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 iv LIST OF TABLES Page Table 3.1 Summary of Available Rainfall Data, Todd River Catchment 9 Table 3.2 Summary of Stream Gauging Stations and Available Stream Flow Data, Todd River Catchment 10 Table 3.3 No of Gaugings, Maximum Gauged Discharge and Estimated Maximum Flood Discharge During the Period of Record, Todd River Stream Gauges 13 Table 4.1 Adopted Calibration and Verification Events, Todd River Catchment 20 Table 4.2 Verification Event Rainfall Data, Todd River Catchment 26 Table 4.3 Verification Event Stream Gauge Data, Todd River Catchment 26 Table 5.1 Todd River URBS Model Sub-Catchment Areas 30 Table 5.2 Adopted URBS Model Global Parameters 31 Table 5.3 Adopted Calibration Event Initial and Continuing Loss Rates 31 Table 5.4 Adopted URBS Model River Reach Length Factors 33 Table 5.5 Adopted Verification Event Initial and Continuing Loss Rates 41 Table 5.6 URBS Model Verification Results, Todd River 42 Table 5.7 URBS Model Verification, Charles River and Emily Creek 43 Table 6.1 TUFLOW 1D Hydraulic Structures 46 Table 6.2 TUFLOW 2D Hydraulic Structures 47 Table 6.3 Adopted Mannings n Value 47 Table 6.4 Inflow Boundary Locations in the TUFLOW Model 48 Table 6.5 Adopted Todd River and Charles River Bed Scour Depths 49 Table 7.1 Summary of Surveyed Debris Marks and Predicted Water Levels, March 1983 Flood Event 52 Table 7.2 Summary of Surveyed Debris Marks and Predicted Water Levels, March / April 1988 Flood Event 58 Table 7.3 Summary of Recorded and Predicted Peak Water Levels, TUFLOW Verification Events 64 Table 8.1 Peak Annual Water Levels and Discharges, Todd River, 1952 to Present 66 Table 8.2 Peak Flood Discharge Estimates, Todd River at Wigley Gorge and Anzac Oval 67 Table 8.3 Flood Frequency Analysis, Todd River Catchment 70 Table 9.1 Adopted Design Rainfall Intensities, Todd River Catchment 71 Table 9.2 Adopted Areal Reduction Factors, Todd River Catchment, Design Events Up to and Including 100 Years ARI 72 Table 9.3 PMP Rainfalls for the Todd River Catchment to Heavitree Gap. 73 Table 9.4 Estimated Design Flood Discharges at Wigley Gorge, Anzac Oval and Heavitree Gap 74 Table 9.5 Comparison of Todd River Design Flood Discharge Estimates at Anzac Oval and Heavitree Gap, WRM (2006), GHD (1996) 75