Batchelor water supply development study 1985.
Keith Lane & Associated Pty Ltd
E-Publications; E-Books; PublicationNT; Report ; 68/1985
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Dept. of Mines and Energy
Report ; 68/1985
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Technical Report WRD85068 Viewed at 15:07:30 on 29/07/2010 Page 27 of 58. I I I I I I I I I I I I I I I I I I I I selected because it was approximately midway between the Town's former water supply source (Crater Lake). Advantages of the new site are : (i) The bottom water level in the existing reservoir is 120.9 m, and that in the new reservoir would be approximately 125 m. Some existing service levels in the Town are at approximately 107 m, which results in a pressure head of only 14 m before allowing for any losses. To ensure a pressure head of 18 m at these nodes an elevated tank with a bottom water level of 126.5 m would be required. (iil There site, which track, and the area. is a well-formed track leading up to the facilitates access. Plate E shows the the general environmental conditions of (iii) New distribution mains will be required from the existing reservoir whichever site is adopted for the 3.7 ML reservoir. The length of main from the new site to the existing system is approximately 900 metres, whilst the length of main from the present reservoir site is approximately 1200 metres. (iv) There is adequate room on the site for augmentation, with approximately 0.5 hectares above the 124 m contour. A locality plan with contouring information is given in Figure 4. 10.3.3 Tank Construction: Materials considered for the construction of the tank were fibreg1ass, steel, and concrete. The largest fibreglass tank that can be constructed is 2 ML (approximately 6 m high) and two such tanks would be required. The cost of these tanks would be approximately $400000 (excluding pipework etc.), the advantage being that tanks could be economically constructed as they are required. The construction cost for a steel or concrete tank of the required dimensions would be approximately $380000 (excluding pipework, sitework etc.). A number of water authorities around Australia now prefer steel to concrete tanks because of the slight economic advantages claimed. Steel tanks have easily defined maintenance costs, whilst concrete tanks traditionally have leakage problems which are difficult to quantify and maintenance costs often exceed those of steel. It is therefore recommended that the new tank be constructed from steel. 23