Renison Goldfields Consolidated Limited, Pine Creek Project. Groundwater Investigation Stage 2, Establishment of Borefield and Management Studies. Report H114/3-AA.
Coffey & Partners Pty Ltd
E-Publications; E-Books; PublicationNT; Report no. 87/1984
1983-11-01
Date:1983-11
English
Northern Territory Government
Darwin
Report no. 87/1984
application/pdf
Attribution International 4.0 (CC BY 4.0)
Northern Territory Government
https://creativecommons.org/licenses/by/4.0/
https://hdl.handle.net/10070/228435
https://hdl.handle.net/10070/674167
Technical Report WRD84087 Viewed at 14:07:14 on 29/07/2010 Page 58 of 167. I I I I I I I I I I I I I I I I I I I H1l4/l-MRS Nov 26, 1983 (, . 3 At a discharge of 5 lisee, the aquifer can sustain pumping for rer~od tlf 430 days withoilt recharge. Jl.gain these ligures n-cglect any contribut i_on derived from groundwate::::' throughflow, although this is likely to be small. Bilsed on storage alone f the iden.tified areas (AREA 2 arId 3) JPpc<1r to be cap.:.ililc 0: maintaining supply fo:c ?eriods of 'jnly 450 to 550 days! after which time deplr..:ted storage will '-:',:{llse A. reduction i:l bore perfor:wa!l.ce. Such has probably beC't! the case in the Pine Creek bcrefield during per-ioGs of prolong(;d dry. The system there:ore requires periodic rccharqc tu sustain pt.:mping. ltlClt<.'Z' leveL :nonitorinG ~)'i the DTW durinq 1982-83 iic15 show':1 t~';lt wiUlln UtC' town <J.::.-ca, WJt.er levels arc cxt:::-emely r05r~nSlvc La recharge, as illustrated in Figure 17. At ' ':scnt there is insufficiont data with '."hich to quantify !"C't"'horqe it~ anyt.hinq but qeneral tC:::-r:lS, although a :lumber ('1 POHltS 2..rc pr-ob<J.bly :cclev.J.nt. grou:ldw"a tcr !:"ccha. r-qc is t.hougr. t t.o !:Jc assoc i2 tee. '",i th dlrC(~'l infiltratio:l 0:- rainfal:, rather than ::"nCillr0.t.lon dt. :30:11.l.' dJ.st.anc('" fror.l the dquifcr the surface drainage features may facilitate local lnfiltrat.io;l, <1ne conccr:.tr,~tc run-oEf, part 0: wilicn 1:-:> then .J.v<'1ildillc :or direct r0charqe rp)C'ctcd rcchdrge is likely La occur in areas ,tlhere Qioundw<3t.cr 1.5 not extracted by pumping Rejected rech~r'lc occu~s in situations unable to <lCCCpt .udai t.l.o!ldl water into w,J.t<.:r is disch.J.rgcd Vi<l direct runoff. where the aauifc~ is storage. The excess and the groundwZl t-::=r ~ystcm discharqcs via seepage, usually along the drainage 1 fnes. Durinq I1criocis of ~lvcr<J.ge rai:l:o.ll rej-ccted recharge t i',)m t.he- <.1qulfcr is probably .:;onsiderablc. Assessment of rainfall and water level data indicates that 34. cv~>n in a low rai:l:<J.l2. year {say 1 ir. 5 year dry) there has still ~~en sufficient infiltration to induce significant rt;charqc. This is evident ir: the data available :or the 1982-83 wet scason, during \lfhich rain::aIl approached the 1 in. 5 year dry. ~i/iJ.ter levels in a series of town bores still showed recoveries in the order of 4 to 5 metres. In average and above ~vcragc r~l~fQll years it is unlikely the aquifer can accept lIlt-.O storage total potential recha::::::-ge. Such observations scrv~ to illustr~te both the dependency and ~he responsiveness uf the nrounJ.w.o.tcr rcqimc to recharge Clnd suggest that in pt.'riods of If)'_"; r<1inro.ll there may be some scope for artificial rN;hd rgc induced. by simple water reten tion structures.