The concept design stage involves selecting the type, location and approximate size of stormwater treatments. It focuses on understanding site opportunities and constraints, identifying a preferred treatment type and design configuration, and confirming there is adequate land available.
At the end of this stage, your council and/or Melbourne Water should agree on the design objectives and indicative stormwater treatment footprint, subject to the functional design.
The concept design usually includes the following design objectives:
Melbourne Water, councils and landowners may have additional objectives for the site.
Concept design package
The concept design package contains drawings, calculations and models, and must be prepared by a concept designer with skills in engineering, plant ecology and landscape architecture. The package must show that the:
Developers designing wetlands that will be handed over to Melbourne Water for operation and maintenance must use the Constructed Wetlands Design Manual.
The following requirements are typical for concept design submissions. Depending on the scale and type of treatment, some or all of these may be relevant for the design and required by the approving authority.
These requirements can also be used or adapted to prepare a brief for a project tender or a list of requirements for a development application or planning permit.
A statement listing:
- any parts or behaviour of the design that do not conform with requirements of the relevant authorities
- justification for how the proposed alternative approach achieves similar or better outcomes
- pollutant reductions comply with current urban stormwater best practice environmental management guidelines
- safety outcomes
- maintenance costs
- sustainability and robustness
Concept design report that is technically reviewed and undersigned by the designer
The concept design report should identify:
- the purpose, objectives and overall operation of the treatment or treatments
- the development or project location
- the upstream and downstream drainage catchment, and receiving waterway
- the overall stormwater management strategy including all treatment systems for the site
- treatments that will be integrated within retarding basins or form part of a stormwater harvesting system.
- how gross pollutants will be managed
- whether treatments are intended to be ephemeral or contain a permanent pool of water
- MUSIC models (not screen shots or summary report) including justification of key model inputs in accordance with MUSIC guidelines
- MUSIC Auditor report and Wetland Analysis Tool report (where applicable) with justification of parameters outside guideline or recommended ranges.
- a summary of site characteristics and constraints including:
- flora and fauna including identification of any species of significance listed under the Flora and Fauna Guarantee Act and Environmental Protection and Biodiversity Conservation Act
- geology and soils of the site and catchment
- if and how often the treatment site is likely to be inundated by flows from a catchment other than the one it is treating, such as overflow from an adjacent waterway
- relevant cultural heritage considerations
- existing or proposed services or assets
|Overall plan drawings
This plan should show:
- catchment boundaries for each treatment system and location of receiving waterways
- the location and indicative footprint of all existing and planned treatment systems, natural and constructed waterways and relevant retarding basins
Plan of each proposed treatment:
- indicative footprint (allowing for batter slopes and access)
- relevant details contained in the checklist overlayed on site survey and constraints (with labelled contours) or a recent aerial photograph
- indicative cross section and long section with key features and levels shown
Assessing concept design
When reviewing a design, check that all of the design objectives have been addressed. Checklists are available to help guide you through a design assessment: