Preliminary Review for a Drainage
Dataset
REPORT & RECOMMENDATIONS

1.0

25 January 2007
Preliminary Review for a Drainage
Dataset
REPORT & RECOMMENDATIONS

1.0

25 January 2007
Sinclair Knight Merz
7th Floor, Durack Centre
263 Adelaide Terrace
PO Box H615
Perth WA 6001 Australia
Tel: +61 8 9268 4400
Fax: +61 8 9268 4488
Web: www.skmconsulting.com
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responsibility whatsoever for or in respect of any use of or reliance upon this report by any third
party.
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Contents
1.
2.
3.
4.
Introduction
12
1.1
1.2
Project Background
Project Scope
12
12
1.2.1
Following Stages
13
1.3
Project Approach
14
1.3.1
1.3.2
1.3.3
Stage 1: Project Planning
Stage 2: Stakeholder Consultation
Stage 3: Prepare & Present Final Report
14
14
15
1.4
1.5
Glossary of Terms & Abbreviations
Stakeholder Consultation
15
16
Existing Frameworks & Practices
17
2.1
Overview of Stormwater Drainage Management in Western Australia17
2.1.1
2.1.2
2.1.3
2.1.4
Water Corporation
Local Government
Department of Water
Consulting Engineers
17
18
18
19
2.2
2.3
Key Issues Identified at the Workshop
National Data Management Practices
19
19
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
New South Wales
Northern Territory
Queensland
Tasmania
Victoria
20
20
20
20
21
2.4
D-SPEC
22
High Level Drivers for Drainage Information
24
3.1
3.2
3.3
3.4
3.5
24
24
24
25
25
Strategic Planning & Inter-Agency Coordination
Asset Management & Reporting
Water Quality
Emergency Management
Land Development
Key Business Needs
26
4.1
4.2
4.3
4.4
26
27
29
29
Operational Asset Management & Maintenance
Tactical & Strategic Asset Planning
Water Quality Management
Emergency Management
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Preliminary Review for a Drainage Dataset – Report & Recommendations
5.
Required Dataset Components
31
5.1
5.2
31
31
Dataset Components to Support Business Needs
Dataset Attributes
6.
Review of Existing Drainage Datasets
34
7.
Recommendations & Next Steps
36
7.1
7.2
7.3
36
37
40
Summary of Findings
Recommendations
High-Level Implementation Plan
Appendix A Study Participants
A.1
A.2
Interviewees
Workshop Participants
Appendix B
B.1
B.2
B.3
B.4
B.5
Business Requirements
Information About the Drainage Network
Key Issues
Solutions
Key Benefits
Appendix C
C.1
C.2
Workshop Outcomes
Stocktake of Existing Datasets
Features
Attributes
41
41
41
43
43
45
47
48
49
52
52
53
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Tables

Table 1 Key Issues Identified by Participants
19

Table 2 Operational Asset Management & Maintenance Requirements
26

Table 3 Tactical & Strategic Planning Requirements
28

Table 4 Operational Asset Management & Maintenance Requirements
29

Table 5 Network Components Required for a Drainage Dataset
31

Table 6 Data Attributes Required for a Drainage Dataset
31

Table 7 Average Data Quality Scores for LGAs With a Digital Dataset
34

Table 8 Features Stored by the LGAs With a Digital Drainage Dataset
35

Table 9 Attributes Stored by the LGAs With a Digital Drainage Dataset
35

Table 10 High Level Timelines for Following Stages
40

Table 11 Interviewees for the Study
41

Table 12 Stakeholders Who Participated in the Workshop
41

Table 13 Business Requirements Identified by Participants
43

Table 14 Business Drivers Identified by Participants
44

Table 15 Network Components Required for a Drainage Dataset
45

Table 16 Data Attributes Required for a Drainage Dataset
46

Table 17 Key Issues Faced by Participants in Working with Existing Drainage Data
47

Table 18 Suggested Solutions
49

Table 19 Key Benefits
50

Table 20 Features Stored by the LGAs With a Digital Drainage Dataset
52

Table 21 Attributes Stored by the LGAs With a Digital Drainage Dataset
53
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Document history and status
Revision
Date issued
Reviewed by
Approved by
0.1
2 November 06
James W
Dan S
Date approved
Revision type
0.2
20 December 06
Dan S
-
-
Pre-draft released for review
0.3
20 December 06
James W
-
-
Feedback to Draft 0.2
0.4
21 December 06
Dan S, Working
Group
members
Dan S
22 December 06
Draft released for review by
the Working Group
1.0
25 January 07
Dan S
Dan S
Template released for
review of document
structure
Final version released for
acceptance
Distribution of copies
Revision
Copy no
Quantity
Issued to
Printed:
15 February 2016
Last saved:
15 February 2016 06:26 PM
File name:
Author:
I:\WVES\Projects\WV03237\Deliverables\final report 1.0\Drainage Dataset Review Report
& Recommendations 1.0.doc
James Wright
Project manager:
James Wright
Name of organisation:
WALIS Office
Name of project:
Preliminary Review for a Drainage Dataset
Name of document:
Preliminary Review for a Drainage Dataset
Document version:
1.0
Project number:
WV03237
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Executive Summary
Project Scope & Approach
This document presents the findings of a high-level study designed to enable the WALIS Spatial
Management Group to determine whether the development of a single stormwater drainage
dataset1 appears feasible and viable as a State government initiative.
Stakeholder consultation for this project included:



Interviews held with key agencies (Department of Water, Water Corporation and local
government;
A brief review of data management practices nationally, undertaken via SKM’s Surface Water
Hydrology Community of Practice (a group of hydrology professionals who work with drainage
data from local government and utilities in each state);
A workshop attended by 40 participants (75% from local government and 25% from State
government) which aimed to:
–
Confirm the business requirements for an integrated dataset;
–
Identify the dataset components which would be needed (to support these requirements);
–
Identify some potential barriers we may need to consider in developing an integrated
dataset;
–
Suggest some potential solutions to overcome these barriers;
–
Identify the key benefits/level of support for developing the dataset.
Existing Frameworks & Practices
Key Stakeholders in WA
The Water Corporation (WC) are responsible for the management of the main drains and needs to
work closely with local government authorities (LGAs), since the WC drains are impacted by any
changes to an LGA’s network. The network of the WC’s main drains is maintained in a GIS with a
comprehensive set of attributes. Key issues identified are as follows.

The WC does acquire data from LGAs for planning and modelling purposes but there is no
comprehensive integration of these datasets. Data which is integrated by the WC typically
comprises of only the larger LGA-owned drains and is not loaded of maintained by the WC in
their GIS.
For this study ‘drainage dataset’ refers to a dataset which represents the surface and groundwater drainage
of stormwater runoff. This is likely to include both open and closed drains and related infrastructure, but
excludes natural drainage networks (such as rivers, lakes and aquifers).
1
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
Feedback from the WC indicates that whilst some LGAs are able to supply digital data it is rare
for this information to be available. This contrasts with the findings of the data audit which
indicate that the majority of metropolitan LGAs have a digital drainage dataset

The WC recognise the increasing focus on water quality, with the view that in future they may
be required to specify the quality of water which LGAs discharge into WC-owned drains. This
would require a more ready integration of drainage information (between LGA and WC-owned
drains).
LGAs are responsible for the management of all drains within their jurisdiction except for those
owned by the WC. Key issues identified are as follows.

There is a wide variation in the availability of drainage information between LGAs. Some LGAs
have no digital data related to the location and details of drainage assets, whilst others have
comprehensive datasets.

There is currently no uniform data quality specification for acquiring information on drainage
works from developers or consulting engineers, although an initiative is now underway to work
towards a standard for Western Australia.

A significant issue for LGAs is the cost of capturing drainage information where the data do not
exist. Feedback received from the workshop indicated that if the need for these data was
significant, then more LGAs would have captured the data already. The requirement to capture
drainage data may be lead in the future by water quality issues and requirements for more
accurately reporting on asset values.
The Department of Water (DoW) do not own or manage stormwater drainage assets. DoW, is
however the custodian of the natural drainage datasets which form an important component of any
whole of catchment drainage studies or modelling.
Consulting engineers are users of stormwater drainage information and work on behalf of other
stakeholders (such as the WC, DoW, LGAs and developers). The principal requirement for these
organisations is to source stormwater drainage information in a format which can be used in an
integrated model. There are often significant issues sourcing data from LGAs as digital data may
not be available or may not represent what has actually been built (leading to a reliance on asconstructed drawings).
Feedback from the workshop indicated similar issues with respect to the management of drainage
information, specifically:

Lack of data availability;

Usability of available data (fitness for purpose);

Data integration: data formats;

Data integration: inconsistent data model/specifications;

Support for data capture & maintenance;
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Preliminary Review for a Drainage Dataset – Report & Recommendations

Governance & data accessibility.
National Practices

In terms of asset ownership both Melbourne and Sydney have a similar structure to Perth, with
the majority of drains owned by local government and other drains owned by a single utility.

As with Perth, the quality and reliability of the data managed by LGAs varies significantly.
There are also variations in the rigour applied to sourcing data from contractors and the overall
data quality.

Nationally, there appears to be no precedent for a single consolidated stormwater drainage
dataset having been created from assets owned by LGAs and a water utility. The only
consolidated datasets are those which have been created by individual organisations for their
own assets, whether these are dedicated utilities (such as Melbourne Water), utilities which
form part of an LGA (such as Brisbane Water) or LGAs which manage smaller drains (as with
LGAs in Perth). The Department of Sustainability and Environment, Victoria has recently
commenced a project to develop a map of natural and engineered drainage. The VicMapHydro
project does have several areas of alignment with the WALIS initiative and should be
monitored as this initiative moves forward.

