Seymour Township and Goulburn River Environs Flood Sub-Plan
Orientation
This page analyses the Seymour Township and Goulburn River Environs Flood Sub-Plan as a Mitchell Shire Council flood-risk, land-use, and emergency-management instrument.
The source document is an October 2002 sub-plan to council’s Seymour Municipal Emergency Management Plan. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The extracted PDF metadata records the downloaded source as a Mitchell Shire Council document. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The document itself carries CT Management Group Pty Ltd page footers dated June 2000, so the corpus shows both a document date and a preparation/footer date. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan covers Seymour, the Goulburn River environs, and the catchment reach from Lake Eildon to Seymour. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Its planning significance is not just emergency response.
It records flood thresholds, inundation mapping intent, land-use controls, dwelling floor-level expectations, and floodplain-management referral roles. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The page should be read beside mitchell-open-space-strategy, climate-emergency-action-plan-2024, parks-open-space-asset-management-plan, and drainage-asset-management-plan because riverine flood risk affects open space, assets, resilience planning, and drainage operations.
Source Basis
Two extracted text files were identified in the Mitchell Shire Council corpus.
The hyphenated extract is seymour-township-and-goulburn-river-environs-flood-sub-plan.txt.
The underscored extract is seymour_township_and_goulburn_river_environs_flood_sub-plan.txt.
Both extracts point to the same downloaded PDF source path in the harvester metadata. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The hyphenated extract has 807 lines in the local corpus.
The underscored extract has 803 lines in the local corpus.
The small line-count difference appears to be extraction formatting rather than evidence of a separate plan version.
This analysis relies on the hyphenated extract as the primary readable source.
The plan says it has three attached operational documents: Flood Response Guidelines, Flood Operations Manual, and Flood Information Providers Manual. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Those attachments are not present in the matched source files.
The absence matters because the sub-plan repeatedly refers operational detail to those attached documents. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The gaps file records those missing attachments as material source gaps.
Governance Role
The plan is expressly a sub-plan to the Seymour Municipal Emergency Management Plan. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Its aim is to minimise danger to life and damage to property from flood emergencies in the covered area. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Its objective is to record agreed flood-specific arrangements and main roles for prevention, preparedness, response, and recovery. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan prioritises protection of life, essential services, public utilities, property, and personal safety within flood areas. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan acknowledges the Department of Natural Resources and Environment and the Goulburn-Broken Catchment Management Authority as management authorities for the state’s riverine assets. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At regional level, the Goulburn Broken Catchment Management Authority is identified as responsible for floodplain management, planning, and advice to councils, state authorities, and the community. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At state level, the Department of Natural Resources and Environment Floodplain Management Unit is identified as responsible for floodplain management. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan makes VICSES the designated control agency for flood response in Mitchell Shire Council. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
That control-agency allocation means council’s planning role is mostly preparedness, local alerting, resource coordination, road closures, welfare centres, recovery, and land-use controls.
The municipal flood sub-committee is to include Mitchell Shire Council, the Municipal Emergency Resource Officer, Flood Warning Officer, Recovery Manager, VICSES, Goulburn Broken Catchment Management Authority, Goulburn-Murray Water, Victoria Police, CFA, and other agencies as required. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The committee is required to meet at least once per year. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The MERO is responsible for calling and conducting the annual meeting and updating the plan. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
That annual-review requirement is a monitoring signal: if no later plan exists, the 2002 document is very likely obsolete against its own governance expectation.
Catchment And Hazard Setting
The upstream Goulburn River catchment at Seymour is approximately 8,600 square kilometres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan lists Sunday Creek, Whiteheads Creek, King Parrot Creek, the Yea and Murrindindi Rivers, Home Creek, and the Acheron and Rubicon Rivers as part of the river network upstream of Seymour. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It identifies the Delatite, Howqua, Jamieson, and Big Rivers as headwater contributors flowing into Lake Eildon. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
This makes Seymour a downstream receiver of multiple tributary systems, not just a township beside a single river channel.
