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Flood study

Spring Street Drain - Piped Drainage and Overland Flow Analysis


The Spring Street Drainage Catchment covers an area of 224 hectares draining eastwards to an outlet at West Botany Street, within the suburbs of Rockdale, Banksia, Arncliffe and Bexley, as shown in Figure 1. Stormwater ultimately drains to Botany Bay via Muddy Creek.

Overland flows within the catchment have previously resulted in damage to property and inconvenience to residents. The aim of this study is to identify and assess the properties affected by overland flows using the DRAINS and HEC-RAS computer models.


This investigation followed a general methodology for analyses of established stormwater drainage systems:

  • Compilation of data;
  • Development and testing of a "base case" computer model, representing existing or ultimate conditions;
  • Analysis for a range of design storms;
  • Identification of key problem areas;
  • Presentation of results in suitable paper and electronic formats; and
  • Provision of the models and data to Council in forms suitable for future use.

Extracts from the DRAINS model produced in the study are shown in Figures 3 and 4. This included 829 pits, 34 nodes, 572 sub-catchments, 863 pipes and channels, and 623 overflow routes. Five detention basins were used for modelling complex parts of the network where ponding and flow splits occurred. The overall percentages of paved, supplementary (impervious areas not directly connected to the pipe system) and grassed areas were 64%, 4% and 32%, respectively.

Additional Information

Field Value
Title Spring Street Drain - Piped Drainage and Overland Flow Analysis
Publication Date 1 October 2007
Themes Land and Resource Management
Spatial Extent
Map data © OpenStreetMap contributors
Council/LGA Bayside Council
Author/ Prepared by Brown Consulting (NSW) Pty Ltd
Publish date 6 July 2017
Update date 26 July 2017
River Basin 213 - Sydney Coast and Georges River
Place Name Spring Street Drainage Catchment
Approval State Approved
Submitted for approval 6 July 2017
Submitted by John Silk
Approved 26 July 2017
Approved by plattns
Data Comment

Report only; no other data. Legacy data; may have been superseded.

Identifier ac2c88ed-e5c5-486f-900a-0bddb55dd473