Also in Victoria, a standard which defines how data should be provided to LGAs by developers
has been adopted by a consortium comprising fourteen LGAs. The Consultant/Developer
Specifications for the Delivery of Digital Data to Local Government (D-SPEC) are now being
considered by a group of Perth LGAs. For LGAs on the urban fringe this will be a significant
help in obtaining and validating drainage data from developers, and represents an important
first step in setting up a quality standard for the capture and modelling of drainage data.
Business Drivers for Drainage Information
Strategic Planning & Inter-Agency Coordination
The State Water Plan (October 2006) is likely to bring an increased focus on inter-agency
coordination with respect to water management. The role of DoW, in particular will require close
cooperation with the WC and LGAs as the focus of drainage networks shifts towards aquifer
recharge, rather than the removal of stormwater. This is likely to significantly increase the need for
an integrated drainage network.
With the deployment of the Shared Land Information Platform (SLIP) there is a recognition that the
State has made a significant investment in enabling technology which facilitates the sharing of
digital land information between agencies. Local government is currently not a provider of data into
SLIP’s data services, however LGAs clearly have a critical role in contributing to an integrated
drainage dataset. SLIP presents an opportunity to leverage existing technology to support the
development and maintenance of a drainage dataset sourced from multiple custodians.
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Asset Management & Reporting
There has been an increasing requirement for agencies to be able to accurately report on the value
of their assets. For LGAs in particular this is an important driver since it requires information on the
value of their drainage network.
Water Quality
The new Public Health Act proposed for Western Australia is likely to support the increased public
awareness of water quality issues which impact our rivers and wetlands. An increased focus on
water quality (in line with a focus on integrated catchment management) will in turn drive a need for
management of the drainage network from a more holistic whole-of-catchment perspective.
Emergency Management
There is a broad recognition across LGAs that drainage data is significant in managing spills of
pollutants from emergency events. A study undertaken for FESA into the requirements for a SLIP
solution to assist in managing spills from special risk sites showed that the availability of reliable
drainage data would be a significant benefit.
Land Development
The land development activity on Perth’s urban fringe is putting pressure on stakeholder agencies
to plan and model changes to the drainage network. Whilst not a major driver for drainage
information, the availability of an integrated drainage network would assist in the planning process.
Key Business Needs
Operational Asset Management & Maintenance
This business requirement relates specifically to LGAs and the WC as the owners of the assets
which comprise the drainage network. LGAs have an obligation to maintain the stormwater
drainage assets for which they are responsible and ensure that they are functioning effectively. The
WC has a similar need to manage the asset lifecycle of the main drains for which they are
responsible. Requirements identified by workshop participants include:

To manage assets (to know what’s there and where);

To maintain the network (and ensure it is effective);

Organisational risk management.
Tactical & Strategic Asset Planning
In order to ensure that the existing and future network functions effectively, LGAs need to
undertake tactical planning to implement remedial works to address specific flood management
issues and support land development. The WC have similar needs to LGAs in supporting land
development and planning remedial works. A key business requirement for the Department of
Water (DoW) is the ability to assess the impacts of changes to the drainage network, in order to
provide guidance to developers, LGAs and the WC. Requirements identified by workshop
participants include:
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Preliminary Review for a Drainage Dataset – Report & Recommendations

To plan the design and construction/ reconstruction of drains;

Flood management/ water quantity management;

Support for Land Development;

To support consulting engineers/developers in planning and designing extensions or changes
to the network;

To ensure buried assets are protected.
Water Quality Management
The catchment planning being undertaken by DoW to manage drainage quantities also relates to
the management of water quality. In developing catchment-specific plans, DoW has a requirement
to develop guidelines on acceptable water quality for discharge from a catchment and at locations
within a catchment.
Emergency Management
There is a strong recognition by LGAs of the need to assist FESA in managing any contaminated
spillage into the drainage network. Whilst LGAs have an interest in helping to ensure that the
impacts of any spills are minimised this is primarily a business requirement for FESA.
Existing Local Government Datasets
In order to assess the availability of stormwater drainage data for the Perth metropolitan area an
audit was conducted as part of this project. This was based on a brief questionnaire sent to each of
the 30 LGAs. Responses were received from 20 LGAs, with 18 of these indicating that they have a
digital dataset. This is significant as it indicates that over half of Perth’s LGAs have created a digital
dataset. Analysis of the results indicates that:

Respondents applied a high level of confidence to the positional accuracy of their data;

Coverage across the 18 LGAs is around 75% (with wide variations);

There was a wide variation in the features and attributes stored by LGAs in their systems,
however an analysis of the components stored by most LGAs indicates that virtually all LGAs
store the same basic information about their networks. This corresponds quite well with the
basic components which would be required for flow modelling.
Key Findings From This Study
If the development of an integrated dataset is to be successful, the initiative must recognise that
each asset owner will only be willing to commit to storing information which is of use to support
internal business needs. There are three areas of data management which should be considered:
1)
The original capture of the data. Capture according to a common specification will help ensure
consistency between asset owners’ data and will ensure that common (required) features and
attributes are modelling in each organisation’s dataset.
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2)
The maintenance of the data. In recognising that each asset owner will need to maintain their
data in their own in-house systems there is no rationale for attempting to develop a common
data model which LGAs should use to store and maintain their data. However, the adoption of
a common specification for the supply of data to LGA’s is likely to support the application of
greater rigour in managing existing data held by LGAs and may support internal funding for
improving data captured prior to the adoption of the specification. For those LGAs with no
existing dataset a suggested data model may prove useful and could be developed relatively
easily from D-SPEC or a variation of D-SPEC adopted for WA.
3)
The dissemination of the data. This is the critical area for the development of an integrated
dataset. If we accept that the application of a specification will help ensure data quality, and
that asset owners are then free to model and store these data as they choose, then there must
be agreement over how the data can be output from these various systems as a common data
model for dissemination (if an integrated dataset is to be possible). This will require agreement
on the features which must be present in the dataset, and which attributes are required. Asset
owners would be free to store additional features and attributes, however the data would need
to be extracted to contain only those required under an agreed dissemination model.
The findings of the brief data audit indicate that there is commonality across the basic attributes
stored by LGAs (for example, virtually all store features for pipes and pits, and attributes for
diameter and material). This indicates that a common dissemination model which requires basic
features and attributes should be possible (although there are still some LGAs which would be
unable to supply some of these). There is commonality between the basic features and attributes
required for asset management (by the asset owners) and those required by DoW for flow
modelling. For emergency management purposes, requirements will be similar to DoW, since
FESA require the results of basic flow modelling (which may be shown as interpreted information).
Recommendations
1)
Develop a business case and an implementation plan to determine the commitment,
mechanisms and costs of implementing and maintaining an integrated stormwater drainage
dataset.
2)
Define the governance framework for managing an integrated dataset.
3)

Hold discussions with potential agencies to determine the level of support for this initiative.
Based on this brief study, DoW’s business requirements appear to have the closest
alignment with the initiative.

Determine the potential workload in maintaining an integrated dataset (for example, based
on an annual update of data from LGAs).

Determine requirements for a business case which would assist the coordinating agency
progress the initiative.
Define the scope for an integrated dataset.

Support local government in the adoption of a common specification for the capture and
supply of digital stormwater drainage data.
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Preliminary Review for a Drainage Dataset – Report & Recommendations
4)

Determine whether a suitable dataset can be developed from existing LGA data, whether
additional capture is required, or whether a partial dataset would be acceptable.

Liaise with the Department of Sustainability and Environment, Victoria to ensure that the
initiative can benefit from learnings of the VicMapHydro project.
Define a mechanism to manage an integrated dataset on an ongoing basis.

Determine the technical feasibility and costs of integrating the data.

Examine potential solutions for assisting LGAs maintain their data so that alignment with
assets owned by other LGA’s and the WC is considered. The implementation of a SLIP
node for local government could assist by providing access to asset owners’ information
as data and dissemination services.
Next Steps
Any following stages for this initiative will be subject to approval by WALIS SMG. Should SMG
approve the recommendations in this document the overall initiative could proceed as follows

Further consultation by WALIS: March-April 07;

Procurement for services to develop a business case & implementation plan: May-June 07;

Development of business case & implementation plan: July-December 07.
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1.
Introduction
This section has been taken from the Preliminary Review for a Drainage Dataset Scope of Work
document (version 1.0, 3rd November 2006).
1.1
Project Background
To address the requirements of key government strategies such as the State Water Strategy
(2003), it is strongly desirable to be able to readily compile a single drainage dataset (possibly
through a distributed Shared Land Information Platform mechanism). While not comprehensive,
the benefits include:


Potential to eliminate ‘boundary’ issues such that one local government authority’s (LGA’s)
dataset won’t match with another’s based on a shared boundary and data separation,
Potential improvements in management’s response to significant stormwater events, pollution
incidents etc.

Potential adoption of an industry best practice data standards to facilitate drainage
management

Potential to reduce fragmentation of data formats, capture methods, attribution, maintenance
A Working Group has been formed to determine the terms for the consultancy and comprises a
number of key stakeholders in the drainage field. The consultancy is being undertaken on behalf of
the Western Australian Land Information System (WALIS) Core Management Group (CMG) which
will be renamed as WALIS Spatial Management Group (SMG) from January 2007.
1.2
Project Scope
The scope of this project is to undertake a preliminary study to enable the sponsors of the study
(WALIS SMG) to determine whether the development of a single drainage dataset appears feasible
and viable as a State government initiative.
For this study ‘drainage dataset’ refers to a dataset which represents the surface and groundwater
drainage of stormwater runoff. This is likely to include both open and closed drains and related
infrastructure, but excludes natural drainage networks (such as rivers, lakes and aquifers).
The study will be restricted to surface and groundwater management in the Perth metropolitan area
between Yanchep in the north, Mundaring in the east and Mandurah in the south.
The project scope includes:

Undertaking a high-level review of the existing frameworks relevant to the management and
maintenance of a single drainage dataset, including:
–
The co-operative relationships and frameworks within the drainage community;
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Preliminary Review for a Drainage Dataset – Report & Recommendations
–
Industry best practice for drainage data management.

