title: Ballarat North PSP Drainage, IWM and Flood Constraints council: ballarat state: vic category: growth-area classification: MAJOR status: in-progress last_compiled: 2026-05-31 source_docs:

Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf
Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-2-of-2.pdf
Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf

Ballarat North PSP Drainage, IWM and Flood Constraints

Ballarat North is a drainage-led PSP problem because Burrumbeet Creek, the unnamed eastern tributary, floodplain storage, retarding-basin land take, wetland treatment areas, and stormwater harvesting all have to be resolved before the PSP land budget and DCP costing can be settled. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.1) The 2025 SMEC proof-of-concept materially advances the 2024 Arup IWM work by replacing six early basin concepts across the core-plus-expanded area with a core-area drainage strategy built around five combined wetland-retarding basin systems, one constructed waterway diversion, major culverts, and Burrumbeet Creek flood-impact modelling. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.56) (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.40-50)

Background

The Arup IWM and drainage assessment was prepared for the Victorian Planning Authority in July 2024 to provide concept-level guidance for the Ballarat North Precinct Structure Plan. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.11) Arup assessed an 832 ha study area comprising a 567 ha Core Area and a 265 ha Expanded Area, with the Core Area already rezoned Urban Growth Zone and the Expanded Area still subject to the PSP inclusion decision. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.12) SMEC was then engaged by the VPA to refine the Arup drainage strategy, prepare proof-of-concept functional design inputs, inform the PSP land budget, and support DCP costing for drainage infrastructure. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.1, 4-5)

The simplest way to understand the system is that the growth area is like a bathtub draining toward Burrumbeet Creek: the PSP can add houses, roads and schools only if the new hard surfaces do not pour water into the creek faster, dirtier, or in a way that worsens flood levels for land downstream. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.35, 49) The main planning mechanism is therefore storage, treatment and controlled release: wetlands clean runoff, retarding basins slow peak flows, roads and culverts carry overflow, and the creek corridor must be stabilised because urban runoff can worsen erosion even when peak flows are retarded. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.35, 51-53, 58-59)

Analysis

Flood Extent as the First Land-Budget Constraint

The PSP is constrained by the Burrumbeet Creek floodplain because the flood extent defines the development exclusion zone. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.60) SMEC records that the current Flood Overlay and Land Subject to Inundation Overlay are based on Water Technology 2013 modelling, and GHCMA advised VPA that the available 1% AEP Burrumbeet Creek flood extents are out of date. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.28-29, 60) The under-the-hood issue is not just that an old map exists; it is that the old model predates later catchment changes, updated hydrological practice, revised design rainfall information, and 2024 climate-change guidance. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.28-30, 61)

Arup used 1% AEP plus climate-change TUFLOW outputs supplied by GHCMA and recommended that all development and detention basins be located outside that flood extent. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.54, 60) SMEC then adopted a more explicit interim approach for the PSP: the 2100 horizon, 4.5 degrees Celsius global temperature increase, and GHCMA guideline settings were used to model future-climate flood behaviour. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.38-39, 61-62) SMEC reports that its interim conservative Scenario 3 flood extent was accepted in principle by GHCMA subject to later refinement, allowing PSP preparation to continue while the larger Burrumbeet Creek flood-study update remains unresolved. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.30)

This has a direct cause-and-effect consequence for the PSP: land cannot be treated as developable until the adopted flood line, fill strategy, storage offset and hydraulic impacts are resolved. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.60, 66-70) SMEC found that the developed-condition flood level in Burrumbeet Creek is lower by up to 0.3 m in some locations, while about 30 mm of increase occurs upstream of Midland Highway because of culvert and waterway constriction, with further refinement required in functional design to avoid flood increases. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.70) The proof-of-concept therefore supports feasibility, but it does not remove the need for detailed hydraulic design, 3D modelling, shear-stress assessment, and wetland inundation-frequency checks. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.71)