The plan states that Seymour’s Goulburn River environs begin to experience localised flooding along the river frontage between Kings Park and the old Hume Highway at minor Goulburn River flood levels. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It also records that rural roads and rural properties can experience localised flooding due to heavy rainfall throughout the year. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The local hazard is therefore a combination of riverine flooding, tributary response, stormwater backup, and rural access disruption.
The plan says a flood inundation mapping study was conducted in Seymour to create maps for the flood warning system and statutory land-use planning controls in the Mitchell Planning Scheme. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
That sentence is one of the strongest planning links in the document.
It means the warning maps were intended to support both emergency operations and planning-scheme flood controls.
Appendix 2 is described as mapping the area subject to inundation in a major flood representing a 1 in 100 year flood frequency. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan equates the 1% event with a one-in-one-hundred chance of occurring in any year. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For development assessment, this 1% framing is the practical risk benchmark in the sub-plan.
Flood History Signals
The plan lists notable twentieth-century Goulburn River floodplain floods in 1916, 1917, 1934, 1952, 1973, 1974, 1975, and 1993. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It identifies the 1916 and 1917 events as the largest floods in Seymour’s history. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It notes that evidence on impacts and costs from the 1916 flood is scant. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The 1916 and 1917 floods are said to have influenced the business centre’s concentration along Station Street rather than the original Emily Street location. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
This is a land-use legacy signal.
The floodplain did not merely damage assets; it altered the geography of commercial concentration in Seymour.
The 1973 flood is identified as Seymour’s most severe flash flood from Whiteheads Creek and resulted in one drowning. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
That historical fatality supports the plan’s emphasis on life safety over property protection.
The May 1974 flood peaked at 7.64 metres on the Seymour Gauge, equal to 137.884 metres AHD. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The 1974 peak was 0.64 metres above the major flood level on the Seymour Gauge. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The 1974 event is given an approximate 30-year ARI. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The September 1975 flood peaked at 7.12 metres on the Seymour Gauge, equal to 137.364 metres AHD. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The 1975 peak was 0.12 metres above major flood level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The 1975 event is given an approximate 15-year ARI. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Both the 1974 and 1975 floods were predominantly from the Sunday Creek catchment. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
That attribution matters because Sunday Creek can drive major Seymour outcomes even when upstream Lake Eildon attenuates Goulburn flows.
The October 1993 town flooding was caused by Goulburn River floodwater. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The October 1993 river peak is recorded at around 6.66 metres, equal to 136.904 metres AHD, below major flood category. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The 1993 flood inundated the Goulburn River Caravan Park. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The 1993 flood disrupted traffic, with some roads reduced to one lane width. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan separately records a 6.11 metre Goulburn River peak on 6 October 1993, also below major flood category at the Seymour gauge. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The two 1993 gauge references should be treated carefully because the plan mentions both 6.66 metres and 6.11 metres.
The difference may reflect separate September and October peaks or extraction/context ambiguity.
The gaps file flags this for verification against the cited 1993 Spring Flood Summary Report.
Lake Eildon Dependency
Lake Eildon is described as providing significant attenuation of Goulburn River flows. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the October 1993 flood, Lake Eildon reduced peak discharge from 170,000 ML/d inflow to 46,630 ML/d peak outflow. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
That is a reduction of 123,370 ML/d between inflow and outflow as reported in the plan.
The outflow was about 27.4% of the inflow using the plan’s figures.
The implied attenuation was about 72.6% of peak inflow.
The plan says this reduction is documented in the 1993 Spring Flood Summary Report for the Department of Conservation and Environment. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
During the October 1993 event, Lake Eildon rose 0.59 metres above full supply level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan warns that a dam-safety review may find that level of surcharging inappropriate. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
If surcharge is constrained in future, the plan says the flood-mitigation benefit may reduce when the reservoir is full. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
This is a critical planning risk.
Land-use assumptions based on the 1993 outcome may understate future exposure if reservoir operating constraints change.
The mechanism is direct: less upstream storage or surcharge capacity would transmit higher downstream peaks toward Seymour.
This dependency should inform flood overlay reviews, emergency access standards, caravan park approvals, and any redevelopment close to the Goulburn River frontage.