Identifying the high-level drivers for managing surface and groundwater drainage in different
parts of the metropolitan area;

Defining the required components for a single drainage dataset which would support the key
business needs identified by the Working Group (these will need to be clarified). Broadly,
these are:


–
The assessment of resource quantities;
–
The assessment and management of resource quality (including containment of
contaminated spillage/pollution);
–
Asset management (including the measurement of drainage network performance);
–
Network management (to reduce flooding, control flows, prevent areas of inundation);
–
The recharge of aquifers;
–
Future business needs (to be defined).
Assessing existing drainage datasets to identify the potential for their integration, associated
issues and potential maintenance processes. The ‘stocktake’ of existing datasets will include a
high-level assessment of:
–
Completeness;
–
Accuracy;
–
Currency;
–
Compatibility;
–
Maintenance processes;
–
Update frequency.
Defining a draft timetable for the following stage of the overall project.
1.2.1
Following Stages
Any future stages of the overall initiative will be subject to endorsement by WALIS, and contingent
upon the potential viability of the dataset (as defined by this project). This section has been
included to clarify the scope of this project by identifying additional work which may be required
prior to the development the dataset.
Future stages may include:

A detailed assessment of maintenance options for an integrated dataset;

An assessment of the costs of developing the dataset;

A business case for the development and ongoing maintenance of the dataset.
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1.3
Project Approach
1.3.1
Stage 1: Project Planning
Objectives

To discuss, document and agree on the project scope, approach, deliverables and timeframe.
This stage was undertaken to help ensure that SMG’s expectations for the final report were met
and provided the opportunity for the WALIS Office to make changes to the approach.
Approach
Activities
Description
Project kick-off

Draft Final Report Template
Hold an initial meeting with the Project Sponsor to agree to clarify the
project scope and required outcomes.

Hold a preliminary interview with Water Corporation stakeholders to
assess the current state of the Water Corporation dataset and known
issues in relation to LGA datasets.
Agree on the key information to be included in the final report.
Document scope of work
Prepare the scope of work document and obtain signoff.
1.3.2
Stage 2: Stakeholder Consultation
Objectives

To determine (at a high level):

–
Industry best practice and the background to drainage practices both nationally and
internationally;
–
Key business drivers for a drainage dataset in terms of broad future needs.
To gain input from stakeholders in order to assess:
–
Current and future business needs for a drainage dataset;
–
The status of their dataset (including: completeness; accuracy; currency; compatibility;
and update frequency).
–
Current data management/ maintenance practices and the use of, or adherence to
standards.
Approach
Activities
Description
Define high level business
needs
Define key business drivers for future needs and assess needs for drainage
modelling. This will be achieved by collating feedback from SKM’s Surface
Water Hydrology Community of Practice (CoP) and the WALIS Drainage
Working Group.
Review current
capture/maintenance
standards
Review leading standards and approach (including D-Spec, Melbourne
Water and WA Water Corporation).
Interview key stakeholders
Interview one LGA and two state government agencies to determine likely
issues, business needs and status of datasets. This information will be used
to help develop the questionnaire and plan the workshop.
Develop questionnaire and
Prepare a questionnaire to assess business needs, data management and
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Activities
Description
plan workshop
dataset status.
Plan the workshop.
Hold stakeholder workshop
Hold a workshop with stakeholder agencies and local government to
determine broader user requirements and dataset issues.
Workshop follow-up
Distribute findings of the workshop for comment and feedback by
stakeholders.
Phone stakeholders to clarify any significant issues which emerge in
assessing the workshop outcomes.
1.3.3
Stage 3: Prepare & Present Final Report
Objectives

To prepare and obtain formal approval for the final report.
Approach
Activities
Description
Prepare final report



Obtain formal approval



Present to WALIS SMG


1.4
Document findings based on stakeholder consultation.
Phone stakeholders to clarify any significant issues which emerge in
assessing the workshop outcomes.
Hold discussions with the Project Sponsor to clarify any key points.
Circulate the report for feedback from the Working Group.
Meet with the Working Group to review feedback.
Obtain signoff from the Project Sponsor.
Draft slides for the SMG presentation.
Present key findings to WALIS SMG.
Glossary of Terms & Abbreviations
Term/ Abbreviation
Description
AMS
Asset Management System
CMG/ SMG
The WALIS Core Management Group (CMG) which will be renamed as WALIS
Spatial Management Group (SMG) from January 2007.
CoP
Community of Practice
DoW
The Department of Water
GIS
Geographic Information System
LGA
Local government authority
SKM
Sinclair Knight Merz, the consultants who undertook this study.
WALIS
Western Australian Land Information System
WC
The Water Corporation
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1.5
Stakeholder Consultation
Initial input was gained as follows:


Interviews were conducted with key stakeholders (the Department of Water, the Water
Corporation, the City of Melville and SKM planning consultants). A list of interviewees is
provided in Appendix A
Input on best practices was sought nationally from SKM’s Surface Water Hydrology
Community of Practice (a group of hydrology professionals who work with drainage data from
local government and utilities in each state).
A workshop was then held to gain input from stakeholders. The aim of the workshop was to:

Confirm the business requirements for an integrated dataset;

Identify the dataset components which would be needed (to support these requirements);

Identify some potential barriers we may need to consider in developing an integrated dataset;

Suggest some potential solutions to overcome these barriers;

Identify the key benefits/level of support for developing the dataset.
The workshop was well attended, with a total of 40 attendees, 75% of whom represented local
government and 25% State government. A list of attendees is provided in Appendix A. Follow-up
phone calls were then used to confirm or clarify key points raised at the workshop.
To gain a picture of the status of LGA’s datasets an audit was conducted. This is outlined in
Section 6.
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2.
Existing Frameworks & Practices
2.1
Overview of Stormwater Drainage Management in Western Australia
2.1.1
Water Corporation
The Water Corporation (WC) are responsible for the management of the main drains. These are
drains typically over 700mm in diameter which may service more than one local government
authority (LGA) and which are therefore not within the jurisdiction of a single LGA. Note that in
cases some main drains are managed by LGAs.
The WC needs to work closely with LGAs, since the WC drains are impacted by any changes to an
LGA’s network. For forward planning or to assess network efficiency, the WC needs to form
sections of an integrated network which can be transferred to a flow modelling package. This
requires the WC to source data from LGAs (related to their major drains).
Dataset Overview
The network of the WC’s main drains is maintained in a GIS with a comprehensive set of attributes.
The data are maintained from as-constructed drawings supplied by developers with the data
converted to a GIS format. The focus of the data extraction process is on supporting developers,
with data supplied in CAD. A project is currently being piloted to streamline the extraction process
(the Transfer of Digital Design project) which will enable more ready data extraction in a CAD
format (DXF).
Key Issues

The WC does acquire data from LGAs for planning and modelling purposes but there is no
comprehensive integration of these datasets. Data which is integrated by the WC typically
comprises of only the larger LGA-owned drains and is not loaded of maintained by the WC in
their GIS. Any integration work is undertaken as separate studies, typically with a focus on
addressing a specific flooding issue.

Feedback from the WC indicates that whilst some LGAs are able to supply digital data it is rare
for this information to be available. This contrasts with the findings of the data audit which
indicate that the majority of metropolitan LGAs have a digital drainage dataset (discussed in
Section 6).

The data are not readily available to LGAs in a format which supports ready integration to a
GIS (for those LGAs with drainage data in this format).

The WC recognise that there is an increasing focus on water quality, with the view that in
future they may be required to specify the quality of water which LGAs discharge into WCowned drains. This would require a more ready integration of drainage information (between
LGA and WC-owned drains).
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2.1.2
Local Government
LGAs are responsible for the management of all drains within their jurisdiction except for those
owned by the WC. In cases this can include main drains, and de-commissioned drains which are
not maintained (but which may still affect sections of the network).
Significant changes can occur to LGAs drainage networks due to land development on the urban
fringe. Drainage information is typically supplied by developers as-constructed drawings.
The status of LGAs’ datasets varies significantly. Section 6 outlines the findings of the audit
conducted as part of this project.
Key Issues

There is a wide variation in the availability of drainage information between LGAs. Some LGAs
have no digital data related to the location and details of drainage assets, whilst others have
comprehensive datasets. Consequently, some LGAs do not have readily available information
on which assets they own, their location, their design specifications and their condition. The
significant lack of available spatial and associated attribute information has implications for
LGAs from an asset management and maintenance perspective, and also for other
stakeholders who need access to this information (this includes consulting engineers, the WC
and the Department of Water).

There is currently no uniform data quality specification for acquiring information on drainage
works from developers or consulting engineers as digital data which can be loaded to an
LGA’s GIS (for those LGAs with drainage data in this format). An initiative is now underway to
work towards a standard for Western Australia (as outlined in Section 2.4).

A significant issue for LGAs is the cost of capturing drainage information where the data do not
exist. Feedback received from the workshop indicated that if the need for these data was
significant, then more LGAs would have captured the data already The justification for data
capture may become easier for those LGAs which adopt a data specification. For LGAs not
experiencing significant land development, the requirement to capture drainage data may be
lead in the future by water quality issues and requirements for more accurately reporting on
asset values. This is discussed further in relation to LGAs’ business requirements in Section 4.
2.1.3
Department of Water
The Department of Water (DoW) do not own or manage stormwater drainage assets. DoW, is
however the custodian of the natural drainage datasets (for which the Department of Environment
was previously the custodian) which form an important component of any whole of catchment
drainage studies or modelling.
Data related to the natural drainage network is considered essential by DoW for modelling flows for
a catchment. The need for integrating all information which impacts catchment drainage would
need to be considered as part of any initiative to develop a single stormwater drainage dataset.
These may include engineered surface drainage, salinity drainage and licenced bores.
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2.1.4
Consulting Engineers
Consulting engineers are users of stormwater drainage information and work on behalf of other
stakeholders (such as the WC, DoW, LGAs and developers). The principal requirement for these
organisations is to source stormwater drainage information in a format which can be used in an
integrated model.
Key Issues
These are based on discussions with SKM consultants working on projects for the WC and DoW.

There are often significant issues sourcing data from LGAs due to lack of availability. Datasets
and as-constructed drawings supplied by LGAs may not reflect what has actually been built.

In undertaking a capacity review for a catchment additional information may need to be taken
into account. This includes drainage culverts constructed under roads by Main Roads, or
drainage network connections owned by industrial users.
2.2
Key Issues Identified at the Workshop
The following table presents a summarised view of the issues identified by stakeholders at the
workshop. Due to the large representation from local government these issues are primarily related
to LGAs. The original responses are provided in Appendix B.

