofaquiferstoragespace(assumingaporosityof50%),which,inanundisturbedcondition,remainssaturatedalmostthroughouttheyear.Hence,theminingofsuchhugequantitiesofsandresultsinthelossofalargequantumofgroundwaterstorageintheriverbeditself,inadditiontootheradverseimpacts.

Legalprovisionsforpreventionofillegalmining

TheMinesandMinerals(DevelopmentandRegulation)Act,1957, enactedbytheIndianParliamentdeclaresitasanActtoprovideforthedevelopmentandregulationofminesandminerals under the control of the Union. It relates to regulation of minor mineral ordevelopmentofminormineralsandisintendedonlyasameasureofregulatingtheupkeepandmaintenanceofnaturalresourcesofthecountry.

TheKeralaProtectionofRiverBanksandRegulationofMiningofSandAct,2001,undersection13(2)oftheConstitution,empowerstheDistrictCollectortonotifythebanonsandremoval fromany river or river bank during any period, if dredging of sand disturbs thebiophysical environment system of the river. The Sand Act is intended to address theindiscriminateanduncontrolledremovalofsandfromtheriverswiththeprimaryobjectofpreventinglargescalelossofsandfromriverbanksandriverbedsleadingtolossofwater.IntheSandAct,thereisalsoprovisiontoconfiscatevehicleswhichisintendedasameasuretodiscourageindiscriminateremovalofsand. ThoughseveralpowersweregiventoauthoritiesundertheAct,certainerrorsintheprovisionsofSandActaffectedKerala'sSandMiningLaws.On23rdFebruary2010,theKeralaHighCourtorderedquashingofallcasesundertheSandAct,2001resultingintheneedforbroaderandproperamendmentofSandAct(2001).SeveraldecisionsrenderedbytheIndianSupremeCourtandvariousHighCourtsexplainclearlytheactivistroleplayedbyJudiciaryincombatingenvironmentalproblems.

InAttakoyaThangalv.UnionofIndia(1990KLT580),theKeralaHighCourtheldthattherighttosweetwaterandtherighttofreeairareattributesoftherighttolife,forthesearethe basicelementswhichsustainlifeitself.Righttolifenotonlymeansanimalexistence.Ithasmany facetsandcleanandreasonablesupplyofwaterisoneofthem.

InKinkriDeviv.StateofHimachalPradesh(AIR1988HP.4),theHimachalPradeshHighcourtheldthatNaturalresourceshavegottobetappedforthepurposeofsocialdevelopmentbut tappinghastobedonewithcaresothatecologyandenvironmentmaynotbeaffectedinany seriousway.Thenaturalresourcesarepermanentassetsofmankindandarenotintendedtobe exhausted in one generation. The Honble Court issued interim direction to the StateGovernmenttosetupacommitteetomonitortheuncontrolledquarryingoflimestoneintheState.

InRuralLitigationandEntitlementKendra,Dehradunv.StateofUttarPradesh(AIR1985SC652),theSupremeCourtorderedtheclosureoflimestonequarriesonthegroundthattheiroperationswereupsettingecologicalbalance.

InSubhashKumarv.StateofBihar(AIR1991SC420),theSupremeCourtheldthatpublicinterestlitigationismaintainableforensuringenjoymentofpollutionfreewaterandairwhichisIncludedintherighttolifeunderArticle21oftheConstitution.Itfurtherheldthatifanythingendangersorimpairsthequalityoflifeinviolationoflaws,aCitizenhasrighttohave recoursetoArticle32oftheConstitutionforremovingthepollutionofwaterorairwhichmaybe detrimentaltothequalityoflife.



InM.C.Mehtav.UnionofIndiaandothers(AIR1996SC1977),theSupremeCourtdirectedthattheminingoperationsinBallabgarhareaofFaridabadbestoppedwithin2Kmradiusof thetouristresorts.Itfurtherdirectedthatminingleaseswithintheareaof2Kmto5Kmradius shouldnot berenewedwithout obtainingprior NoObjectionCertificate fromtheHaryanaPollutionControlBoardandCentralPollutionControlBoard.TheCourtnotedwithconcernthatexcessiveminingmayalsocausefracturesandcracksinthesubsurfacerocklayercausingdisturbancetotheaquifers whichare thesourceof groundwaterandthismaydisturb thehydrologyofthearea.

In VelloreCitizensWelfareForumv.UnionofIndiaandothers(AIR1996SC2115),theSupremeCourthasgivenitsapprovalto"SustainableDevelopment",whichstrikesabalancebetweeneconomicdevelopmentononehandandwelfareofthepeopleontheother.Itstatedthatthetraditionalconceptofdevelopmentandecologybeingopposedtoeachotherisnolongeracceptable.ItfurtherheldthatSustainableDevelopmentisabalancingconceptbetweenecologyanddevelopment and "ThePrecautionary Principle' andThePolluter Pays" are theessentialfeaturesof"SustainableDevelopment".

