Alice Springs town basin, review 2003
Read, R. E.
E-Publications; E-Books; PublicationNT; Report ; no. 42/2003
2003-12-01
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Date:2003-12
English
Department of Infrastructure, Planning and Environment
Alice Springs
Report ; no. 42/2003
application/pdf.
Check within Publication or with content Publisher.
https://hdl.handle.net/10070/229443
https://hdl.handle.net/10070/672980
around the Town Basin is likely to be higher than this. Berrys estimate excludes the substantial areas of the town over weathered bedrock, which may have a larger salt storage. Tickell (1994) quotes salt storage for the southern region of up to 790 kg/m2. Average salt storage could be in the range 10 to 100 kg/m2, that is 200 000 T to 2 000 000 T over 20 km2 of urban area. This salt can be mobilised by heavy irrigation of gardens, and possibly by increased recharge as a result of urbanisation as discussed in 5.7.1.3 5.5 Hydraulic characteristics 5.5.1 Aquifers Table 7 shows summarised test pumping data for the Town Basin. Transmissivities range from 1 500 to 30 m2/d. Little testing has been done in the marginal parts of the basin where transmissivities are lower. In the northern zone transmissivities range from about 50 to 100 m2/d. In the southern zone there is a large area where transmissivities are from 500 to 1 500 m2/d (Figure 26 ). Quinlan and Woolley (1969), p.51, concluded that the representative aquifer parameters were; Hydraulic conductivity 45 m/d (150 ft/day) Transmissivity 450 m2/d (30000 gal/day/ft) Specific yield 0.07 The estimate of transmissivity appears to apply to the central part of the Southern Zone. Berry (1992) calibrated a model with hydraulic conductivity ranging from 1 and 2 in the marginal areas of the basin to 160 m/d. Transmissivity of over 500 m2/d are generally restricted to part of the Southern Zone (Figure 26 ). Berrys (1992) model used S values ranging from 0.003 in the marginal areas of the basin to 0.26 in the more highly permeable sands. The parameters used in the model are shown in Appendix F. The average over the cells with non-zero permeability is about 0.09. For water balance studies in Appendix G a specific yield of 0.07 was applied to the whole basin with satisfactory results. An attempt was made to estimate hydraulic conductivities in the marginal zones of the aquifer (Appendix I). The weathered bedrock was found to have a hydraulic conductivity of up to 6 m/d, but generally less than 1. The adjoining bedrock aquifers have no significant effect on the water balance, but because of high salinity may have an effect on the salt balance. 37