Gauge Thresholds
The plan provides indicative gauge heights for the Goulburn River at Lake Eildon downstream, Trawool, and Seymour. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It explicitly says the heights are indicative only and based on local effects, site topography, limited observations, and local knowledge. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It also says more reliable gauge heights would be developed after one or more events occurred. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River at Seymour, minor flood level is 4.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River at Seymour, moderate flood level is 5.2 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River at Seymour, major flood level is 7.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River at Trawool, minor flood level is 4.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River at Trawool, moderate flood level is 5.6 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River at Trawool, major flood level is 7.5 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River downstream of Lake Eildon, minor flood level is 3.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River downstream of Lake Eildon, moderate flood level is 4.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For the Goulburn River downstream of Lake Eildon, major flood level is 5.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For Sunday Creek at Tallarook, minor flood level is 3.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For Sunday Creek at Tallarook, moderate flood level is 3.5 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For Sunday Creek at Tallarook, major flood level is 4.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan says flood levels for these locations required confirmation by relevant authorities. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
This is a major evidence limitation for planning reliance.
Any current decision should confirm present Bureau of Meteorology, Goulburn Broken Catchment Management Authority, and Goulburn-Murray Water gauge datums before using these thresholds.
Seymour Local Trigger Points
The flood information card identifies 4.00 metres at the Seymour gauge as the minor flood level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 4.00 metres, the Goulburn Caravan Park commences flooding. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 4.00 metres, Mitchell Shire is to advise the Goulburn Caravan Park when the river is rising to that level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The card links that warning to the Ghin Ghin gauge. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The card identifies 5.2 metres at the Seymour gauge as the moderate flood level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 5.2 metres, Sunday Creek flows are noted as causing rapid river rise. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The card identifies 6.6 metres as a flood inundation map trigger. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 6.6 metres, rising river floods Tierney, High, and Wallis Streets and the Winery Area. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 6.6 metres, stormwater backup flow to Emily Street is identified. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 6.6 metres, Kings Park flooding is recorded with a 1993 reference. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The action column says Mitchell Shire is to action the flood alert process and FM88 when the river is rising to 6.3 metres, based on the flood study. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
This creates a 0.3 metre operational lead between the 6.3 metre alert action and the 6.6 metre mapped inundation trigger.
The card identifies 7.0 metres as the major flood level at Seymour. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 7.0 metres, North Seymour residential and commercial area flooding is identified. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 7.0 metres, Emily Street area houses are isolated and the surrounding area inundated. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
At 7.0 metres, school bus routes begin closure on the Goulburn River frontage. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
These thresholds should be treated as development constraints as much as emergency triggers.
They indicate where evacuation, access, stormwater, and public-realm assumptions begin failing.
Warning And Communications System
The plan says a rainfall and flood data collection network was established for the Goulburn River catchment from Lake Eildon to Seymour. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The Bureau of Meteorology issues flood advice where weather patterns show flood potential. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Where the data collection network shows flooding is imminent, a flood warning is issued. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan treats flood advices and flood warnings as flood warnings for dissemination purposes. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Regional dissemination is by VICSES to municipalities, regional emergency response coordinators, local SES units, and other regional agencies. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Mitchell Shire is responsible for endeavouring to alert appropriate properties. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The alert system includes Seymour FM88 Community Radio and, where appropriate, Upper Goulburn Community Radio. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The rural alert system includes Faxstream for people who provided fax numbers. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The urban alert system includes Faxstream and a telephone alerting plan. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The phone list excludes silent numbers unless property owners provide them. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Council can change Tourist Radio FM88 signs to Municipal Emergency Radio FM88 signs during flood warnings. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Council can place warning lights on strategically located FM signs to indicate an emergency event. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Council may ask emergency service personnel and council staff to door-knock residents in flood-prone areas. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan says council will keep FM88 updated and fax updated warnings to owners who supplied fax numbers. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It lists Weather by Fax on 1800 630 100 and Flood Warnings by Fax on 1902 350 015. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
During a major flood, council may advertise and staff a flood hotline. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The communications model is visibly of its time.
Faxstream, phone lists, FM tourist radio, and sign lighting all require current validation before being relied on.