Table 1 Key Issues Identified by Participants
Key Issue
Additional Comments
Lack of Data Availability

Usability of Available Data (Fitness for
Purpose)




Data Integration: Data Formats


Data Integration: Inconsistent Data
Model/Specifications


Support for Data Capture & Maintenance

Governance & Data Accessibility

2.3
Data have not been captured in a GIS format by most
LGAs
Due to the lack of spatial data capture, data are often not
available in a format which can be integrated.
The information which is available is not always able to be
relied upon (for example for modelling).
Lack of metadata or data quality information
Difficulties managing data quality due to staff turnover
issues
There can be difficulties updating the dataset and
maintaining multiple copies (spatial and analysis datasets)
There can be internal issues related to data/systems
integration and data conversion
Difficulties exist in relation to compatibility and
connectivity between datasets
There is a lack of standardisation of attributes and
formats
There are difficulties sourcing funding for data capture
and maintenance.
It can be difficult to source data and access maintenance
information. Custodianship for the data may be unclear.
National Data Management Practices
This section is based on discussions with members of SKM’s Surface Water Hydrology Community
of Practice and provides an overview of organisations which can be regarded as leaders in the
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management of drainage information in each state. Note that this information has been sourced
through brief discussions only and does not represent a comprehensive view of the situation in
each state.
2.3.1
New South Wales
In Sydney drainage assets owned predominantly by LGAs with some owned by Sydney Water. The
drains managed by Sydney Water are typically the open drains and older piping in the city, with
drains in newer subdivisions managed entirely by LGAs. The data managed by LGAs varies
significantly, with some LGAs having a well-structured dataset, and others virtually no data. Sydney
Water maintain their data in a GIS, however sourcing the information can be difficult.
2.3.2
Northern Territory
Stormwater drainage assets in the Darwin metropolitan area are owned and managed by three
LGAs (Darwin City Council, Palmerston City Council and Lichfield) with no overarching utility. Data
related to these assets varies between the LGAs, with Darwin City Council having captured their
stormwater drains as CAD. Palmerston piloted a capture program but this has yet to be completed.
Note that some of the drains in road reserves are owned by the Department of Planning and
Infrastructure which stores the information in as-constructed drawings.
2.3.3
Queensland
LGAs in Queensland typically have their own water authority which operates as a corporate body
within the LGA. The LGAs noted as the leading organisations which manage stormwater drainage
data well are the Brisbane City Council; Caloundra City Council and Gold Coast City Council.
Drainage assets in the Brisbane metropolitan area are owned by Brisbane Water with digital data in
a GIS format available for download via an online system (eBIMAP). Caloundra’s water authority,
CalAqua has a similar data dissemination system which allows authorised users the ability to
download their drainage data as shapefiles (Calmap). The system for Gold Coast Water is more
manual. Users are required to submit a request to the spatial group which supplies drainage data in
a MapInfo format.
References:

Brisbane City Council eBIMAP: https://obonline.ourbrisbane.com/services/home/return.do

Caloundra City Council Calmap:
http://www.caloundra.qld.gov.au/website/cityBusiness/building/property_inquiries.asp
2.3.4
Tasmania
The situation in Tasmania is similar to Queensland where LGAs have a division which functions as
a water utility in its own right. Consequently LGAs own all drainage assets in their area. Hobart City
Council, and the larger LGAs in the surrounding area (such as Clarence) have mostly captured
their drainage assets and store these in a GIS. Hobart City Council have developed some
specifications or guidelines for validating spatial data for as constructed works, however the level to
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which other LGAs have developed specifications is unknown (these appear to be restricted to
specifications for drawings only).
2.3.5
Victoria
The situation in Melbourne is similar to WA, with the majority of drains owned by LGAs, and a
single utility responsible for main drains (Melbourne Water).
Melbourne Water (MW) have a (relatively loose) specification developed for the supply of asconstructed information. Data are stored in-house in their GIS which combines spatial data stored
in MapInfo with attributes stored in an AMS. MW have bilateral agreements in place with LGAs to
supply digital data. Data are supplied to LGAs annually (although a 6-monthly update is being
considered). There has been an increasing need over the last 12-18 months for MW to acquire
data from LGAs and integrate these data into datasets which can be used to support water quality
initiatives. In integrating the data there are issues with data supplied by LGAs in different formats,
data models and levels of attribution. A further issue is the quality of the data, with some LGAs
having captured design information (rather than as-constructed information) in their datasets.
The management of drainage information between LGAs varies significantly, with few focussing on
integration with MW’s dataset (Booranda being the exception). Consortium members of D-SPEC
have appear to have implemented best practice nationally in ensuring that data supplied by
developers meets the required quality guidelines (refer to Section 2.4).
Significantly, the Department of Sustainability and Environment have initiated a project to look at
developing a map of natural and engineered drainage (VicMapHydro). The project has a focus on
developing a map with identifiers linking back to asset owners’ systems (accessible by users in
these organisations). The project has been running for around four months and is currently
defining:

What the dataset should comprise (in terms of data, functionality and accessibility to
stakeholder groups); and

A business case for the assembly of the dataset (and map).
Note that a similar initiative was being considered by Goulburn-Murray Water but has not
progressed.
References:

Melbourne Water land development manual:
http://ldm.melbournewater.com.au/content/technical_guidelines_and_requirements/introductio
n.asp
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Implications for WA

In terms of asset ownership both Melbourne and Sydney have a similar structure to Perth, with
the majority of drains owned by local government and other drains owned by a single utility.

As with Perth, the quality and reliability of the data managed by LGAs varies significantly.
There are also variations in the rigour applied to sourcing data from contractors and the overall
data quality.

Nationally, there appears to be no precedent for a single consolidated stormwater drainage
dataset having been created from assets owned by LGAs and a water utility. The only
consolidated datasets are those which have been created by individual organisations for their
own assets, whether these are dedicated utilities (such as Melbourne Water), utilities which
form part of an LGA (such as Brisbane Water) or LGAs which manage smaller drains (as with
LGAs in Perth). Note, however that Department of Sustainability and Environment’s
VicMapHydro project does have several areas of alignment with the WALIS initiative.
2.4
D-SPEC
The Consultant/Developer Specifications for the Delivery of Digital Data to Local Government (DSPEC) are a standard which defines how data should be provided to LGAs by developers. This
standard has been adopted by a consortium in Victoria comprising fourteen LGAs.
D-SPEC defines:

The physical modelling of drainage network features;

Guidelines for supplying this information to LGAs;

A data model for storing and identifying network features in a CAD file;

Required attributes to be supplied with the CAD file;

Details of validation checks to be performed on the data for compliance with the specification.
Whilst the intent is that consultants will move to supplying data in a GIS format, the specifications
currently only support the supply of data in CAD (they do not contain a data model for supply in a
GIS format).
It should be noted that the intent of D-SPEC is to apply a standard specification which ensures that
data are provided to LGAs according to pre-defined quality guidelines. The focus of the
specification is on the supply (and quality assurance) of the data provided to LGAs, not how LGAs
choose to process and store the data once they receive it. D-SPEC does not contain a data model
defining how LGAs model this information in a GIS or asset management system (AMS), however
each LGA’s data model would need to align with:

The attribute tables and fields listed in D-SPEC;

The validation rules on these fields;

The domain (look-up table) values used.
Whilst Consortium members will need to do some post-processing of D-SPEC compliant data
before loading it into their systems (notably a conversion from CAD) the closer the alignment
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between the D-SPEC CAD data model and these agencies’ GIS data models then the simpler the
conversion will be.
Feedback from Melbourne Water indicates that the usefulness of D-SPEC for a utility is limited
since the effort required to format the data by developers, and then to validate it can exceed the
effort of capturing the data for main drains from plans supplied by developers. D-SPEC has lead to
improvements in data quality, however and provides an assurance that data acquired through
these specifications is based on as-constructed works and not on design plans.
Implications for WA

A group is in the process of being formed to look at an implementation of D-SPEC in Western
Australia (including possible changes to suit use in the State). For LGAs on the urban fringe
this will be a significant help in obtaining and validating drainage data from developers, and
represents an important first step in setting up a quality standard for the capture and modelling
of drainage data. Currently this initiative is being supported by a group of approximately ten
LGAs on the urban fringe.

An adoption of D-SPEC (or a variation of it) would assist LGAs who are considering a data
capture program as it provides the basis for developing a GIS data model (this could be
developed quite simply from the existing CAD specifications).

