GroundwaterRecharge,FlowandInter-AquiferLeakage

NAISCommunityCommi@eeWednesday10thFebruary2016

Overview

•  aquifertypes•  rechargeandgroundwaterflow•  drawdownbypumpingbores•  inter-aquiferleakage•  boreconstrucLon•  transportofinjectedrecycledwater

TwomaintypesofAquifers

DiffuseflowPreferenLalorbypassflow

e.g.macropores,fractures,karst

POROUSMEDIAe.g.,sandstone

DUAL-POROSITYMEDIAe.g.,fracturedshaleorkarstlimestone

Groundwater Recharge

Groundwater Recharge

•  Recharge may be defined as # “the entry of water into the saturated zone at the water table”

•  Diffuse recharge: –  widespread percolation through the soil zone

•  Localised recharge: –  focused due to water source or geology –  streams – within bank and overbank flooding –  karst features (e.g., sink holes etc.)

# Freeze and Cherry (1979)

RechargeisonlyasmallfracLonofRainfall

Leaney et al. (2011)

GroundwaterintheHydrologicCycle

GroundwaterFlowSystems

GroundwaterFlowSystems

GoyderInsLtuteProject:AssessmentofAdelaidePlainsGroundwaterResources

Groundwatermovesveryslowly!

Carbon-14acLvityofgroundwatersamples(GoyderInsLtuteProject:AssessmentofAdelaidePlainsGroundwaterResources)

DrawdownaroundPumpingBores

Inter-aquiferLeakage

GroundwaterManagementObjecLves

•  Long-termresourceavailability•  MaintaininggroundwaterthroughflowtopreventsalinisaLon“hotspots”

•  Maintaininggroundwaterthroughflowtopreventseawaterintrusion

•  Maintainingaquiferpressuretopreventinter-aquiferleakageofwater/salts

•  MARisoneopLonthatmayhelpachievetheseobjecLves

WaterBoreConstrucLon

•  MandatoryRequirement•  GoodIndustryPrac5ce

MinimumRequirementsforWaterBores

Unconfinedaquiferbore Confinedaquiferbore=injec5onbore

InjecLngRecycledWater

PredicLngmovementofthefreshwater“bubble”

•  Environmentaland/orappliedtracers

•  Solutetransportmodelling

•  Monitoring

InjecLonWell

AquifercharacterisaLonforMAR•  Keyknowledgerequired:

– AquiferphysicalproperLes(K,T,S)– AquifersalinitycharacterisLcs&chemicalproperLes

(mineralogy,groundwaterchemistry,redoxetc.)•  Proventechniques:

– Aquiferpumpingtests– Aquifercoreanalysis– Groundwatersamplingandanalysis–  Fieldandlaboratorytrials

•  CriLcaltoestablishreliablemonitoringsystemsandmanageoperaLonsasrequired

QuesLons?

ContactDetailsDr.GlennHarringtonDirector&PrincipalHydrogeologistInnovaLveGroundwaterSoluLonsPtyLtd.Office:2/162HindmarshRoad,VictorHarborSA5211Email:glenn@innovaLvegroundwater.com.auPhone:0458636988