For modern planning intelligence, the important point is redundancy: radio, direct contact, signage, door knocking, and hotline capacity all compensate for failure of any one channel.
Land-Use Planning Mechanisms
The prevention section identifies policy and regulation for land use and buildings as a task for Mitchell Shire and Goulburn Broken Catchment Management Authority, with state/regional roles from NRE and DOI. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan refers to Urban Floodway Zone, Flood Overlay, and Land Subject to Inundation Overlay clauses in the planning scheme. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It identifies Goulburn Broken Catchment Management Authority as the referral authority for these flood-related planning controls. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
New subdivisions and dwellings may require potential house sites to be above the determined 1% flood level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Subdivision conditions may require selected fill to build up house sites. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Larger subdivisions may require drainage plans. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Those drainage plans may include retarding basins. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
In rural areas without flood studies, the plan says subdivision and dwelling assessment relies on site investigation and local knowledge of council officers, GBCMA, the applicant, neighbours, and others. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
This creates a weaker evidentiary base outside studied areas.
In those locations, planning risk turns on whether local knowledge is sufficiently documented and whether contemporary flood modelling exists.
The plan says advice from Goulburn Broken Catchment Management Authority should be obtained in the first instance. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Dwellings or other habitable buildings may be permitted in designated floodway areas. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Dwellings may be permitted in flood fringe areas where inundation does not exceed 500 millimetres, danger to life or health is not caused, and floor levels are 300 millimetres above the 1% AEP flood contour. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The 500 millimetre inundation depth and 300 millimetre freeboard are concrete design thresholds in the document.
Industrial and commercial buildings are to be assessed on their merits under Victorian Planning Provisions planning practice notes for flood management. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Planning approvals may be conditional on the provision and maintenance of floodways. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan says floodways must not later be restricted or obstructed by fences, buildings, or similar works. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Council cannot approve a building permit if it believes there is danger to life or health of occupants. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Residential extensions must follow GBCMA policy and practice guidelines for building extensions to existing dwellings on flood-liable land. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The planning mechanism is therefore not a simple no-build rule.
It is a layered risk-management system using mapped flood levels, referral advice, fill, drainage, retarding basins, freeboard, floodways, and permit conditions.
Flood Protection And Levees
For rural dwellings, the plan encourages landholders to construct earthen bunds around dwellings and the immediate curtilage to provide flood protection at least up to the 1% flood level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It says properly planned bunds can be drained and have drains controlled during a flood. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It also says earthen bunds are defined as works under current planning controls and may require a planning permit. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
For urban dwellings, the plan points individual property protection to the Flood Response Guidelines brochure available from council and VICSES offices. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Where an approved flood mitigation scheme exists, the responsible authority must construct, maintain, monitor, and operate the scheme. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Maintenance of an approved scheme must include protection of floodways and overflows. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Where approved levees have been constructed to an approved design flood level, maintenance is a private matter for the owner of the levee. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
During floods, levees may only be raised by sandbagging or earthworks with approval of the responsible authority and after consultation with VICSES. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan warns that strengthening or raising levees outside formal mitigation schemes may create legal liability. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It says levees can create additional afflux and further flooding to upstream properties. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It says constricting the flow path can reduce floodplain storage and increase and accelerate flows downstream. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
This makes private levee activity a development feasibility and neighbour-risk issue.
New works that appear protective for one site can transfer risk upstream or downstream.
Planning permits, enforcement, and emergency authorisation should therefore treat ad hoc levee works as a floodplain-system intervention.
