Grange Planning Brain

title: Burrumbeet Creek Flood Investigation council: ballarat state: vic category: constraint classification: MAJOR status: in-progress last_compiled: 2026-05-31 source_docs:

  • expert-evidence-burrumbeet_flood_study___proposed_overlays_on_zone_map.pdf
  • page-01970-www-ballarat-vic-gov-au-news-flood-studies-be-updated-across-burrumbeet-creek-catchment.txt
  • web-research-L1-burrumbeet-2013-floodplain-resources-ghcma.txt
  • Burrumbeet2013.pdf
  • web-research-L1-burrumbeet-current-investigation-mysay.txt
  • web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt

Burrumbeet Creek Flood Investigation

The Burrumbeet Creek Flood Investigation is a flood-risk constraint program that links hydrologic modelling, emergency management, mitigation design, and statutory planning controls across Miners Rest, Invermay, Mount Rowan, Wendouree, Cardigan, Windermere, Learmonth and the Lake Burrumbeet catchment. (Source: Burrumbeet2013.pdf, p.5) The 2026-2027 update matters because it may revise the flood behaviour assumptions behind the current Floodway Overlay (FO), Land Subject to Inundation Overlay (LSIO), Municipal Flood Emergency Plan, and Miners Rest mitigation works. (Source: page-01970-www-ballarat-vic-gov-au-news-flood-studies-be-updated-across-burrumbeet-creek-catchment.txt)

Background

The 2013 investigation was commissioned by Glenelg Hopkins Catchment Management Authority in partnership with the City of Ballarat and prepared by Water Technology with Michael Cawood & Associates and Planning & Environmental Design. (Source: Burrumbeet2013.pdf, p.5) Its purpose was to define flood extent and characteristics so planning decisions could be based on mapped flood levels, hazard, warning needs, and mitigation options. (Source: Burrumbeet2013.pdf, p.5)

The 2013 study area covered the Burrumbeet Creek catchment above Lake Burrumbeet, approximately 206 square kilometres, with elevations from 377 m AHD to 607 m AHD. (Source: Burrumbeet2013.pdf, p.5) The main branch of Burrumbeet Creek is approximately 35 km long and flows west through a catchment containing Blind Creek, an unnamed Mount Hollowback/Mount Blowhard tributary, Willow Creek, Canico Creek, and township areas including Invermay, Miners Rest, Mount Rowan, Cardigan, Windermere, Burrumbeet, Blowhard and Learmonth. (Source: Burrumbeet2013.pdf, p.5)

The current investigation began after requests from residents and stakeholders to review the 2013 flood study, and the City of Ballarat states that the updated investigation is funded by the Victorian Government under the Regional Flood Risk Reduction Grant Program and is due for completion in June 2027. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt) The current update is being undertaken by Water Technology and is intended to include the stormwater network, current industry standards, riverine flooding from Burrumbeet Creek, and stormwater flooding in urban areas. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt)

Analysis

Flood Behaviour and Hazard Mechanism

The Burrumbeet Creek system behaves as a mixed rural-urban floodplain where flood response is shaped by broad floodplain storage, swamp systems, low-relief western catchment areas, and local urban drainage in and around Miners Rest and Ballarat’s northern suburbs. (Source: Burrumbeet2013.pdf, p.5) In simple terms, the creek is not just a narrow pipe carrying water from one end to the other; it is more like a shallow tray with several small channels, wetlands, roads, and low spots that can store, slow, redirect, or block floodwater. (Source: Burrumbeet2013.pdf, p.5)

The 2013 investigation modelled 20%, 10%, 5%, 2%, 1% and 0.5% AEP events, probable maximum flood, and climate-change scenarios. (Source: Burrumbeet2013.pdf, p.iii) At Miners Rest, the adopted design peak flows were 26 m3/s for 20% AEP, 38 m3/s for 10% AEP, 56 m3/s for 5% AEP, 93 m3/s for 2% AEP, 118 m3/s for 1% AEP, and 145 m3/s for 0.5% AEP. (Source: Burrumbeet2013.pdf, p.iii) At Invermay, the equivalent design peak flows were 5.4 m3/s, 9.4 m3/s, 17 m3/s, 27 m3/s, 33 m3/s and 39 m3/s, showing that Miners Rest is exposed to substantially larger modelled flows than the upper Invermay location. (Source: Burrumbeet2013.pdf, p.iii)