In IndianCouncil forEnvirolegalActionv. Unionof India(AIR1996SCW1069), theSupremeCourtheldthattheabsoluteliabilityforharmtotheenvironmentextendsnotonlyto compensatethevictimsofpollutionbutalsothecostofrestoringtheenvironmentaldegradation RemediationofthedamagedenvironmentispartoftheprocessofSustainableDevelopmentand suchpolluterisliabletopaythecosttotheindividualsuffersaswellasthecostofreversingthe damagedecology.

InManimalayarSamrakshanaSamithiv.StateofKeralaandothers(WP(C)No.31125of2006),theKeralaHighCourtheldthatillegalsandminingisbeingcarriedoutbythesand mininglobbyintherivers of Kerala, especiallyManimala, Pamba etc. TheRiverManagement Committeesarenotfunctioningproperlyinspiteofthelegislationpassedandtheexpertcommittee isnotcontinuouslymonitoringtheeffectsoftheminingofsandfromtherivers.Beforeconducting auctionineachyear,expertcommitteeisnotmeetingorvisitingtheplace.Thisisasorrystateof affairs.TheGovernmentshouldseethatcollectionofsandwithinonekmofanyofthebridgesor anyof the irrigationprojects intherivers of Kerala is prohibited. Beforeauctioningthesand mining,reportfromtheexpertcommitteeshouldbeobtainedandwithoutobtainingafavourable report, no steps for auctioningsand should be done. Thecourt further directed the districtadministrationincludingthepolicetopreventillegalsandminingbymakingpublicawarenessandalsotocheckillegalsandminingbykeepingaconstantvigil.

In Subramanianv.StateofKeralaandothers(2008),theKeralaHighCourtheldthatthechallenge against the competence of the State Legislature to enact the Sand Act and thechallengetotheconstitutionalityoftheprovisionsoftheSandActareliabletoberepelled.Itfurther gave several directions to the District Collector while passing orders for release ofvehicleseizedwhichareusedforunauthorizedtransportationofriversand.

InSomanv.Geologist(2004(3)KLT577),TheKeralaHighCourtreiteratedthattheprincipleofSustainabledevelopmentandthedoctrinesof"PrecautionaryPrinciple"and"PollutePaysPrinciple''arepartofourenvironmentallawwhichisbuiltaroundArticle21oftheconstitutionofIndia.Itfurtherheldthattheconditionsandrestrictionsimposedinthequarryingpermit wereverymuchnecessarytoprotectourenvironment.

InGokulDasv.Geologistandothers(2009(3)KHC821),theKeralaHighCourtheldthattheloweringofwatertableinmanypartsoftheKeralaStateisofgreatconcernforeverybody.It hasbeenprovedbyscientificstudiesthatthewatertableinthestateisgoingdown,whichwould ultimatelyresultinscarcityofwaterintheStateinthelongrun.Theloweringofwatertableisone ofthedeleteriouseffectsofexcessivesandmining.Excessivesandminingwouldresultinmany



other ecological imbalances. It further held that while granting permits for mining sand in propertiesnearrivers,evenifthepropertyisbeyondthedistancelimitprescribedintheKerala ProtectionofRiverBanksandRegulationofRemovalofSandAd,2001,thereisareallikelihood dangerofunscrupulouspersonsmisusingthepermittocauseirreversibledamagetotheriverbeds. TheDistrictCollectorhasasayinthematterofissueofminingpermits.TheDistrictCollectoris competentandempoweredtoconsiderthequestionastowhetherminingofsandfromaparticular property would cause damage to ecology. He can certainly issue orders regarding banning of miningofsandinparticularareasinadistrictorinthedistrictasawhole.Thesourceofsuch power can be traced to Article 21 of the Constitution of India, even if such powers are not specificallyconferredbytheRules,forensuringSustainableDevelopment. Thecourtalsogavedirections for the formation of Expert committees to regulate mining of ordinary sand inspecifiedareas.

Governmentinitiativestocurbillegalsandmining

Inviewofthelargescaleenvironmentalimpactofillegalanduncontrolledminingincludingsandmining in thecountry, theGovernment of India hasdirectedall state governments toconstitutehighlevelcommitteestocrackdownonillegalminingandintensifythedriveagainstthemenace.Thesecommittees,inlinewithasimilarpanelattheCentre,wouldprepareactionplanstopreventillegalmining.Sofar,onlyninestatesAndhraPradesh,Chhattisgarh,Gujarat,Goa,Karnataka,Maharashtra,Orissa,RajasthanandWestBengalhaveconstitutedcommitteestoaddressissuessuchasillegalminingandfasterprocessingofmineralconcessions.Thestatesweretoldthatthecommitteesshouldbeheadedbyeitherchiefsecretariesoradditionalchiefsecretaries.

