Alice Springs recreational dam hydrology report project 6
Jackson, D.; Paige, D.
E-Publications; E-Books; PublicationNT; Report no. 12/1979
1979-10-01
Date:1979-10
English
Northern Territory Government
Darwin
Report no. 12/1979
application/pdf
Attribution International 4.0 (CC BY 4.0)
Northern Territory Government
https://creativecommons.org/licenses/by/4.0/
https://hdl.handle.net/10070/228346
https://hdl.handle.net/10070/674275
Technical Report WRD79012 Viewed at 00:02:46 on 18/02/2010 Page 125 of 153. I I I I I I I I I I I I I I I I I I I I 27 5. RESERVOIR ROUTING 5.1 General From preliminary investigations of costing and operation, a draft of IMm 3 /year and a spillway level of 594 metres was chosen. Flood routing then proceeded with the following assumed spillway arrangement: The main or primary spillway is a"pproximately 150 metres downstream of the Old Telegraph Station and is at 594 metres A.H.D The secondary spillway is upstream of the Old Telegraph Station. This spillway has a crest level of 596 metres A.H.D . Another two metres higher than the secondary spillway is the top of the dam wall. The spillways are arranged so that no water will spill over the Western Saddle and thus onto the site of the Old Telegraph Station. Two cases of spillways were investigated and these are shown in Table 12. Table 12 SPILLWAY ARRANG~IENTS Elevation (m A.H.D.) 594 596 598 Case (a) Total Usable Spillway Width ( m) 50 130 200 5.2 Results Case (b) Total Usable Spillway Wid"th (m) 40 120 190 Floods with return periods of 5, 10, 20, 50, 100 and 500 years, and the maximum probable flood were routed through the dam using PuIs' Method (see Wilson (1974)~ For both Cases of spillway arrangment (i.e. Case (a) and Case (bl, Table 12) alternative routes were done with the dam starting full and at a level of 592.7 metres. 592.7 metres is the elevation which us exceeded" 75% of the time for a draft of IMm 3 /year and a spillway level of 594 metres.