In adopting a specification for data supply, LGAs in WA would still be free to model the data in
their GIS/AMS as they wish. This is important, as those LGAs with existing GIS datasets would
need to be accommodated in any widespread adoption of the specification.
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3.
High Level Drivers for Drainage Information
This section sets out the key drivers identified by workshop participants and through stakeholder
interviews. The original responses from the workshop are provided in Appendix B.
3.1
Strategic Planning & Inter-Agency Coordination
The Water Policy Framework and the proposed Water Planning Framework set out in the Draft
State Water Plan (October 2006) are likely to bring an increased focus on inter-agency
coordination with respect to water management. The role of DoW, in particular will require close
cooperation with the WC and LGAs. LGAs are also likely to require a greater focus on integrated
catchment management in line with an increased focus on water quality (discussed below) and
water quantity. Traditionally, the drainage network has been designed to remove runoff from
catchments. Increasingly, the focus is shifting to achieving a balance where post-development
drainage mirrors that which occurred in catchments pre-development. This requires a focus on
aquifer recharge, rather than the removal of stormwater.
These trends are likely to significantly increase the need for an integrated drainage network which
enables stakeholder organisations to model planned changes to catchments and assess the
impacts on its effectiveness.
With the deployment of the Shared Land Information Platform (SLIP) there is a recognition that the
State has made a significant investment in enabling technology which facilitates the sharing of
digital land information between agencies. Local government is currently not a provider of data into
SLIP’s data services, however LGAs clearly have a critical role in contributing to an integrated
drainage dataset. SLIP presents an opportunity to leverage existing technology to support the
development and maintenance of a drainage dataset sourced from multiple custodians.
3.2
Asset Management & Reporting
There has been an increasing requirement for agencies to be able to accurately report on the value
of their assets. For LGAs in particular this is an important driver since it requires information on the
value of their drainage network.
3.3
Water Quality
The new Public Health Act proposed for Western Australia is likely to support the increased public
awareness of water quality issues which impact our rivers and wetlands. An increased focus on
water quality (in line with a focus on integrated catchment management) will in turn drive a need for
management of the drainage network from a more holistic whole-of-catchment perspective. To
date, the focus of drainage information has been more on the management of assets owned by a
specific LGA or the WC. Note that whilst the WC and LGAs do not have specific responsibilities to
manage water quality, the WC may require LGAs to conform to water quality guidelines for
discharge into their drains. LGAs also have an interest in working with ratepayers and industry in
ensuring that the quality of water flowing into drains is appropriate.
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3.4
Emergency Management
There is a broad recognition across LGAs that drainage data is significant in managing spills of
pollutants from emergency events. A study undertaken for FESA (by SKM) into the requirements
for a SLIP solution to assist in managing spills from special risk sites showed that the availability of
reliable drainage data would be a significant benefit.
3.5
Land Development
The land development activity on Perth’s urban fringe is putting pressure on stakeholder agencies
to plan and model changes to the drainage network. Whilst not a major driver for drainage
information, the availability of an integrated drainage network would assist in the planning process
(it can, for example take consulting engineers up to two months to assemble the drainage data they
require from agencies2).
2
SKM Water Engineering group, personal communication.
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4.
Key Business Needs
This section outlines the main business functions which organisations require drainage information
to support. The intent of this section is to lay the foundation in developing an understanding of what
organisations need drainage information for, and what dataset components (at a high level) would
be required to support these needs.
4.1
Operational Asset Management & Maintenance
This business requirement relates specifically to LGAs and the WC as the owners of the assets
which comprise the drainage network.
Local Government
LGAs have an obligation to maintain the stormwater drainage assets for which they are responsible
and ensure that they are functioning effectively. Since the network was primarily designed to
remove stormwater from catchments, the network’s function is focussed on preventing or reducing
flooding and draining waterlogged areas.
In line with this obligation, the principal business need for LGAs is the management of their assets,
and more significantly their maintenance (to ensure they are working effectively). In particular,
LGAs need to know which assets the organisation is responsible for, the details of these assets
(their age, material, pipe levels and so on) and where they are.
Water Corporation
The WC has a similar need to manage the asset lifecycle of the main drains for which they are
responsible. From an asset maintenance perspective the WC’s business needs are essentially the
same as LGAs in ensuring that the main drains are enabling effective drainage of their inflow. Note
that the focus of the WC’s data management is on only those drains for which the WC is
responsible.
Workshop Findings
Specific business requirements identified at the stakeholder workshop are listed below. Note that
these have been grouped or summarised to remove duplication. The original responses are
provided in Appendix B.

Table 2 Operational Asset Management & Maintenance Requirements
Business Need
Additional Comments
To manage assets (to know what’s there and
where)





To maintain the network (and ensure it is


Requires an accurate/current spatial dataset with
meaningful attributes – transparent datasets
The ‘what’ condition of data – age, material, levels
Knowledge of ownership between authorities
Consent is main driver – maintenance, know what
we’ve got, harvesting & re-use
Long term management based on planning and
budgeting needs
Maintenance of the asset is the key point.
Operational management of drainage systems on
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Business Need
Additional Comments
effective)
a day-to-day basis
Organisational risk management

Financial, environmental, social
The key information required to support these requirements for local government is likely to
comprise details of:

Asset locations;

Asset ownership;

Basic details (such as age, material, pipe levels);

Asset condition; and

Asset value.
Information requirements for the WC are not listed as the WC has a well-defined data structure in
its current dataset.
4.2
Tactical & Strategic Asset Planning
Local Government
In order to ensure that the existing and future network functions effectively, LGAs need to
undertake tactical planning to:

Implement remedial works to address specific flood management issues;

Support land development (both for new and infill subdivisions).
Strategic planning at a whole-of-catchment level is less of a focus for LGAs. A greater focus is
tactical planning of the network to assess the impacts and requirements of land development.
Water Corporation
The WC have similar needs to LGAs in supporting land development and planning remedial works.
The key difference for the WC however, is that in assessing network efficiency there may be a
requirement to model the main local government drains from more that one LGA. This requires WC
to take a more holistic view of the overall network and places an increased emphasis on the need
for data which is reliable and can be integrated to form a single network.
Department of Water
A key business requirement for the Department of Water (DoW) is the ability to assess the impacts
of changes to the drainage network, in order to provide guidance to developers, LGAs and the WC.
This requirement is related to the management of both water quantity and quality (water quality
issues are discussed in a following section).
Currently, DoW are focussing on preparing integrated management plans at the catchment level
which will support the development of guidelines for drainage management (with a focus on
ensuring that catchment discharge is similar to pre-development conditions). Since DoW’s role is
focussed on catchment stability (rather than drainage efficiency) DoW needs to be able to model
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drainage behaviour at a far more detailed level than LGAs and the WC. DoW therefore have a
stronger need for detailed, accurate and reliable information which can be readily integrated as a
network model.
Workshop Findings
Specific business requirements identified at the stakeholder workshop are listed below 3. Note that
these are collated requirements from multiple stakeholders (with a strong LGA representation) and
do not reflect the specific requirements of DoW.

Table 3 Tactical & Strategic Planning Requirements
Business Need
Additional Comments
To plan the design and construction/
reconstruction of drains



Flood management/ water quantity management



Engineering solutions to localised drainage
management issues
Stormwater treatment planning
Strategic planning of development
To model the behaviour/ efficiency of the network
during flood and/or day-to-day events
Recording flood event data helps to examine
capacity and upgrades
To assess the volume of water discharged from a
catchment
Support for Land Development
To support consulting engineers/developers in
planning and designing extensions or changes
to the network

To identify potential restrictions on a development
or subdivision of land in previously developed
sites. Infill of sites & new uses of old sites.
To ensure buried assets are protected

One Call system (Dial Before You Dig).
Information to be on Council websites (also
required to support development)
The key information required to support these requirements for local government is likely to be as
follows:

More detailed information in relation to asset specifications (such as design criteria) to assess
the impacts of changes to the network;

Sufficient information would be required to enable flow modelling of the network. Note that this
is unlikely to require additional information, but is dependent upon accurate and reliable
information which can be readily integrated to form an overall model;

For strategic planning information would be required on related datasets (such as topography,
vegetation and environmental information).
For DoW, requirements are likely to be similar, with a greater focus on:

The ability to access to a broader range of related datasets.
3
Note that these have been grouped or summarised to remove duplication. The original responses are
provided in Appendix B.
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
4.3
The ability to integrate datasets and use them for reliable flow modelling.
Water Quality Management
The catchment planning being undertaken by DoW to manage drainage quantities also relates to
the management of water quality. In developing catchment-specific plans, DoW has a requirement
to develop guidelines on acceptable water quality for discharge from a catchment and at locations
within a catchment. This in turn drives a need for a detailed drainage model for a catchment which
can model flows from day-to-day events.
There is a strong recognition from the asset owners (WC and LGAs) that water quality will become
an increasingly pressing issue and existing legislation is more widely enforced and as new
legislation (such as the Health Act) is adopted.
Workshop Findings
Specific business requirements identified at the stakeholder workshop are listed below. Note that
these have been grouped or summarised to remove duplication. The original responses are
provided in Appendix B.

Table 4 Operational Asset Management & Maintenance Requirements
Business Need
Additional Comments
Water Quality Management



To assess the quality of water discharged from a
catchment (has planning implications)
Management of the drainage & waterways
interface
Location of endpoints
The key information required to support these requirements for DoW is likely to be as follows:

Greater detail on the network which allows day-to-day flows to be modelled;

Information on the catchment as a whole (land use, vegetation, other hydraulic
characteristics).
For the WC the focus is likely to be the location of LGA-owned drains which connect with WC
drains (to enable water quality to be monitored). There is no clear information requirement for
LGAs to support this business need, however LGAs may require similar catchment-related
information to DoW in working with stakeholders to help facilitate water quality improvement.
4.4
Emergency Management
There is a strong recognition by LGAs of the need to assist FESA in managing any contaminated
spillage into the drainage network. Whilst LGAs have an interest in helping to ensure that the
impacts of any spills are minimised this is primarily a business requirement for FESA. In the case of
a hazardous materials (HAZMAT) event FESA need to be able to define:
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
Where the inlets to the drainage network are;

Where these drain to; and

How long any contaminated materials may take to travel along drains.
It is essential for FESA to identify where any spillage will drain to as quickly as possible in order to
prevent or minimise any contaminants reaching the natural drainage network or aquifers.
The key information required to support these requirements is likely to be as follows:

The location of the drainage network;

Key information which will determine the flow rate of any contaminants (such as flow direction,
pipe segment length and slope);

Any assets which will impact on the flow of contaminants (such as gross pollutant traps);

Asset ownership; and

The location of any parts of the natural drainage network which drains discharge into (such as
streams or wetlands).
Note that for emergency management use, a key issue will be the availability of this information
across LGA boundaries in a common, reliable format.
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5.
Required Dataset Components
5.1
Dataset Components to Support Business Needs
The following table presents a summary of the components required for a drainage dataset (based
on the findings of the stakeholder workshop). Further detail is provided in Appendix B, Section B.2.

Table 5 Network Components Required for a Drainage Dataset
Dataset Component
Pipe sections
Property connections
Pits/ access points (including grates & gullies)
Compensation basins/ sumps
Pumping systems
Surface drains
Interface with other drainage systems
Points where drains enter other water bodies eg – Rivers
Onsite storage, defines LGA & NC responsibilities
Drop structures, weirs, gross pollutant traps
Water quality sampling points
Catchment areas
Access/easements
Groundwater levels
Major overland flow paths
5.2
Dataset Attributes
The following table presents a summary of the attributes required for a drainage dataset. This is
based on the findings of the stakeholder workshop (as shown in Appendix B, Section B.2) with
requirements added for the WC, DoW , the City of Melville (CoM) and FESA based on brief
interviews.