The January 2011 flood was estimated at 130 m3/s at the Burrumbeet Creek gauge, or about 1.6% AEP / 1 in 60 years, while the September 2010 flood was estimated at 69 m3/s, or about 6.6% AEP / 1 in 15 years. (Source: Burrumbeet2013.pdf, p.iii) This means the current statutory and emergency-management framework was heavily shaped by two recent benchmark events that exceeded the previous gauged record. (Source: Burrumbeet2013.pdf, p.7)

The January 2011 event was generated after a slow rainfall build-up, with the Burrumbeet Creek and Mt Emu Creek catchments receiving 200 mm to 300 mm of rain for the month and Ballarat Aerodrome recording 95 mm on 14 January. (Source: Burrumbeet2013.pdf, p.8) Flooding did not start until about 48 hours after rainfall commenced, but the Albert Street embankment at Miners Rest was overtopped, properties in Dundas Place, James Court and Douglas Close were extensively flooded, and roads including Midland Highway, Gillies Road, Miners Rest Road, Albert Street, Howe Street, Sunraysia Highway and Pound Hill Road were inundated. (Source: Burrumbeet2013.pdf, p.9)

Planning Controls and Permit Consequences

The Burrumbeet Creek Catchment Local Floodplain Development Plan is an incorporated document in the Ballarat Planning Scheme and applies to land affected by the LSIO and FO upstream of Lake Burrumbeet. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.1) The plan covers planning scheme maps 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 16, 17 and 18 and affects urban and rural areas of Invermay, Mount Rowan, Mitchell Park, Miners Rest, Learmonth, Windermere and Cardigan Village. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.1)

The FO and LSIO operate differently. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.2) The FO identifies floodway land required for flood conveyance and storage, generally the higher-hazard areas with deeper or faster floodwater, while the LSIO generally identifies lower-hazard floodplain fringe areas with shallower and slower flooding. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.2) The practical effect is that FO land carries a stronger presumption against new buildings and obstructive works, while LSIO land can more often be considered where floor levels, access, fill, fencing and storage impacts meet performance criteria. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.2)

For subdivision, building envelopes must be on the highest available natural ground and should not be subject to more than 300 mm depth in the 100-year ARI flood. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.4) Access to a building envelope should not cross land where 100-year ARI flood depth is more than 300 mm, and access should not be subject to depth-times-velocity hazard above 0.4 square metres per second. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.4) New or replacement dwellings must have finished floor levels at least 300 mm above the 100-year ARI flood level, which the plan defines as the nominal flood protection level. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.4)

These controls convert flood modelling into site-by-site development constraints. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.3) A planning permit application in the FO or LSIO may require AHD survey, existing and proposed ground levels, building floor levels, road and driveway levels, flood-damage reduction measures, fencing justification, and cut-and-fill volume calculations. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.3) Where an application does not comply with the local plan, it must provide a Flood Risk Report and be referred to the floodplain management authority. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.4)

Damage Exposure and Emergency Management

The 2013 damages analysis estimated average annual damage at 270,661 per year under current floodplain conditions and flows. (Source: Burrumbeet2013.pdf, p.31) For the 1% AEP event, the total damage estimate was 3,086,886, comprising building damage, infrastructure damage and indirect costs such as clean-up, relocation and emergency response. (Source: Burrumbeet2013.pdf, p.33) The 1% AEP event was estimated to flood 36 buildings above floor, 142 properties below floor, and 178 properties in total. (Source: Burrumbeet2013.pdf, p.32)

The Local Floodplain Development Plan records that the 2013 investigation identified 36 dwellings subject to over-floor flooding in 100-year ARI floods and another 23 dwellings with floors above, but within 100 mm of, the 100-year ARI flood level. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.2) This is important because the second group can move from near-miss to over-floor flooding if model assumptions change, if climate allowances increase flood levels, or if local works reduce flood storage or conveyance. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.2)

The 2013 report found that Burrumbeet Creek did not have a formal flood forecasting and warning system for communities in the catchment during the 2010-2011 events. (Source: Burrumbeet2013.pdf, p.45) It identified sparse rain and river data, lack of real-time automated gauges, limited forecast capacity, absence of flood class levels at key locations, and insufficient intelligence to translate rainfall or river height into likely flood depths and impacts. (Source: Burrumbeet2013.pdf, p.45) The planning implication is that land-use controls and mitigation works cannot be treated separately from warning systems, because even a well-mapped floodplain still carries residual risk if households and emergency services cannot receive timely flood intelligence. (Source: Burrumbeet2013.pdf, p.45)