Response And Recovery Implications
During flood response, council and VicRoads are responsible for barriers, signs, and road or highway closures at municipal level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Evacuation is assigned to police in consultation with VICSES and Mitchell Shire at municipal level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Welfare centre management is a Mitchell Shire responsibility, supported by VICSES. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Rescue is assigned to police and VICSES. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Advice on drainage and pumping is assigned to Mitchell Shire, with Goulburn-Murray Water at regional level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
General assistance such as sandbagging, lifting furniture, and safe areas is subject to available resources from local SES units and Mitchell Shire. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Media releases are assigned to VICSES, police, and Mitchell Shire. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The Municipal Emergency Coordination Centre can be opened at the request of the MERO, VICSES Controller, or Municipal Emergency Response Coordinator. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Primary support agencies include Mitchell Shire, Victoria Police, Bureau of Meteorology, Goulburn Broken Catchment Management Authority, and CFA. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
All agencies named in the Municipal Emergency Management Plan may be asked for assistance. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Supporting agencies must advise VICSES of relevant intelligence, direct requests for assistance, and accept VICSES direction. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Evacuation need is to be identified by VICSES, police, and the MERO. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Police and VICSES implement evacuations, assisted by other agencies case by case. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Self-evacuation is not precluded. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Recovery activities commence when people, property, or the community are affected by flooding. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Temporary accommodation is assigned to Mitchell Shire at municipal level and the Department of Human Services at regional level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Emergency grants are assigned to the Department of Human Services. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Council may establish a one-stop shop for insurance, financial grants, personal needs, clean-up information, structural-damage advice, counselling, and flood information updates. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
These recovery responsibilities imply that council’s floodplain planning exposure is not limited to assets it owns.
When private dwellings, caravan parks, shops, schools, or roads fail in a flood, council still carries coordination and recovery workload.
Caravan Parks And Transient Populations
The plan singles out caravan parks as particularly vulnerable to flooding. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It says council should nominate alternative sites for caravan park residents, taking security, toilets, showers, and electricity needs into account. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It identifies difficulty notifying owners of on-site caravans who do not live on-site as a major problem. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
During the 1993 floods, a number of caravan owners with on-site vans lived in Melbourne or elsewhere. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan says owners should be compelled to provide caravan park managers with current contact numbers and authorisation to move caravans at cost if time permits after resident evacuation. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The flood operations checklist separately lists caravan parks, hospitals, aged homes, transient populations, disabled people, tourists, campers, and schools as groups or facilities to notify. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
This is an approvals and compliance issue for accommodation uses near the Goulburn River.
Planning permits for caravan parks and similar uses need emergency contact systems, relocation arrangements, power and sanitation continuity, and authority for movable assets.
Asset And Access Implications
The flood operations checklist includes reconnaissance of levees, bridges, roads, and properties. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It includes road closure tasks for signage, barricades, warning lights, diversions, and notification to emergency services, the public, and media. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It includes asset protection for essential services and council assets. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It includes municipal sand and sandbag policy and stock. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It includes relief-centre tasks for feeding, registration, needs, personnel, relocation, bedding, reunion, return, and recovery. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It includes livestock needs, feed, milking, and transport. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It includes essential commodities such as food, water, power, gas, and sewerage. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
It includes loaders and trucks as equipment needs. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The checklist makes the infrastructure mechanism clear.
Flood exposure converts rapidly into road access, welfare, food, utilities, equipment, and livestock-support problems.
For development feasibility, this means access routes and service continuity should be assessed as part of floodplain land-use decisions, not left wholly to emergency response.
Development Feasibility Implications
Sites below or near the 1% flood level face likely referral scrutiny from Goulburn Broken Catchment Management Authority. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Residential proposals may need floor levels 300 millimetres above the 1% AEP flood contour. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Flood fringe dwellings may be constrained where inundation exceeds 500 millimetres or danger to life or health is present. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Subdivisions may need fill, drainage plans, and retarding basins. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Approvals may require floodways that remain unobstructed over time. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Rural dwellings may need bunding up to the 1% flood level, but bunds themselves may require permits. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Levee or bund works can transfer flood risk through afflux, reduced storage, or accelerated downstream flows. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Caravan park and transient accommodation proposals face heightened warning, evacuation, contact, and relocation constraints. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Commercial and industrial proposals are not exempt; the plan says they are assessed on merits under flood-management planning practice notes. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Stormwater backup to Emily Street at the 6.6 metre Seymour trigger indicates that river flooding can interact with urban drainage. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
That interaction should be considered when assessing infill, road levels, drainage upgrades, and public-realm works in Seymour.
Open Space And River Corridor Implications
Kings Park is named as part of the river frontage area where localised flooding begins at minor flood levels. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Kings Park flooding is also identified on the Seymour flood information card with a 1993 reference. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan’s floodway warnings imply that open-space corridors along the river are not merely recreational land.