Table 6 Data Attributes Required for a Drainage Dataset
Information About Network Components
DoW
WC
CoM
FESA
Pipes/ Surface drains




Pipe diameter




Pipe section length




Pipe material




Pipe type (open/closed)




Pipe depth (is it in ground water?)




Pipe invert levels (upstream/ downstream)




Pipe grade (slope)




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Information About Network Components
DoW
WC
CoM
FESA
Pipe flow direction




Pipe shape (cross section)




Pipe bedding material (yes/no)




Pipe condition




Pipe construction date (age)




Pipe design characteristics/ capacity




Pipe construction company




Pipe as-constructed plan no.




Pipe value




Pipe cost




Pipe ownership




Pipe ownership contact details




Date data was collected




Surface drain depth and width




Surface drain cross section




Pits/ Flood storage areas




Pit size/ dimensions/ capacity (side length and width or diameter)




Pit type




Pit depth




Pit inlet capacity




Connected to outlet level




Pit finished surface level




Pit lid type




Pit or outlet ownership




Pit ownership contact details




Special features (including baffles/weep points/ gross pollutant traps)




Pit inlet capacity




Dewatering/ base type/ soil type




Pit condition




Pit construction date (age)




Compensation basin/ sump size




Infiltration decrease discharge to aquifer




Water quality




Sampling locations




Catchment areas




Catchment surface cover




Characteristics – soil type (permeable etc), land use




Area




Outlet type (sump/river/lake)




Property connections




Flow quality (limit)




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Information About Network Components
DoW
WC
CoM
FESA
Business type




Catchment area




Onsite basic storage




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6.
Review of Existing Drainage Datasets
In order to assess the availability of stormwater drainage data for the Perth metropolitan area an
audit was conducted as part of this project. This was based on a brief questionnaire sent to each of
the 30 LGAs to assess:

The existence of a digital stormwater dataset;

The quality and currency of each dataset;

The components of each dataset (geographical features stored and attributes recorded). Note
that this included both attributes stored in a GIS format and those stored in an AMS which is
capable of being linked to a spatial dataset.
Responses were received from 20 LGAs, with 18 of these indicating that they have a digital
dataset. This is significant as it indicates that over half of Perth’s LGAs have created a digital
dataset.
The following table summarises the results for data quality by showing the average percentage
score for the 18 LGAs. This indicates that:

Respondents applied a high level of confidence to the positional accuracy of their data;

Coverage across the 18 LGAs is around 75%. There was a reasonable variation in the
completeness of LGAs data (responses ranged from 20%-98%).

Table 7 Average Data Quality Scores for LGAs With a Digital Dataset
Item
Description
Average Response
(of 18 LGAs)
Positional confidence (%)
How confident are you that the data are positionally
accurate?
84%
Attribute accuracy (%)
How accurate are the attributes in the dataset?
68%
Logical consistency (%)
What is your level of confidence in the structure of
the dataset's geometry? (how well the features
connect within the dataset and to other related
datasets).
70%
Completeness (%)
How complete are the data (as a representation of
relevant stormwater drainage within the geographic
extent of the dataset?)
75%
The following tables summarise the typical components and attributes of LGA’s datasets. These
show only those components and attributes stored by at least half of the 18 LGAs with a dataset
(the full list is shown in Appendix C). Key points to note are as follows:

Some LGAs store significantly more features and attributes, whilst others have captured more
basic information;
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
The information shown in the following tables can be regarded as the key information required
for a drainage dataset in terms of showing basic information on assets and in enabling the
dataset to be used for flow modelling. It does however lack some attributes (notably pipe and
pit type and pit dimensions). Other than these attributes it is much the same as the information
required by WC, DoW and CoM (as shown in Table 6 Data Attributes Required for a Drainage
Dataset).

Table 8 Features Stored by the LGAs With a Digital Drainage Dataset

Features
Percentage of
LGAs
Number of
LGAs
Pipe sections
100%
18
Pits/ access points
89%
16
Table 9 Attributes Stored by the LGAs With a Digital Drainage Dataset
Attributes
Percentage of
LGAs
Number of
LGAs
Pipe Attributes
Diameter
89%
16
Material
89%
16
Length
78%
14
Pipe number or identifier
78%
14
Invert level (upstream and/or downstream)
72%
13
Street name
61%
11
Pit number or identifier
78%
14
Lid type
56%
10
Cover level/ finished surface level
50%
9
Street name
50%
9
Pit Attributes
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7.
Recommendations & Next Steps
7.1
Summary of Findings
There is strong support for a standard drainage data specification within local government. The key
business need appears to be asset management, especially the maintenance of assets to ensure
that the drainage network within each LGA’s jurisdiction is performing effectively.
It should be recognised that a data specification is essentially a QA mechanism for ensuring that
spatial data:

Adhere to defined quality criteria in their capture;

Contain the required feature types and attributes so that they can be converted and/or
imported into each LGA’s own data model.
Given that the majority of Perth metropolitan LGAs do have an existing spatial drainage dataset,
then logically any specification adopted for WA would need to ensure that data can be readily
imported into the existing data models and systems used by LGAs.
The data captured by LGAs and the WC is focussed (as would be expected) on the business
needs of each organisation. This is much the same with councils and utilities nationally, where brief
research indicated that there is no example of multiple councils working in partnership (either
together or with a central water utility) to create an integrated stormwater drainage dataset. In the
various states, whilst there are some good examples of data being comprehensively captured, or
specifications being applied for the supply of data, however in each case the organisation
concerned has established these mechanisms for internal business needs only. If the development
of an integrated dataset is to be successful, it seems that the initiative must recognise that each
asset owner will only be willing to commit to storing information which is of use to support internal
business needs. In developing an integrated dataset there are three areas of data management
which should be considered:
1)
The original capture of the data. Capture according to a common specification will help ensure
consistency between asset owners’ data and will ensure that common (required) features and
attributes are modelling in each organisation’s dataset.
2)
The maintenance of the data. In recognising that each asset owner will need to maintain their
data in their own in-house systems there is no rationale for attempting to develop a common
data model which LGAs should use to store and maintain their data. However, the adoption of
a common specification for the supply of data to LGA’s is likely to support the application of
greater rigour in managing existing data held by LGAs and may support internal funding for
improving data captured prior to the adoption of the specification. For those LGAs with no
existing dataset a suggested data model may prove useful and could be developed relatively
easily from D-SPEC or a variation of D-SPEC adopted for WA.
3)
The dissemination of the data. This is the critical area for the development of an integrated
dataset. If we accept that the application of a specification will help ensure data quality, and
that asset owners are then free to model and store these data as they choose, then there must
be agreement over how the data can be output from these various systems as a common data
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model for dissemination (if an integrated dataset is to be possible). This will require agreement
on the features which must be present in the dataset, and which attributes are required. Asset
owners would be free to store additional features and attributes, however the data would need
to be extracted to contain only those required under an agreed dissemination model.
The findings of the brief data audit indicate that there is commonality across the basic attributes
stored by LGAs (for example, virtually all store features for pipes and pits, and attributes for
diameter and material). This indicates that a common dissemination model which requires basic
features and attributes should be possible (although there are still some LGAs which would be
unable to supply some of these). The initial interviews held with DoW, WC and CoM indicate that
there is commonality between the basic features and attributes required for asset management (by
the asset owners) and those required by DoW for flow modelling. This is to be expected, since flow
models require only basic attributes to determine flow direction, capacity and flow rate, whereas for
asset management and maintenance purposes asset owners require significantly more information.
The data model used by WC, for example contains 23 attributes related to a compensation basin.
For emergency management purposes, requirements will be similar to DoW, since FESA require
the results of basic flow modelling (ideally showing interpreted information such as flow direction
arrows). This suggests that those agencies which require an integrated dataset (DoW and FESA)
would be able to access the attributes they require largely based on attributes and features which
those LGAs with a dataset have already captured. It should be noted, however that for LGAs with
datasets which lack these required attributes, the cost of additional capture could be significant and
difficult to justify.
7.2
Recommendations
1. Develop a business case and an implementation plan to determine the commitment,
mechanisms and costs of implementing and maintaining an integrated stormwater drainage
dataset.
Rationale
Further investigation is necessary to determine:

the support for the initiative by a coordinating State agency;

whether a suitable dataset can be developed from existing LGA data, whether additional
capture is required, or whether a partial dataset would be acceptable;

the costs of integrating and maintaining the data;

the technical feasibility of integrating the data.
The following recommendations relate to work which should be considered in developing a
business case and implementation plan.
2. Define the governance framework for managing an integrated dataset.
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Rationale

In developing and maintaining an integrated dataset there will need to be a single agency
which takes responsibility.

Asset owners will need to maintain their data in their own systems, however these data could
be supplied to a coordinating agency for integration into a single dataset. This is a similar
approach taken by Main Roads in integrating data for both local government and Main Roads’
assets. The adoption of an agreed data model for supply of the data to the coordinating
agency will greatly assist the integration of data sets from LGAs.
Specific recommendations:

Hold discussions with potential agencies to determine the level of support for this initiative.
Based on this brief study, DoW’s business requirements appear to have the closest alignment
with the initiative.

Determine the potential workload in maintaining an integrated dataset (for example, based on
an annual update of data from LGAs).

Determine requirements for a business case which would assist the coordinating agency
progress the initiative.
3. Define the scope for an integrated dataset.
Rationale

The scope and feasibility of creating an integrated dataset is likely to depend on:
–
the availability of common features and attributes across the existing datasets held by
asset owners; and
–
the ability to extract and assemble these datasets to a single data model;
–
the willingness of asset owners to supply their data and make them available to
stakeholder groups.
This will require agreement to be reached between stakeholders on what the common features and
attributes should be, and agreement over which groups should have access. The scope of the
integrated dataset is likely to depend on a balance being achieved between required data and that
which is available and can be readily integrated.
Specific recommendations:

Support local government in the adoption of a common specification for the capture and supply
of digital stormwater drainage data.
The adoption of a common specification by a group of LGA’s (around eight) will require LGAs
to consider the required features and attributes which they need to acquire for their existing
systems and data models. This will help these LGAs define common elements which could
then be considered in developing a common data model for dissemination. Whilst the
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specification is likely to be adopted by less than a third of Perth’s councils, it will set a
precedent as a standard for data capture which LGAs considering a data capture program
could use as a starting point. Note that the intent is that WALIS would support LGAs in this
initiative, not undertake the actual definition of a specification (which would be the
responsibility of LGAs, possibly with input from the Institute of Public Works Engineering
Australia).