Mitigation Options and Trade-Offs

The 2013 study assessed eight structural mitigation options: a Miners Rest levee, upstream retarding basin, Invermay railway upgrade, channel capacity increases, exotic vegetation reduction, a high-flow bypass channel south of Miners Rest, bridge capacity increases, and a flood channel north of Miners Rest. (Source: Burrumbeet2013.pdf, p.35) The top-ranked options were the Miners Rest levee with a weighted score of 18, the high-flow bypass channel south of Miners Rest with 17, the upstream retarding basin with 14.5, and the northern flood channel with no comparable weighted score. (Source: Burrumbeet2013.pdf, p.36)

The Albert Street levee was assessed as able to prevent flooding of almost 40 properties at Miners Rest. (Source: Burrumbeet2013.pdf, p.37) The same option was expected to raise flood levels locally by up to 50 mm on the creek side of the levee and affect approximately four properties with increased water levels of 20 mm to 50 mm. (Source: Burrumbeet2013.pdf, p.37) That is the core mitigation trade-off: a levee can reduce flood entry into one part of town, but it must be designed and governed so it does not transfer unacceptable residual risk to nearby land. (Source: Burrumbeet2013.pdf, p.37)

Two retarding basin locations were assessed upstream of Miners Rest, at Cummins Road and Gillies Road. (Source: Burrumbeet2013.pdf, p.38) The Cummins Road basin was estimated to reduce the 1% AEP peak flow at Miners Rest from 118 m3/s to 95 m3/s and lower flood levels at Miners Rest by up to 0.25 m. (Source: Burrumbeet2013.pdf, p.38) The Gillies Road basin was estimated to reduce the 1% AEP peak flow to 106 m3/s and lower flood levels by up to 0.1 m. (Source: Burrumbeet2013.pdf, p.38) The report nevertheless found the retarding basin option to be the least cost-effective of the detailed options because it produced only moderate damage reduction at very high cost. (Source: Burrumbeet2013.pdf, p.iv)

The high-flow bypass channel south of Miners Rest was assessed as potentially reducing the 1% AEP flow at Miners Rest from 116 m3/s to 80 m3/s and eliminating Albert Street overtopping in the 2% AEP event. (Source: Burrumbeet2013.pdf, p.41) The northern flood channel was assessed as capable of eliminating shallow inundation north of Clarke Street east in Miners Rest, but it could increase flood impacts on properties between Albert Street and Clarke Street unless combined with the Albert Street levee. (Source: Burrumbeet2013.pdf, p.41) This makes the Miners Rest mitigation problem a connected hydraulic system rather than a list of independent projects. (Source: Burrumbeet2013.pdf, p.41)

Current Update and Statutory Pathway

The City of Ballarat announced on 13 February 2026 that the Burrumbeet Creek Flood, Drainage and Mitigation Investigation would update flood mapping completed in 2013 to reflect changes in land use, recent flood events, current industry practice and updated climate guidance. (Source: page-01970-www-ballarat-vic-gov-au-news-flood-studies-be-updated-across-burrumbeet-creek-catchment.txt) The same announcement states that the investigation will assess riverine flooding from Burrumbeet Creek and stormwater flooding in urban areas. (Source: page-01970-www-ballarat-vic-gov-au-news-flood-studies-be-updated-across-burrumbeet-creek-catchment.txt)

The current catchment description used by Council is approximately 260 square kilometres, covering Invermay, Learmonth, Mount Rowan, Miners Rest, Cardigan and Windermere before terminating at Lake Burrumbeet. (Source: page-01970-www-ballarat-vic-gov-au-news-flood-studies-be-updated-across-burrumbeet-creek-catchment.txt) This differs from the 206 square kilometre study-area figure in the 2013 report, which means the current program may be using a broader catchment frame or different boundary definition than the 2013 modelling report. (Source: Burrumbeet2013.pdf, p.5) The difference is analytically important because a broader study area may capture stormwater and tributary behaviour not fully represented in the earlier statutory mapping basis. (Source: page-01970-www-ballarat-vic-gov-au-news-flood-studies-be-updated-across-burrumbeet-creek-catchment.txt)

The current project timeline identifies February to May 2026 for project introduction and initial data collection, July/August 2026 for presenting model-calibration results and gathering input on mitigation options to be modelled, December 2026 for draft planning maps and pre-feasibility mitigation results, and April 2027 for flood investigation findings and mitigation-option evaluation. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt) The first consultation events were scheduled for 25 February 2026 at Wendouree Neighbourhood Community Centre and 26 February 2026 at Miners Rest Mechanics Institute Community Hall, with both midday and late-afternoon sessions. (Source: page-01970-www-ballarat-vic-gov-au-news-flood-studies-be-updated-across-burrumbeet-creek-catchment.txt)

