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 23 of 167. it t..! ,I I I I~ :. I I J I I I l I I (,,~1~l"Y .& Partners ?~y Ltd. H1l4/l-MRS Nov 26, 1983 Z4<5f ' I)~ No runoff records are currently available for the natu:al cat( hments of the proposed mine~ However, nearby caccl'ments have been studied by the V artment of Transport and y- rks (Refer ..... nce 1) for the purposes of domestic water surp] / to the Pine Creek township. The Department of Transpor~ a~d ~-Ij'orks developed a simple runoff model for the ::1earby Copperfield Creek catchment. The model related monthly ~unoff (in nun over the catchment) to the monthly rain~all using the relationship shown in Figure 5. The form of the rell't_ionship illustrated in Figure 5 i-iaS based on stream flow reco.:rds over the period October 1972 to November 1976. This model yields a percentage of mean annual runoff to mean annual rainfall of 16.4% which compares well with olhe~ nearby catchrn .. nts . The Departwent of Transport and Works' model has been used to simulated natural ru!)off for t,i'lis work. Yearly runoffs for the existing rainfall data have been simulated. As the wet period extends from September to Aprilr yeariy r 'ords have been assumed to extend from September of one calendar year to August of the following calendar year. The simulated runoff records have been ranked and plotted and the median, 1 in 5 year I 1 in 10 year and 1 in 50 year 10"1/'; events have been identified. Figure 6 ShOl,oiS the simulated. runoff probability distribution a...'"1d identifies the year"s records selected as !'epresentati ve for various probabi li ty levels. The rainfall patterns for these years are presented iT! Table 4. RAINFALL PATTERNS FOR SELECTED YEARS R.".INFALL (mm) 11. Hed ian 1 in 5 year 1 in 10 year , in 50 year L 1971/1972 HONTll 1932/1933 1931/1932 1899/1900 September 8.9 0 50.5 10.2 October :7.0 37.3 6.6 14.5 November 199.9 73.2 72.9 39.9 December 210.1 27B.4 10B.7 151. 9 T'1nuary 250.7 194.1 169.2 117.1 February 32B.2 147.6 165.6 ]64.8 t1arch 229.6 269.7 179.1 110.5 April 71. 9 0 3.8 39.1 Hay 0 11. 2 5.1 12.4 June 0 5.1 88.9 4.8 July 0 0 0 22.1, August 0 0 0 0 TOTAL 1376.3 1016.6 850.4 687.6 .\ke:;;e; .~