From Arup Concept Basins to SMEC Core-Area Drainage Assets

Arup sized six detention basins for the 2024 concept, with combined storage of 193,440 m3 and combined basin area of 180,300 m2, or about 18.03 ha. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.56) Arup also noted that Basins 1 and 2 were in the Expanded Area and would not be required if that area did not proceed. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.56) The appendix concept showed associated wetland areas for the six basin locations totalling about 11.0 ha, but it also warned that basin and wetland locations were subject to PSP development, land ownership and phasing. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-2-of-2.pdf, p.1)

SMEC’s 2025 strategy changes the planning mechanics. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.40-50) Instead of Arup’s six broader concept basins, SMEC identifies five core-area combined wetland-retarding basin systems: SEN, SES, CS, NWN and NWS. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.43-45, 49) The five drainage reserves total 41.6 ha, made up of SEN 5.4 ha, SES 7.6 ha, CS 11.4 ha, NWN 9.8 ha and NWS 7.4 ha. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.43-45, 49) A further 4.4 ha is identified for constructed waterway CW1, giving at least 46.0 ha of explicitly identified drainage and waterway reserve in the proof-of-concept strategy before local pipes, culverts and road-based overland flow functions are considered. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.43)

The SMEC storage volumes for the 1% AEP current-climate retarding basins total 212,900 m3, comprising SEN 24,200 m3, SES 45,400 m3, CS 50,000 m3, NWN 58,300 m3 and NWS 35,000 m3. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.49) Under the 1% AEP climate-change scenario, required storage rises to 310,700 m3 across the same five assets. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.49) The practical implication is that climate change adds about 97,800 m3, or roughly 46%, to required retarding storage compared with the current-climate 1% AEP proof-of-concept case. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.49)

Stormwater Quality and Volume Targets

The statutory water-quality floor is set by Clause 56.07 and the Best Practice Environmental Management targets: 80% Total Suspended Solids, 45% Total Phosphorus, 45% Total Nitrogen, and 70% gross pollutants or litter. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.35) SMEC’s proposed treatment train meets those targets, with modelled reductions of 80.6% TSS, 68.3% TP, 45.2% TN and 96.8% gross pollutants. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.53) The wetland surface areas used to achieve this are SEN 16,000 m2, SES 25,000 m2, CS 21,000 m2, NWS 16,000 m2, NWN-1 15,000 m2 and NWN-2 5,000 m2. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.52)

The harder target is volume management, because treating water is not the same as reducing runoff volume. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.48, 70) Arup found that wetlands alone could achieve pollutant targets but not the newer 29% harvesting and 7% infiltration targets, while 2 kL household rainwater tanks enabled the harvesting target to be met in the base case modelling. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.48) SMEC later modelled the Adaptive Plan and found that 2 kL rainwater tanks in every dwelling supply 29% of non-potable demand with about 71% reliability. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.3, 56, 59)

SMEC’s water-balance modelling estimates total PSP water demand at 3,650 kL/day, or 1,332 ML/year, with residential demand making up 87% of daily demand. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.54-55) In Scenario A with rainwater tanks, developed runoff is 1,730 ML/year compared with 698 ML/year existing runoff, producing an increase of 1,032 ML/year. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.56) SMEC estimates that 315 ML/year can be harvested from wetlands with rainwater tanks in place, equal to 31% of the runoff-volume increase. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.56-57) Without rainwater tanks, SMEC estimates 407 ML/year can be harvested from wetlands, equal to 40% of the runoff-volume increase. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.57)

The key dependency is demand and storage, not only supply. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.56-59) SMEC states that harvested-water outcomes depend on an equivalent demand being available, and that functional and detailed design must verify demand, storage and transfer infrastructure before stormwater reuse can be relied on. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.57-59) For the active open space near NWN-1 and NWS, SMEC identifies 10.5 ha requiring 52.5 ML/year of irrigation water, which would use 83% of the harvested volume from NWN-1 or 95% from NWS under the Scenario A assumptions. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.58)