Determine whether a suitable dataset can be developed from existing LGA data, whether
additional capture is required, or whether a partial dataset would be acceptable. Specifically:
–
Work with key stakeholders (DoW, FESA, local government and the Water Corporation) to
define the features and attributes which will be required for a data model for an integrated
dataset. Define which dataset components are available now and may be available in the
future.
–
Develop an agreed data model based on a balance of requirements, available data and
the capability of asset owners to extract the required information.
–
Determine access restrictions which asset owners would require.
Liaise with the Department of Sustainability and Environment, Victoria to ensure that the
initiative can benefit from learnings of the VicMapHydro project.
4. Define a mechanism to manage an integrated dataset on an ongoing basis.
Rationale

There needs to be a viable and costed model for sourcing data from asset owners and
integrating the data in a single dataset.

LGAs maintaining drainage data will need to ensure alignment with assets held by
neighbouring LGAs and the WC.

For LGAs to support this initiative the extraction of data from their systems should impose a
minimal overhead.
Specific recommendations:


Determine the technical feasibility and costs of integrating the data:
–
Examine the impacts on asset owners in extracting the required information from existing
systems.
–
Examine the options for technical solutions which would assist the extraction process
and/or the supply of data to a coordinating agency.
Examine potential solutions for assisting LGAs maintain their data so that alignment with
assets owned by other LGA’s and the WC is considered. The implementation of a SLIP node
for local government could assist by providing access to asset owners’ information as data and
dissemination services.
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7.3
High-Level Implementation Plan
Any following stages for this initiative will be subject to approval by WALIS SMG. Should SMG
approve the recommendations in this document the overall initiative could proceed as follows (note
that these timelines are very preliminary).

Table 10 High Level Timelines for Following Stages
Stage
Preliminary Timeline
Approval by SMG
February 07
Further consultation by WALIS
March-April 07
Procurement for services to develop a business
case & implementation plan
May-June 07
Development of business case & implementation
plan
July-December 07
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Appendix A Study Participants
A.1
Interviewees
Table 11 Interviewees for the Study

Organisation
Interviewee
Department of Water
Bill Till
Christian Zammit
Water Corporation
Mark Tonti
Richard Forrest
David Bullfield (by phone)
City of Melville
Philip Gale
Melbourne Water
Keith Wesley (by phone)
Department of Sustainability
and Environment, Victoria
Peter Ramm (by phone)
A.2

Workshop Participants
Table 12 Stakeholders Who Participated in the Workshop
Organisation
Attendee
City of Belmont
Jim Polinelli
Patrick Tan
City of Canning
Doug Martin
City of Cockburn
Gary Chin
Grant Musto
Gunther Schlomer
City of Cottesloe
Luke Handcock
City of Fremantle
Ross Bishop
City of Gosnells
Darryl Browning
Jack Dowling
City of Joondalup
Chris Simms
City of Mandurah
Mary Maher
Michael Gunton
City of Melville
Ian McCormick
Phillip Gale
City of Rockingham
Brett Finlay
Rex Ballard
City of South Perth
Andrew Crotty
City of Sterling
Bill Davis
City of Sterling
Igor Veljanoski
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Organisation
Attendee
City of Subiaco
Cherie Little
City of Swan
Adrian Wong
Andrew Mugge
Arthur Colyvas
DEC (CALM)
Steve Jones
Dept of Water
Belinda Quinton
Chris Roach
Peter Kata
DLI
Julie Goodgame
Marty Stamatis
DPI
Andrea Zappacosta
FESA
Claire Howke
JDA
Suzanne Pantry
Town of Bassendean
John Chen
Town of Bayswater
Rod Woodford
Town of Claremont
David Belleville
Town of Mosman Park
Drew France
Town of Victoria Park
Melissa Gaikhorst
Terry McCarthy
Town of Vincent
Craig Wilson
Water Corporation
David Bulfield
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Appendix B Workshop Outcomes
B.1
Business Requirements
Participants were asked to define their organisations’ key business needs for a stormwater
drainage dataset. Each group was then asked to collate their requirements. The following table
shows the results, with headings added to group common themes. Requirements noted as
significant or critical have been marked with a double tick.
Table 3
Table 4
Table 5
Business Need
Table 2
Table 13 Business Requirements Identified by Participants
Table 1

To manage assets:

The ‘what’ condition of data – age, material, levels

Knowledge of ownership

Consent is main driver – maintenance, know what we’ve got,
harvesting & re-use

Maintenance of the asset is the key point
To maintain the network (and ensure it is effective)










Management of asset (long term based on planning and budgeting
needs)





To know what’s there and where.

Accurate/Current Spatial Dataset – meaningful attributes –
transparent datasets
Operational management of drainage systems on a day-to-day basis










Knowledge of asset ownership between authorities





Organisational risk management – financial, environmental, social





Tactical/ Strategic Asset Planning





Engineering solutions to localised drainage management issues





To plan the design and construction of drains





Planning and construction/ reconstruction





Flood management/ water quantity management





Recording flood event data helps to examine capacity and upgrades





Strategic Planning of Development





Stormwater Treatment Planning



 
To model the behaviour/ efficiency of the network during flood and/or
day-to-day events





To assess the volume of water discharged from a catchment





Support for Land Development





To identify potential restrictions on a development or subdivision of land
in previously developed sites. Infill of sites & new uses of old sites.





To support consulting engineers/developers in planning and designing
extensions or changes to the network





To ensure buried assets are protected





Operational Asset Management & Maintenance
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Table 5
Table 4
Table 3
Table 2
Business Need
Table 1
Preliminary Review for a Drainage Dataset – Report & Recommendations
One Call system (Dial Before You Dig). Information to be on Council
websites (also required to support development)
Water Quality Management





Water Quality Management (has planning implications)





Emergency/Incident Management, to contain contaminated spillage/
pollution





To assess the quality of water discharged from a catchment





Management of the drainage & waterways interface





Location of endpoints





The following table lists the key drivers identified by participants in relation to their business needs
(headings have been added to group drivers together).
Table 54
Table 4
Table 3
Drivers
Table 2
Table 14 Business Drivers Identified by Participants
Table 1

Strategic Planning & Inter-Agency Coordination
Integrated management of catchments





Coordination with other utilities and agencies (FESA, Dept Water etc)





Development of common skill sets & processes across
organisations/government bodies





Local government requests





Asset Management & Reporting





Management and reporting on assets and their value





Flood management





Emergency Management





Protection of people, property & environment in emergencies





Water Quality





Improvement of Ecological Health





Land Development





Development /expansion needs (eg high density)





Legislative Requirements





Legislative requirements (existing & future). Note: This relates to a
number of areas.





4
Drivers listed under Business Needs.
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Preliminary Review for a Drainage Dataset – Report & Recommendations
B.2
Information About the Drainage Network
Based on the business needs identified in the previous section, participants were asked to identify:

Which components of the network they would need to have modelled in a dataset (geographic
features);

What information would be needed to describe components of the network (attributes for
geographic features).
The results are provided in the following two tables. Note that these are listed as provided by
participants and have not been structured as a data model. An additional column has also been
added based on specific requirements supplied by FESA.

Table 15 Network Components Required for a Drainage Dataset
Table 1
Table 2
Table 3
Table 4
Table 5
FESA
Dataset Component
Pipe sections






Property connections






Pits/ access points (including stormwater grates & gullies)






Compensation basins/ sumps






Pumping systems






Surface drains






Interface with other drainage systems






Points where drains enter other water bodies eg – Rivers






Onsite storage, defines LGA & NC responsibilities






Drop structures, weirs, gross pollutant traps






Water quality sampling points






Catchment areas






Access/easements






Groundwater levels






Major overland flow paths






Notes on the following table:

A number of participants stressed the importance of location. This is assumed as being a
prerequisite for a drainage network and is not listed as an attribute.

Unique feature identifiers are not listed as this will be dependent on the data model adopted
(for example, if pipes and surface drains are modelled as different feature classes then a
unique identifier field would be needed for each). It should be noted that unique identifiers
would need to be established across a single network dataset.

Attributes for different types of flood storage areas (pits, sumps, compensation basins) have
been grouped together as responses from participants varied in how this information was
provided.
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Table 5
Information About Network Components
Table 4
Table 16 Data Attributes Required for a Drainage Dataset
Table 3

Table 2
Information related to data accuracy has been excluded as this would form part of the
metadata for a spatial dataset (positional accuracy in particular was noted as being important
information).
Table 1

Pipes/ Surface drains





Pipe diameter





Pipe section length





Pipe material





Pipe type (open/closed)





Pipe depth (is it in ground water?)





Pipe invert levels (upstream/ downstream)





Pipe grade (slope)





Pipe flow direction





Pipe shape (cross section)





Pipe bedding material (yes/no)





Pipe condition





Pipe construction date (age)





Pipe design characteristics/ capacity





Pipe construction company





Pipe as-constructed plan no.