They also provide conveyance and storage functions that should not be blocked by fences, buildings, or ad hoc levees. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The open-space planning implication is that riverfront parks, flood-prone reserves, and low-lying corridors should be managed for recoverable assets, evacuation visibility, and flood conveyance.
The sub-plan does not quantify park asset losses or open-space recovery costs.
That absence should be cross-checked against parks-open-space-asset-management-plan and mitchell-open-space-strategy.
Contested And Unresolved Issues
The plan relies on a 2002 emergency-management framework and June 2000 operational content. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Agency names, communications channels, phone and fax arrangements, and planning scheme terminology may have changed since publication.
The plan says flood gauge levels need confirmation by relevant authorities. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan says local datum levels for minor, moderate, and major flood levels would be established after installation and commissioning of the data collection network. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The flood information cards list Gauge Zero AHD as unknown or to be determined. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan references missing Flood Response Guidelines, Flood Operations Manual, Flood Information Providers Manual, Flood Alert Operations Procedures, and Flood Operations Procedures. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The plan references the 1993 Spring Flood Summary Report but that report is not among the matched source files. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The Appendix 2 mapped flood plans are represented in the text as an insertion placeholder rather than readable map geometry. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The Appendix 6 Business Unit Emergency Management Agreement is represented as “Mitchell Shire to attach” rather than included content. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
These omissions materially affect planning interpretation.
Without the map geometry and updated gauge datums, the document should be treated as historical intelligence and a source of mechanisms, not as a current statutory flood level dataset.
Timeline And Monitoring Signals
1916 is recorded as the largest flood on record for Seymour. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
1917 is recorded with 1916 as one of Seymour’s largest historical floods. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
1934, 1952, 1973, 1974, 1975, and 1993 are listed as notable flood years. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
1973 is recorded as a fatal Whiteheads Creek flash flood. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
May 1974 peaked at 7.64 metres on the Seymour Gauge. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
September 1975 peaked at 7.12 metres on the Seymour Gauge. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
October 1993 caused caravan park inundation and traffic disruption below major flood level. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
October 2002 is the document date shown on the title page. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
A current review should look for later municipal flood emergency plans, flood studies, revised flood intelligence cards, updated flood overlays, and post-2022 flood lessons.
Annual flood sub-committee meetings are required by the plan and are a direct governance monitoring signal. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Post-operational debriefs after significant flood events are also required and should consider vulnerable areas, mitigation, warnings, monitoring, command, communications, public information, and plan updates. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
Planning Intelligence Bottom Line
The sub-plan is old, but it is analytically valuable because it ties Seymour flood behaviour to concrete land-use thresholds.
Its most important current-use facts are the 8,600 square kilometre upstream catchment, the 1% flood benchmark, the 300 millimetre freeboard criterion, the 500 millimetre flood-fringe depth criterion, and the Seymour gauge trigger sequence from 4.0 metres to 7.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The strongest development-risk areas named in the plan are the Goulburn Caravan Park at 4.0 metres, Tierney, High, Wallis Streets and the Winery Area at 6.6 metres, Emily Street stormwater backup at 6.6 metres, and North Seymour residential and commercial flooding at 7.0 metres. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The strongest system dependency is Lake Eildon, which the plan says reduced October 1993 peak inflow from 170,000 ML/d to 46,630 ML/d outflow. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
That dependency is not stable enough to rely on without checking dam-safety operating rules, because the plan itself warns that future surcharge constraints could reduce flood-mitigation benefit. (Source: seymour-township-and-goulburn-river-environs-flood-sub-plan.txt)
The strongest governance risk is currency.
The plan’s own annual-review requirement, unconfirmed gauge levels, missing attachments, fax-based warnings, and unknown AHD gauge zero values all point to the need for current flood intelligence before decisions are made.
For Mitchell Shire Council, the practical policy implication is to keep Seymour floodplain decisions tied to contemporary Goulburn Broken Catchment Management Authority advice, current flood overlays, emergency access standards, and post-event review evidence.