The MySay project page states that community flood information will be used to guide the review and upgrade of the flood study, guide the design and delivery of the parallel Miners Rest Flood Mitigation project, update flood-risk planning controls, update emergency-response flood information, and inform mitigation strategies. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt) This creates a direct pathway from community evidence to model calibration, from model calibration to planning maps, and from planning maps to future FO/LSIO amendment work in the Ballarat Planning Scheme. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt)

Current Status

As at 31 May 2026, the current Burrumbeet Creek Flood, Drainage and Mitigation Investigation is in progress and scheduled for completion in June 2027. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt) The project is in its initial data-collection stage, with later 2026 milestones expected for calibrated modelling, mitigation-option selection, draft planning maps, and pre-feasibility results. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt) The current statutory controls remain the FO, LSIO and Burrumbeet Creek Catchment Local Floodplain Development Plan unless and until updated mapping is adopted through a planning scheme amendment. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.1)

Dependencies

  • Blocks: More certain decisions on future FO/LSIO boundaries, site-specific flood levels, Miners Rest mitigation design, emergency flood intelligence updates, and development assessment in affected parts of Miners Rest, Invermay, Mount Rowan, Wendouree, Cardigan, Windermere and Learmonth depend on the updated modelling outputs. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt)
  • Blocked by: The current analysis is blocked by the absence of 2026-2027 calibrated model outputs, draft planning maps, mitigation pre-feasibility results, and final investigation findings. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt)
  • Informed by: The 2013 Water Technology flood investigation, the Burrumbeet Creek Catchment Local Floodplain Development Plan, the GHCMA floodplain resources page, community flood submissions, and the current Water Technology update inform the planning-control and mitigation pathway. (Source: Burrumbeet2013.pdf, p.5) (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.1) (Source: web-research-L1-burrumbeet-2013-floodplain-resources-ghcma.txt)
  • Implements: The investigation implements floodplain risk management through the Ballarat Planning Scheme, emergency-management planning, and flood mitigation design rather than a land-supply strategy. (Source: page-01970-www-ballarat-vic-gov-au-news-flood-studies-be-updated-across-burrumbeet-creek-catchment.txt)
  • Conflicts with: No direct policy conflict is documented in the available corpus, but any future widening of FO or LSIO controls may constrain buildings, subdivision, fill, fencing and access arrangements on affected land. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.3)

The floodplain management authority role sits with Glenelg Hopkins Catchment Management Authority, while the planning-control role sits with the City of Ballarat through the Ballarat Planning Scheme. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.1) Lake Burrumbeet can overflow to Baillie Creek, which is a tributary of the Hopkins River, creating a hydrological connection beyond the immediate urban edge of Ballarat. (Source: Burrumbeet2013.pdf, p.5) Emergency planning also depends on VICSES, police, Council and CMA coordination because the 2013 investigation recommended a staged total flood warning system with agreed agency roles, communication arrangements, field equipment funding, and ongoing flood awareness. (Source: Burrumbeet2013.pdf, p.iv)

Gaps in This Analysis

The largest gap is that the current 2026-2027 investigation has not yet produced final flood maps, calibrated modelling results, draft planning controls, or final mitigation-option evaluation in the available corpus. (Source: web-research-L1-burrumbeet-current-investigation-mysay.txt) This limits the analysis to the legacy 2013 modelling basis and the current project scope rather than the future statutory outcome. (Source: Burrumbeet2013.pdf, p.5)

The second gap is that the 2013 summary report references standalone reports for data review, methodology, flood warning, hydrology and hydraulics, mitigation options, and summary reporting, but the manifest only contains the summary report extract and not every underlying technical report. (Source: web-research-L1-burrumbeet-local-floodplain-development-plan-ghcma.txt, p.7) This limits detailed checking of model assumptions, bridge and culvert inputs, option costings, and flood-warning equipment requirements. (Source: Burrumbeet2013.pdf, p.10)

The third gap is that the proposed FO/LSIO overlay map extract is image-like and contains only the legend for proposed Flood Overlay and Land Subject to Inundation Overlay near Miners Rest, with no machine-readable parcel list, mapped area, or affected-property schedule. (Source: expert-evidence-burrumbeet_flood_study___proposed_overlays_on_zone_map.pdf) This prevents parcel-scale analysis of how the proposed overlays intersect individual properties, road corridors, building envelopes, or future subdivision potential. (Source: expert-evidence-burrumbeet_flood_study___proposed_overlays_on_zone_map.pdf)

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