Pipe value





Pipe cost





Pipe ownership





Pipe ownership contact details





Date data was collected





Surface drain depth and width





Surface drain cross section





Pits/ Flood storage areas





Pit size/ dimensions/ capacity (side length and width or diameter)





Pit type





Pit depth





Pit inlet capacity





Connected to outlet level





Pit finished surface level





Pit lid type





Pit or outlet ownership





Pit ownership contact details





Special features (including baffles/weep points/ gross pollutant





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PAGE 46
Table 5
Table 4
Table 3
Table 1
Information About Network Components
Table 2
Preliminary Review for a Drainage Dataset – Report & Recommendations
traps)
Pit inlet capacity





Dewatering/ base type/ soil type





Pit condition





Pit construction date (age)





Compensation basin/ sump size





Infiltration decrease discharge to aquifer





Water quality





Sampling locations





Catchment areas





Catchment surface cover





Characteristics – soil type (permeable etc), land use





Area





Outlet type (sump/river/lake)





Property connections





Flow quality (limit)





Business type





Catchment area





Onsite basic storage





B.3
Key Issues
Participants were asked to identify the key issues in working with existing drainage data. The
following table lists those which participants identified as being the most significant and those
which would need to be overcome for an integrated dataset to be successful. Headings have been
added to group issues according to common themes.
Table 5
Table 4
Table 3
Issues
Table 2
Table 17 Key Issues Faced by Participants in Working with Existing Drainage Data
Table 1

Lack of Data Availability





Availability of information – digital/hardcopy/any other format. Transfer
of data – historical data





Limited data availability in some areas (or none) or incorrect (non GIS
format)





Data are often not spatial





Usability of Available Data (Fitness for Purpose)





Reliability/ accuracy/integrity/ completeness





Positional accuracy & std (station of formats GIS)





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Table 5
Table 4
Table 3
Table 1
Issues
Table 2
Preliminary Review for a Drainage Dataset – Report & Recommendations
Consistency of dataset due to staff issues





Lack of performance data i.e. flooding





Metadata/data dictionaries





Data quality/disclaimers definition





Data Integration: Data Formats





Data format – conversions (internal not an issue)





Lack of easily assimilated update data both internal and external





Spatial & analysis datasets (maintaining both)





Exchange of data – file format





Data/systems integration within organisation





Data Integration: Inconsistent Data Model/Specifications





Compatibility – attributes diff custodians





Connectivity – sharing dataset





Definitions of Catchments





Generalisation of attribution





Attributes/need but custodian low importance to item





Data acquisition – compatible data structure/format – interoperability





Format/attribute incompatibility





Lack of std presentation





Support for Data Capture & Maintenance





Funding – relationship with other organisations (MOU’s)





Funding & resources





Mainstreaming/communicating importance





Recognition of resource requirements for maintenance





Minimal strategic planning





Governance & Data Accessibility





Data access





Exchange of data with joining Authority Utility





Accessibility (not recorded, not compiled across LGA’s not current)





Access to maintenance records





Custodianship





B.4
Solutions
Participants were asked to suggest solutions to overcome the most significant barriers. Responses
are listed below.
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Table 5
Table 4
Table 1
Solutions
Table 3
Table 18 Suggested Solutions
Table 2

Implement a Common Data Model/ Specification





Adopt common standards by all (d-Spec), liaise with IPWEA





Development of an industry std in terms of the data format specifications





Agreement of std between custodians & users





Capture physical data to common std





Hierarchical views fit for purpose datasets





Data consistency enforced by common system (topology, domains,
mandatory fields)





Implement Coordinated Governance & Accessibility





Willingness to share data – framework for what attributes & purpose
(log-in) security





Adopting universal governance rules i.e. handover of assets on
completion of points





LGA – GIS Availability





Central coordination





Central funding (Roman roads)







Coordination /custodianship at WALIS/State level – data entry,
maintenance at LGA level



Use SLIP EM as delivery mechanism (accessibility)





Source External Funding





Funding – various sources – involve catchment groups to develop
drainage networks using external funding sources





WALIS to manage a government funded project to capture D-spec





Potential backing (on environmental, EM risk management grounds)





Tie funding incentives to maintenance/data capture – National Water
Initiative





Existing infrastructure needs to collected possibly with State assisted
funding





Catchment groups – educating community, decision makers





Secure Internal Funding





Maintenance/upgrading/effectiveness costs





Needs analysis – level of problem





Feasibility of upgrade of data vs. recollection of data





Building in new innovations – R & D





Elevate importance of drainage data





B.5
Key Benefits
Participants were asked to identify the key benefits of an integrated dataset (assuming that an
integrated dataset was available). The intent of this question was to assess how important the
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Preliminary Review for a Drainage Dataset – Report & Recommendations
initiative was likely to be to each organisation. The following table presents the responses with
headings added to group common themes.

Table 19 Key Benefits
Tactical/ Strategic Planning


Table 5
Table 4
Table 3
Table 2
Table 1
Benefits




Planning new drainage developments




Predict flood impact





Environmental sustainability





More accurate output from models – capital planning





Greater scope for strategic planning in terms of availability of dataset





Budgeting





Data drives knowledge – informed decision making





Improved Asset Management/ Maintenance





Prevention of local flooding/reduced risk individual councils to maintain
asset data set AA S27 (more accurate)





Asset management





Safer communities





Support for Cross-Boundary Initiatives





More informative information for catchment modelling





Integration of adjacent data





Regional management/environmental planning





Remove cross boundary issues





Perth urban water balance study





Provision of information across boundaries – including to developers





Emergency & Incident Management





Emergency Management





Increased ability to aid emergency managers





Immediate pollution response





Incident management





Reliable/accessible data – to EM groups





Water Quality Management





Control of pollution





Model impact of stormwater on eco systems





Show support for environment





Better water quality. Improve ecological health





Water quality, budgets volumes





Compliance for health benefits





Operational Efficiencies





Uniformity





SINCLAIR KNIGHT MERZ
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Table 5
Table 4
Table 3
Table 2
Table 1
Benefits
Level of confidence of information





Improved access to information – quick





Potential efficiencies – removal of possible redundancies





Operational/field efficiency





Reduction of cost of data acquisition/maintenance, reduced data
duplication





Portability of skills/ mobile resources










Some groups provided specific comments on how important the initiative was likely to be to
organisations. This was also briefly discussed at the end of the workshop. Comments included the
following:

A ‘nice to have’ and a form of insurance;

Not a vote winner for Councillors (a funding issue);

When things go wrong then important (if there is a significant incident then the information
would be seen as being important);


Relatively small benefit for well developed LGA’s drainage data systems;
Likely to be a greater benefit to State government in relation to initiatives which cross LGA
boundaries.
SINCLAIR KNIGHT MERZ
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Appendix C Stocktake of Existing Datasets
C.1
Features
The following table shows the features currently stored by the 18 LGAs which have a digital dataset
of stormwater drainage (out of a total of 20 LGAs which responded to the survey).

Table 20 Features Stored by the LGAs With a Digital Drainage Dataset
Features
Percentage of LGAs
Number of
LGAs
Data Structure – Features
Pipe sections
100%
18
Pits/ access points
89%
16
Property connections
33%
6
Underground conduit pits
33%
6
Underground conduits
22%
4
Sump boundaries/ sumps
17%
3
Design boundary extent
11%
2
Access chambers
6%
1
Catchments
6%
1
Easements
6%
1
Gross pollutant traps
6%
1
Gullies
6%
1
Problems with matching to existing data
6%
1
SEP’s
6%
1
Soakwells
6%
1
sump outlets
6%
1
Table drains
6%
1
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Preliminary Review for a Drainage Dataset – Report & Recommendations
C.2
Attributes
The following table shows the attributes currently stored by the 18 LGAs which have a digital
dataset of stormwater drainage (out of a total of 20 LGAs which responded to the survey).

Table 21 Attributes Stored by the LGAs With a Digital Drainage Dataset
Attributes
Percentage of
LGAs
Number of
LGAs
Pipe Attributes
Diameter
89%
16
Material
89%
16
Length
78%
14
Pipe number or identifier
78%
14
Invert level (upstream and/or downstream)
72%
13
Street name
61%
11
Construction date
44%
8
Catchment number/ id
22%
4
Plan number
22%
4
Condition
17%
3
Subdivision name
17%
3
Accumulated depreciation
11%
2
Item/ design life
11%
2
Road number/ road id
11%
2
Written down value
11%
2
% of expected life
6%
1
Adequacy rating
6%
1
Construction company
6%
1
Current cost of replacement
6%
1
Date Inspected
6%
1
Design company
6%
1
De-watering factors
6%
1
Item type
6%
1
Land type
6%
1
Linked to asset valuation
6%
1
Pipe grade
6%
1
Pit Upstream / Downstream & id
6%
1
Soil type
6%
1
Stage number
6%
1
Pit number or identifier
78%
14
Lid type
56%
10
Cover level/ finished surface level
50%
9
Pit Attributes
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Attributes
Percentage of
LGAs
Number of
LGAs
Street name
50%
9
Construction date
44%
8
Depth
44%
8
Side length
28%
5
Side width
28%
5
Pit type
22%
4
Litter traps
17%
3
Pit condition
17%
3
Plan number
17%
3
Accumulated depreciation
11%
2
Catchment number/ id
11%
2
Design life
11%
2
Subdivision name
11%
2
Written down value
11%
2
% of expected life
6%
1
Collected by
6%
1
Construction material
6%
1
Depth to invert
6%
1
Design company
6%
1
Land type
6%
1
Lid condition
6%
1
Lid level
6%
1
Reduced level
6%
1
Replacement cost
6%
1
Road number/ road id
6%
1
Soil type
6%
1
Special Features and Photo Link
6%
1
Street name
22%
4
Diameter
17%
3
Material
17%
3
Property connection number or identifier
17%
3
Construction date
11%
2
Depth
11%
2
Plan number
6%
1
Conduit number or identifier
11%
2
Diameter
11%
2
Length
11%
2
Property Connection Attributes
Underground Conduit Attributes
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Preliminary Review for a Drainage Dataset – Report & Recommendations
Attributes
Percentage of
LGAs
Number of
LGAs
Material
11%
2
Street name
11%
2
% of expected life
6%
1
Accumulated depreciation
6%
1
Adequacy rating
6%
1
Catchment id
6%
1
Condition
6%
1
Construction date
6%
1
Design life
6%
1
Land type
6%
1
Replacement cost
6%
1
Soil type
6%
1
Subdivision name
6%
1
Type
6%
1
Written down value
6%
1
Catchment id
11%
2
Conduit pit number or identifier
11%
2
Depth
11%
2
Material
11%
2
Street name
11%
2
% of expected life
6%
1
Accumulated depreciation
6%
1
Adequacy rating
6%
1
Construction date
6%
1
Depth to invert
6%
1
Design life
6%
1
Land type
6%
1
Pit type
6%
1
Reduced level
6%
1
Replacement cost
6%
1
Soil type
6%
1
Subdivision name
6%
1
Written down value
6%
1
Underground Conduit Pit Attributes
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