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 151 of 153. I I I I I I I I I I I I I I I I I I I I 48 3.6.2. Discussion Given the localised extent of scour, degradation of the river bed downstream of Wills Terrace is expected to be negligible. Any small bed load deficit will be compensated in large floods by sediment from the Charles River~ Causeways at Schwartz Crescent, Wills Terrace, the Golf Club, the Casino and Ross River Road will further limit the amount of degradation that can occur. Scour will occur at the original Alice Spring at the Old Telegraph Station. However this event occurs only when the secondary spillway is in operation (1 in 6 years on average). If the scour were found to be excessive, a suitable management policy would be to replace scoured material by carting sand from the sediment trap. Some general degradation will occur in the river section between the primary spillway and the confluence with the Charles River. The effects of scour on this section will not be as environmentally critical as the effects at the Old Telegraph Station and downstream of wills Terrace. Scour downstream of the spillway is very dependant on exist velocities from the spillway. In any case downstream scour would be decreased by leaving the alluvial bed of the spillway in place. The spillway itself will scour, thereby decreasing the capacity of the flow for scour downstream. In the event that scour has become serious in this river section after a period of reservoir operation, control structures such as weirs or sheet piling walls can be constructed.