An 'URBS' runoff-routing model of the entire Katherine River catchment to Vampire Creek has been developed and calibrated to recorded flood data at 7 stream gauging stations. The model consists of 86 sub-catchments. The calibrated hydrologic and hydraulic models were used to estimate design flood discharges and flood levels in the area of interest. Design flood discharges were matched to the results of the flood frequency analysis. Based on the model results, flood maps showing the extent of
flooding across the hydraulic model area have been prepared for the 100 year ARI, January 1998 and Probable Maximum Flood (PMF) events. The estimated 100 year ARI flood discharge at the railway bridge is 7,950 m3/s. The estimated flood level at the railway bridge stream gauge for this event is 106.34 m AHD (19.98 m GH) - approximately 0.4 m lower than the January 1998
flood level. PMF flood levels are more than 3 m higher than 100 year ARI flood levels.,
Notes
Re-published October 2007 by the Northern Territory. Department of Natural Resources, Environment and The Arts,
The Northern Territory Department of Natural Resources, Environment and The Arts would like to advise readers that the former Department of Lands, Planning and Environment and Water Studies Pty Ltd first published this report in February 2000.,
Made available via the Publications (Legal Deposit) Act 2004 (NT).,
Table of contents
1. INTRODUCTION -- 2. CATCHMENT DESCRIPTION -- 3. METHODOLOGY -- 4. AVAILABLE DATA -- 4.1 Overview -- 4.2 Topographic Data -- 4.3 Streamflow Data -- 4.4 Stream Gauge Rating Curves -- 4.5 Katherine Floodplain Gauges -- 4.6 Peak Flood Levels -- 4.7 Pluviograph Data -- 4.8 Daily Rainfall Data -- 5. SELECTION OF CALIBRATION EVENTS -- 6. HYDROLOGIC MODELLING -- 6.1 Model Description -- 6.2 Model Configuration -- 6.3 Model Calibration -- 6.3a Calibration Methodology -- 6.3b Assignment of Total Rainfalls and Temporal Patterns -- 6.3c Adopted Model Parameters -- 6.3d Initial Losses -- 6.3e Calibration Results -- (i) Overview -- (ii) Mt Ebsworth -- (iii) Katherine Gorge and Gorge Caravan Park -- (iv) Railway Bridge -- (v) Seventeen Mile Creek and McAdden Creek -- 7. HYDRAULIC MODELLING -- 7.1 Model Description -- 7.2 CELLFLOW Model Configuration -- 7.3 Topographic Data -- 7.4 Hydraulic Structures -- 7.5 Calibration Methodology -- 7.6 Calibration Results - January 1998 Flood 357.6a Overview -- 7.6b Peak Flood Levels -- 7.6c Stage Hydrographs --
7.6d Comparison with Gauged Discharges -- 7.7 Calibration Results - March 1984 Flood -- 7.8 Calibration Results - February 1987 Flood -- 7.9 Calibration Results - January 1995 Flood -- 7.10 Summary of Calibration Results -- 8. FLOOD FREQUENCY ANALYSIS -- 8.1 Method of Analysis -- 8.2 Development of the Town of Katherine -- 8.3 Flood Data from Stream Gauging Station -- 8.3a Available Data -- 8.3b Rating Curves -- 8.3c Peak Annual Flood Data -- 8.4 Flood Data from Other Sources -- 8.4a Available Data -- 8.4b Major Floods -- 8.4c 1897 and 1914 Flood Levels -- 8.4d 1931 and 1940 Flood Levels -- 8.4e Peak Flood Discharges -- 8.5 Flood Frequency Analyses -- 8.6 ARI of the 1957 and 1998 Floods -- 8.7 Palaeohydrology -- 9. DESIGN FLOOD ESTIMATION -- 9.1 Methodology -- 9.2 Design Rainfalls -- 9.3 Rainfall Losses -- 9.4 Design Discharges -- 9.5 Estimation of PMF Discharges -- 9.6 Design Flood Levels -- 9.7 Flood Mapping -- 9.7a Estimation of Flood Extent -- 9.7b January 1998 and Design Flood Maps -- 9.7c Emergency Services Maps -- 9.8 Proposed Road and Railway Crossings -- 10. FLOOD FORECASTING MODEL -- 10.1 Adopted Model -- 10.2 Adopted Model Parameters -- 10.3 Flood Forecasting Model Results -- 10.4 Sensitivity Analyses -- 11. CONCLUSIONS --
12. REFERENCES,