Territory Stories

Floodplain Management Policy, Alice Springs Report by the Alice Springs Floodplain Working Group



Floodplain Management Policy, Alice Springs Report by the Alice Springs Floodplain Working Group


Verhoeven, T. J.


E-Publications; E-Books; PublicationNT; Report ; 37/1983




Made available via the Publications (Legal Deposit) Act 2004 (NT).





Publisher name

Dept. of Transport and Works

Place of publication

Alice Springs


Report ; 37/1983

File type


Copyright owner

Check within Publication or with content Publisher.

Parent handle


Citation address


Page content

Technical Report WRA83037 Viewed at 04:02:48 on 18/02/2010 Page 9 of 14. J J J '1 J 'j ! , ! c I I -' J I -' I .1 , , I: -= " , , -d.::. -, . I ' , !. I , ~ .:.% ,~, r 3.5. 3.5.1. 3.5.2. "< - 3 ...... :) . .. 3.5.4. 3.5.5 . 3.5.6. 3.5.7. . \1 ! I MITIGATION HEASURES The Northern Territory Flood ?la~2 Management Committee's interim policy sta~es inter alia that structu~al works designed to change floodwater behaviour or alter the course of st-reams a:!:"e not encoy.raged.. S'C.ch '.-larks viould include levee banks constructed on the floodplain except in special circw~stances. This indicates that future road crossings of the Todd River should be eit~er bed-level crossings (such as the Ross Highway causeway - with acceptance by the populatio~ noted) or high-level bridge crossings (a large expense for the nuw~er of times required), One mitigation measure which would significantly reduce tr:.e extent 2.~d cos::' of flooding would be a dam constructed on the Todd River at the Telegraph Statio~ Gtilisi~q Spillway Alternative 'A' as de~icted at appendix 'C'. The effect on flooding as a ~esult 0: constructing a dam on the Toed River :.lsir:.g various spillway options has been studied and documented by the Department of Transport and Works and by the Sno' .... y ~lountains Engir,eerir:g Corporation. Spillway Alternative A provides the greatest benefit for flood mitigatior:. The impact of the dam with Spillway 'At canst-ruction would be to reduce the Q100 event to the extent of a Q20 event, Peak discharge is reduced from 1000 cubic metres/second to 620 cubic metres/secor,d. This impact is realised by comparlng appendices 'B' and '0'. The Working Group found that in the opinion of long time residents of the TOW~f the bed of the Todd River is not as lew as it used to be thereby indicating a build up 0= silt. Work undertaken by the Departmen;:: of Transport and Works at various qo~aes in the area also indicate aggrada tion c;: streams. It is estimated that aporoximatelv cne metre of alluvial material h~~ been built up in the Todd River in this century. If the dam were to oroceed, the silt would gradually be scoured out by t:'le river. Build up of reeds as exists at the CasiLo causeway should be removed . ----,-------------,-