Alice Springs town basin, review 2003
Read, R. E.
E-Publications; E-Books; PublicationNT; Report ; no. 42/2003
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Department of Infrastructure, Planning and Environment
Report ; no. 42/2003
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4000000 6000000 8000000 10000000 12000000 14000000 Total water in saturated zone m3 800 1200 1600 2000 2400 2800 M ea n m g/ L Y = 0 .000170 * X + 198 Number of data points used = 6 R esidual sum of squares = 151723 R egression sum of squares = 1.93594E+006 C oef of determination, R -squared = 0 .927324 R esidual mean square, sigma-hat-sq 'd = 37930.8 Figure 33 Relation between stored volume and mean TDS in basin sediments 6.4.1 Northern Zone There seems to be little evidence of groundwater salinisation in this area. One production bore (RN 6782) has showed increasing salinity, probably because of its location near the saline eastern margin of the basin. Soil salinisation is occurring in the heavily irrigated Ross Park marginal to the aquifer. 6.4.2 Braitling This area lies outside the Town Basin in the valley of the Charles River. The hydrogeology of this area is poorly known. Seventeen bores are recorded as having been drilled in it. Some of these are old and poorly documented. Most bores have been dry, but a few have yielded small supplies from fractured Alice Springs Granite. Salinities range from about 400 mg/L near the Charles River to 4000 mg/L. There is no current extraction and historic extraction in this area would have been small. RN 5714 was formerly licensed for 0.5 ML/year, but this seems to have lapsed. The Quaternary alluvium is generally about 6 m thick, up to a possible maximum of 15 m. It is mostly above water table, or has only thin ephemeral aquifers. Fresh rock is at fairly shallow depth on the eastern side near the Charles River, but to the west the regolith is about 15 m thick. One bore (RN 10780) was monitored on the fringe of the area from 1975 to 1980. This shows the decay of the recharge mound following the summer of 1976, but is too short to show the full range of water levels. There has been no chemical monitoring in the area, and the changes due to urbanisation cannot be quantified. 56