IWM Portfolio Decision: Preferred Ambition Versus Deliverable Adaptive Plan

Arup’s preferred Portfolio 4 combines base-case wetlands and retarding basins, Burrumbeet Creek stabilisation, recycled water to homes, stormwater harvesting for open space irrigation, blue-green corridors, and ecological refuge for Burrumbeet Creek flora and fauna. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.8, 84-86) Arup selected Portfolio 4 because it scored strongly across IWM outcomes and was considered the most holistic portfolio overall. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.83-84) The portfolio is not self-executing, because Arup states that recycled water requires further Central Highlands Water investigation and a business case, while blue-green corridors and streetscape assets require City of Ballarat acceptance and maintenance decisions. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.84-87)

SMEC effectively treats Portfolio 4 as the strategic ambition and the Adaptive Plan as the current design basis. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.21-22, 54) The reason is mechanical: the recycled-water scheme has insufficient information for functional design, and the timing of the CHW business case is unknown. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.21-22) SMEC states that it will progress the drainage strategy based on the Adaptive Plan while future-proofing asset locations where possible for either a rainwater-tank system or a later recycled-water system. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.22)

This is the central IWM decision for the PSP. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.21-22, 54-59) If CHW proceeds with a recycled-water network, the precinct may rely more on centralised non-potable supply to meet residential and open-space non-potable demand. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.77, 81, 84) If CHW does not proceed, the PSP must fall back on 2 kL household rainwater tanks, precinct-scale wetlands, stormwater harvesting for open space, household raingardens, and bioretention or passively irrigated trees. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.85-86) The difference matters because lot-scale tanks create household-level maintenance and compliance obligations, while a recycled-water system creates CHW infrastructure, business-case and ownership dependencies. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.21-23, 36)

Burrumbeet Creek Health and Erosion Risk

Burrumbeet Creek is not only an outfall; it is also a corridor whose condition affects flood conveyance, erosion, habitat and public-realm planning. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.23-27, 58-59) SMEC observed poor waterway condition, including lack of riparian vegetation, exotic vegetation, straightened channel alignment, likely poor water quality, active erosion, vertical banks and undermined banks. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.23-25) SMEC states that future urban development is likely to increase erosion risk through increased runoff volume and longer flow durations even when peak flow rates are controlled. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.23, 25, 58)

The planning implication is that retarding peak flows is necessary but not sufficient. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.35, 58-59) Creek stabilisation, riparian revegetation, geomorphological assessment and hydro-ecological assessment are needed because development can change the shape and behaviour of the channel over repeated smaller events, not only during the design flood. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.23-25, 58-59) SMEC states that creek-corridor improvement items can be included in DCP costs because there is a nexus between future development and increased creek deformation risk, although existing instability has already been caused by current land uses. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.3, 58-59)

The Growling Grass Frog issue is a constraint with limited current design weight. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.27, 32-33) SMEC reports that WSP did not record Growling Grass Frogs, Golden Sun Moths or Striped Legless Lizards during targeted surveys, but that Growling Grass Frog could use aquatic riparian habitat under suitable high-rainfall or flood conditions because connected known habitat exists about 8.6 km upstream via Burrumbeet Creek and Slattery Creek. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.27, 32-33) SMEC does not recommend GGF ponds in the floodplain because stormwater wetlands are not optimal GGF habitat, additional GGF-specific wetlands would need space, and migration connectivity is constrained by road crossings and unsuitable intervening habitat. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.33)

Waterway Diversion and Development Interface

The most sensitive design move is CW1, the proposed realignment of the unnamed waterway near the eastern PSP boundary. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.41-43) SMEC proposes to relocate the waterway along the eastern boundary, create a constructed waterway, and use it to contain floodplain function in a narrower corridor while improving the waterway form. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.41) The constructed waterway would convey an external catchment of about 990 ha entering at the Midland Highway culverts, and the associated major culvert at Olliers Road is sized for a contributing catchment of 1,070 ha and a 1% AEP design flow of 33.7 m3/s using eight DN1950 pipes. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.43, 49)

