Alice Springs town basin, review 2003
Read, R. E.
E-Publications; E-Books; PublicationNT; Report ; no. 42/2003
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Department of Infrastructure, Planning and Environment
Report ; no. 42/2003
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6.2.3 Efficiency of existing production bores In Appendix I it was shown that there is a strong relation between aquifer transmissivity and the parameters that describe drawdown in a bores. Individual bores deviate significantly from this line, and this is assumed to be an indicator of the standard of the bore completion. Table 12 shows PWC bores with; observed drawdowns in pumping test ratio of the above to average drawdown for the transmissivity estimated reduction in drawdown if completion were the best possible for the transmissivity. The latter has been taken to be 0.6 of the average production bores. It can be seen that while improvements may be possible they are marginal and do not justify the construction of a new bore. Table 12 Production bores with possible reduction in drawdown with improved completion RN Name Estimated drawdown from test data at equipped rate Ratio of observed drawdown to estimated drawdown from line of best fit Estimated reduction in drawdown if completion was improved to the best, m RN006782 Alice Pacific Prod. 1.75 1.06 0.76 RN014095 Golf Club Production 0.92 0.56 0 RN014407 For Alice Springs Golf Club 2.00 0.65 0.14 RN014433 Traeger Pk. 1.75 1.64 1.11 RN015760 Traeger Park. 0.57 1.12 0.26 RN015761 Traeger Park School 1.14 1.59 0.71 RN016356 Site No2 A/S Golf Club 9.92 0.84 2.87 6.2.4 Optimum siting of production bores From the above it is clear that production bores should be located in areas of high transmissivity aquifer. The salinity trends in production bores (Section 5.4.8) show that bores sited near the saline eastern edge of the basin are likely to have increasing salinity. Simple modelling should be used to determine the optimum location of production bores in relation to other bores. 6.3 Sustainability (safe yield) 6.3.1 Previous work Forbes (1962) estimated a safe yield of 680 ML/year. This was made up of 545 ML/year pumping from the basin estimated from the graph in Figure 31 , and 130 ML/year outflow through Heavitree Gap. This was based on observations of draft and water level decline for the years 1957 to 1961, a period of drought and is very conservative. Quinlan and Woolley (1969) estimated a safe yield of about 700 ML/year. Quinlan and Woolley (1969) also suggested that the yield of the basin could be maximised by pumping at 90 ML per month for two months after recharge, and then reducing the 52