Territory Stories

Alice Springs Flood Investigation and Floodplian Mapping Study

Details:

Title

Alice Springs Flood Investigation and Floodplian Mapping Study

Creator

WRM Water & Environment Pty Ltd; Northern Territory. Department of Lands, Planning & the Environment

Editor

Roads, Greg

Collection

E-Publications; PublicationNT; E-Books; EXTA1463

Date

2015-10-12

Location

Alice Springs

Description

Made available via the Publications (Legal Deposit) Act 2004 (NT).; WRM Water & Environment (WRM) was commissioned by the Department of Lands & Planning (DLP) to undertake a flood study of the Todd River in the Alice Springs area. The aim of the study is to develop a 2 dimensional flood model, which allows flood flow in a complex flood plain to be modelled, to determine the extent and severity of riverine flooding in the town of Alice Springs and the Alice Springs rural area south of Heavitree Gap. The purpose of the study is to produce floodplain maps of the Alice Springs and its rural area for land use planning and counter – disaster purposes. This study is an extension of the Alice Springs Farms Area Floodplain Mapping Study (WRM, 2006), undertaken by WRM on behalf of the Department of Planning & Infrastructure in 2006 in order to develop detailed Todd River floodplain maps for the rural area south of Alice Springs.

Table of contents

1. INTRODUCTION -- 2. CATCHMENT DESCRIPTION -- 3. AVAILABLE DATA -- 4. CALIBRATION AND AND VERIFICATION EVENTS -- 5. HYDROLOGIC MODEL CALIBRATION AND VERIFICATION -- 6. HYDRAULIC MODEL DEVELOPMENTLOPMENT -- 7. HYDRAULIC MODEL CALIBRATION -- 8. FLOOD FREQUENCY ANALYSIS -- 9. DESIGN EVENT HYDROLOY -- 10. DESIGN FLOOD LEVELS AND EXTENTS -- 11. CONCLUSION -- 12. REFERENCES

Language

English

Subject

Flood control -- Northern Territory -- Alice Springs; Flood damage prevention -- Northern Territory -- Alice Springs; Floodplain management -- Northern Territory -- Alice Springs; Alice Springs Flood Investigation; Floodplain Mapping

Publisher name

WRM Water & Environment Pty Ltd

Place of publication

Darwin (N.T.)

Series

EXTA1463

Format

vii, 95 pages : colour maps ; 30 cm.

File type

application/pdf.

Copyright owner

Check within Publication or with content Publisher.

Parent handle

https://hdl.handle.net/10070/259732

Citation address

https://hdl.handle.net/10070/494349

Page content

0269-02-C1 12 October 2015 70 Table 8.3 Flood Frequency Analysis, Todd River Catchment Annual Exceedance Probability (%) Peak Discharge (m3/s) Wigley Gorge Anzac Oval GHD (1996) WRM (2006) WRM (2011) Barlow (1988) GHD (1996) WRM (2006) WRM (2011) 50.0 130 110 96 130 130 135 103 20.0 470 305 278 375 370 340 298 10.0 710 485 461 585 600 520 490 5.0 900 705 689 820 830 725 724 2.0 1070 1065 1071 1175 1160 1060 1103 1.0 1150 1405 1428 1500 1400 1370 1447 A comparison between the different sets of results indicates that: The results at Anzac Oval are generally consistent across the 4 studies. The difference in peak discharge at Anzac Oval for the 1% and 2% AEP events between WRM (2006) and the current study are likely due to the different rating curves adopted for the gauging station in each study. The peak discharges for the more frequent events are some 15% to 25% lower for the current study when compared to Barlow (1988) and GJD (1998), most likely due to the larger dataset used available. The current study results for Wigley Gorge are somewhat different to GHD (1996) results for all events except the 2% AEP event, again most likely due to the larger data set (33 years of data compared to 50 years of data). The WRM (2006) discharge estimates are consistent with the current study. The results for Wigley Gorge and Anzac Oval obtained in the current study are similar for the full range of AEPs. Whereas the GHD (1996) results for Wigley Gorge are not consistent with their results for Anzac Oval. This inconsistency is probably due to the shorter period of record used in the GHD (1996) analysis. On the basis of the above comparison, it is recommended that the results of this study (obtained using a longer period of recorded data) be adopted.