The waterway realignment is not a settled approval question. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.41-43) SMEC records that GHCMA does not generally support waterway realignment or floodplain topography changes for large-scale development, but may consider proposals where an unequivocal advantage for waterway and floodplain health is demonstrated. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.41) SMEC also records that the WSP biodiversity assessment identifies high-value vegetation in the current alignment. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.42) This means CW1 is both a drainage asset and a statutory negotiation point with GHCMA, biodiversity inputs and future PSP layout consequences. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.41-43)

The mechanism is straightforward: filling west of the realigned waterway can make land easier to urbanise, but that fill removes floodplain storage unless offset by excavation and waterway design. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.42-43, 66-68) SMEC states that the realignment would require significant floodplain filling and excavation to offset flood storage, and that the filling cost is expected to be borne by the developer benefiting from additional developable land rather than included in DCP costs. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.43) A reserve corridor of about 60 m is required at proof-of-concept stage, but the hydraulic width and final corridor width remain subject to functional design. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.43)

Road, Culvert and Overland-Flow Dependencies

The drainage strategy depends on a major-minor system in which pipes carry frequent storm events and road reserves carry larger gap flows. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.35, 40-43) The Infrastructure Design Manual requirement used by SMEC is 20% AEP capacity for the minor residential drainage system, protection from 1% AEP major flooding, all new lots above the 1% AEP flood level, and buildings at least 300 mm above the 1% AEP flood level. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.35) In flood-prone creek-adjacent areas, SMEC also states that new lots will be set or filled to at least 600 mm above the 1% AEP creek flood level. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.46)

SMEC identifies seven major culvert groups for future roads. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.49) The largest culvert item is CUL7 at Olliers Road for the waterway, with 1,070 ha contributing catchment, 33.7 m3/s 1% AEP design flow, and eight DN1950 pipes. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.49) Other culvert groups range from two DN1200 pipes for 3.6 m3/s at CUL4 to four DN1800 pipes for 18.3 m3/s at CUL5. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.49) These culverts are not optional engineering details; they are the places where road layout, flood safety, waterway continuity and DCP costing intersect. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.49-50, 71)

Infrastructure Ownership and Governance

The drainage strategy depends on several agencies because no single body controls the whole water cycle. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.13) VPA prepares the PSP, City of Ballarat is expected to own and manage many drainage assets, GHCMA is the waterway authority for Burrumbeet Creek and constructed waterways, CHW controls recycled-water and sewer decisions, and Wadawurrung Traditional Owners have provided IWM and Healthy Country inputs. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.21-23, 32) SMEC states that future asset ownership is uncertain and should be agreed between City of Ballarat, CHW, GHCMA, VPA and Traditional Owners through agency validation. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.22-23)

CHW is a particularly important dependency because recycled water is the difference between Arup’s preferred Portfolio 4 and SMEC’s current Adaptive Plan design basis. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.84-87) Arup states that CHW should undertake water demand assessment and a business case for recycled water to service Ballarat North PSP. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.87) SMEC states that the timing of the recycled-water business case is unknown and that insufficient information prevents Portfolio 4 progressing to functional design. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.21-22)

Sewer alignment is also a local design dependency. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.40, 44-45) SMEC records that CHW indicated a future sewer alignment may clash with the proposed NWN stormwater assets, while vertical clearance may be less of an issue because the sewer is expected to be deep. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.44-45) The practical implication is that drainage and sewer corridors must be resolved together during functional design so that wetland, retarding-basin and sewer maintenance access do not conflict. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.44-45)

Current Status

As of the July 2025 SMEC report, the Ballarat North drainage work is at proof-of-concept stage and the next phase is functional design of the constructed waterway, outfall drains, major culverts, wetlands and retarding basins. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.71) SMEC recommends presenting the proof-of-concept outcomes to relevant authorities to confirm that requirements, assumptions and critical concerns have been addressed. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.71) The outcomes remain subject to change through functional design, 3D modelling, shear-stress assessment, wetland inundation-frequency analysis and updated cost estimates for the DCP. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.71)