At present, there are not enough legal provisions for Central intervention in illegalminingacrossthestates,whilethemagnitudeoftheproblemissogreatthatasmanyas42,000casesweredetectedin11mineralbearingstateslastyear.TheCentrehasaskedthestatestoreportallinstancesofillegalminingandusesatelliteimagerytodetectsuchactivities.Ithadalsoaskedforcellstobesetuptomonitorpricetrends,asaspurtinpricesisusuallylinkedto increasedillegalminingactivities.Stateshavealsobeenaskedtotrackthemovementofvehiclescarrying minerals, andusebar codes andhologramson transport permits. Other directionsinclude the collection of information from ports, customs authorities and the Ministry ofCommerceonexportoforesandcompulsoryregistrationofallenduserstocheckpaymentofroyaltybeforepurchaseofores.Thestategovernmentshavealsobeenaskedtofinalisemineral concessionsfaster.Meanwhile,aprovisionthathasbeenaddedtothenewmininglegislationstatesthatanyonefoundguiltyofillegalminingwillbedebarredfromdoingitanywhereinthecountry.

Geoscientificmeasuresforminimizingadverseimpactofsandmining

Somegeoscientificconsiderationsforminimisingadverseimpactofriversandminingaregivenbelow:

1. Abandonedstreamchannelsonterraceandinactivefloodplainsmaybepreferredratherthanactivechannelsandtheirdeltasandfloodplains.Replenishmentofgroundwaterhastobeensuredifexcessivepumpingoutofwaterisrequiredduringmining.

2. Streamshouldnotbedivertedtoforminactivechannel,3. Mining below subterranean water level should be avoided as a safeguard against

environmentalcontaminationandoverexploitationofresources,4. Largeriversandstreamswhoseperiodicsedimentreplenishmentcapacityarelarger,may

bepreferredthansmallerrivers.



5. Segmentsofbraidedriversystemshouldbeusedpreferablyfallingwithinthelateralmigration area of the river regime that enhances the feasibility of sedimentreplenishment,

6. Miningat the concave side of theriver channel should be avoided to prevent bankerosion.Similarlymeanderingsegmentofarivershouldbeselectedformininginsuchawayastoavoidnatural erodingbanksandtopromoteminingonnaturally building(aggrading)meandercomponents,

7. Scrapingofsedimentbarsabovethewaterflowlevelintheleanperiodmaybepreferredforsustainablemining,

8. Itistobenotedthattheenvironmentalissuesrelatedtominingofmineralsincludingriverbedsandminingshouldclearlystatethesizeofmineleaseholdarea,mineleaseperiod,mineplanandmineclosureplan,alongwithminereclamationandrehabilitationstrategies,depthofminingandperiodofminingoperations,particularlyincaseofriverbedmining.

9. Miningofgravellysandfromtheriverbedshouldberestrictedtoamaximumdepthof3mfromthesurface.Forsurfaceminingoperationsbeyondthisdepthof3m(10feet),it is imperative to adopt quarrying in a systematic bench like disposition, which isgenerallynotfeasibleinriverbedmining.Hence,forsafetyandsustainabilityrestrictionofminingofriverbedmaterialtomaximumdepthof3m.isrecommended,

10. Miningofriverbedmaterialshouldalsotakecognizanceofthelocationoftheactivechannel bank. It shouldbe locatedsufficientlyaway, preferablymorethan3maway(inwards),fromsuchriverbankstominimizeeffectsonriverbankerosionandavoidconsequentchannelmigration,

11. Continuedriverbedmaterialmininginagivensegmentoftheriverwillinduceseasonalscouringandintensifytheerosionactivitywithinthechannel.Thiswillhaveanadverseeffectnotonlywithintheminingareabutalsobothinupstreamanddownstreamoftherivercourse.Hazardouseffectsofsuchscouringandenhancederosionduetoriverbedminingshouldbeevaluatedperiodicallyandavoidedforsustainableminingactivities.

12. Theminedoutpits shouldbebackfilledwhereverwarrantedandtheareashouldbesuitablylandscapedtopreventenvironmentaldegradation.

References

CentreforEarthScienceStudies,2003:RiversandminingfromPalakkaddistrict,Kerala.Thiruvananthapuram,pp.80.CESS,2004a.RiversandminingfromErnakulumdistrict,Kerala,Projectreportofdistrictwiseupdateof

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Chandrakanth, M.G., Hemalatha, A.C., Nagaraj, N., 2005. Effect of sand mining on groundwater depletion inKarnataka. InternationalR&DConferenceoftheCentralBoardof Irrigationandpower, 1518Feb,2005,Bangalore.

CWRDM,1999.SandMininginKeralawithspecialreferencetoPeriyar,CentreforWaterResourceDevelopmentandManagement,Kozhikode,61p.

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Mohan,R.S.L.(2000b)TheBlindriverdolphinsofIndia.http//www.grieb.org/dolphins

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Sridhar.(2004)Cauverydelta:newreality.http://www.indiatogether.org/2004/mar/envgroundh20.htm.

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impact of river sand mining on the groundwater regime in kerala– an overview p nandakumaran, t. s....

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