Dependencies

Blocks: The drainage proof-of-concept blocks final certainty on the PSP land budget because WLRB reserves, CW1 reserve, flood-exclusion land and culvert requirements affect developable land and infrastructure costing. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.1, 40-50)
Blocks: The flood-impact assessment blocks final floodplain interface decisions because SMEC still identifies a 30 mm increase upstream of Midland Highway that must be refined out during functional design. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.70)
Blocked by: The recycled-water option is blocked by CHW’s water-demand assessment, business case and servicing decision. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.87) (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.21-22)
Blocked by: The final flood line is blocked by the broader Burrumbeet Creek flood-study update, although SMEC’s interim modelling has allowed PSP work to proceed. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.28-30, 60)
Blocked by: CW1 realignment is blocked by GHCMA acceptance, floodplain-storage offset design, biodiversity considerations and functional hydraulic design. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.41-43, 66-71)
Informed by: The page is informed by Arup’s July 2024 IWM and drainage assessment and SMEC’s July 2025 stormwater drainage proof-of-concept. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, p.11) (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.1)
Implements: The strategy implements Clause 56.07 water-quality targets, EPA stormwater volume guidance, Ballarat potable-water demand targets, PSP 2.0 IWM guidance and place-based IWM objectives for Ballarat North. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.35-36) (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.66-67)
Conflicts with: The current deliverable Adaptive Plan conflicts with the preferred Portfolio 4 ambition because the recycled-water scheme is not yet confirmed. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.21-22, 54)

Cross-Jurisdictional Links

Burrumbeet Creek creates a downstream link from the PSP to Miners Rest and Lake Burrumbeet because the creek and its floodplain carry flows beyond the PSP boundary. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.31, 62) SMEC reviewed the Miners Rest flood-mitigation work and found it is about 700 m downstream of the PSP core boundary, with options including levees, channel widening and regrading of Burrumbeet Creek. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.31) SMEC considers those options unlikely to significantly affect the Ballarat North PSP flood extent because there is at least two metres of fall to Miners Rest and culverts at Cummins and Victoria Street provide key hydraulic controls. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, p.31)

Central Highlands Water is a cross-agency dependency because the Ballarat North WWTP and potential recycled-water network determine whether the PSP can use Arup’s preferred recycled-water pathway or must rely on the Adaptive Plan. (Source: Ballarat-North-PSP-IWM-and-Drainage-Assessment-ARUP-V3-July-2024-Part-1-of-2.pdf, pp.35-36, 84-87) GHCMA is a cross-agency dependency because it controls waterway and floodplain acceptance for Burrumbeet Creek, the CW1 realignment, flood modelling assumptions and any in-stream works. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.28-30, 41-43, 58-59)

Gaps in This Analysis

The source set is strong for drainage concept, hydrology, IWM options and proof-of-concept asset sizing, but it is thin for statutory PSP and DCP consequences. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.1, 71) The final PSP, final land budget, DCP schedule, DCP levy rates, functional design drawings, detailed cost estimates, final authority approvals and final Burrumbeet Creek flood-study update were not provided in the manifest. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.5, 28-30, 71) Because those documents are missing, this page cannot quantify the final drainage levy per hectare, final developable-area loss by parcel, final lot-yield effect, or final owner-agency maintenance allocation. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.1, 21-23, 71)

The SMEC report lists many input reports that were not included as source documents in this manifest, including the VPA Place Based Plan, Stantec utility servicing work, WSP biodiversity assessment, RBA heritage assessment, Jacobs land capability statement, Mesh landscape and visual assessment, Tree Logic arboricultural assessment, GHD amenity assessment, Urbis economic and retail assessment, and Wadawurrung Healthy Country Plan. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.6-7) Those missing reports limit cross-checking of biodiversity, sewer, contamination, land capability, heritage, visual, open-space and activity-centre implications. (Source: Ballarat-North-PSP-Stormwater-Drainage-SMEC-July-2025.pdf, pp.32-34, 44-45)

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