title: Wallan and Lockerbie Main Sewer Servicing council: mitchell state: vic category: infrastructure classification: MAJOR status: active last_compiled: 2026-05-31 source_docs:
- web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt
- web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt
- web-research-L1-wallan-wastewater-futurewater.txt
- web-research-L1-wallan-wastewater-urban-water-solutions.txt
- web-research-L1-wallan-wastewater-yvw.txt
Wallan and Lockerbie Main Sewer Servicing
The Wallan and Lockerbie sewer servicing program is a major trunk wastewater intervention for Melbourne’s northern growth corridor because it changes sewerage from a local treatment-and-disposal constraint into a connected metropolitan network pathway. The core mechanism is simple: sewage from growth areas between Donnybrook, Beveridge, Lockerbie and Wallan can be collected by the Lockerbie Main Sewer, while the Wallan Sewage Treatment Plant can treat the portion needed for recycled water and divert excess sewage toward the metropolitan sewerage network once the wider infrastructure is complete (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
Background
Yarra Valley Water built the Lockerbie Main Sewer as a nine-kilometre sewer pipeline between Donnybrook and Beveridge to cater for growth in Melbourne’s northern growth area (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). The northern growth area is identified by Yarra Valley Water as an area where the Victorian Planning Authority projected about 300,000 people, 100,000 homes and about 80,000 jobs by 2050 (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
The Wallan Sewage Treatment Plant sits south-east of Wallan, between the rail line and the Hume Freeway, and services Wallan, Wallan East, Wandong and Heathcote Junction (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). The Wallan Sewage Treatment Plant also has capacity to service the development corridor extending from Craigieburn to Wallan, including the Wallara Waters and Mandalay developments (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). Urban Water Solutions states that the Wallan STP treats flow from Wallan, Beveridge and Wandong in Goulburn Valley Water’s operating area, which confirms that the servicing issue crosses utility operating-area boundaries rather than sitting wholly inside one local catchment (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt).
The institutional history matters because Wallan was originally serviced by Goulburn Valley Water, but government determined in 2004 that Yarra Valley Water would take over servicing responsibility, and Yarra Valley Water assumed responsibility for the Wallan Sewage Treatment Plant in 2006 (Source: web-research-L1-wallan-wastewater-futurewater.txt). That shift placed a growth-area servicing function onto Yarra Valley Water’s network planning, rather than leaving Wallan as a stand-alone local wastewater system (Source: web-research-L1-wallan-wastewater-futurewater.txt).
Analysis
Trunk Sewer Function and Growth-Area Sequencing
The Lockerbie Main Sewer is the collection and transfer spine for sewage flows from a majority of proposed new developments and communities in the Donnybrook, Beveridge and Lockerbie area (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). Its route runs next to the Melbourne to Sydney rail line and connects into the Amaroo Main Sewer at Donnybrook, which means the project links the Wallan-Lockerbie-Beveridge catchment into a downstream trunk sewer pathway rather than leaving each growth front dependent on isolated local treatment capacity (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
The pipeline includes 14 branch sewer connection points to service future development, so its planning role is not only to move existing sewage but to pre-position connection nodes for staged urban growth (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). In practical planning terms, those 14 branch points act like planned doors into the sewer system: subdivision staging can connect into a known trunk alignment, provided local reticulation and development approvals are aligned with the branch locations (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
The sewer also collects wastewater from the Wallan Sewage Treatment Plant, which means the Lockerbie Main Sewer and Wallan STP are functionally linked rather than separate projects (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). The STP can treat sewage required for recycled-water demand and, once all new infrastructure is constructed, divert excess sewage to Melbourne’s metropolitan sewerage network (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). This creates a two-pathway operating model: local treatment for recycled water where there is demand, and metropolitan transfer where local treatment or reuse demand is not the limiting factor (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
Treatment Capacity, Recycled Water and Disposal Constraint
The older Wallan plant had a nominal capacity above two million litres per day and used a lagoon-based treatment process (Source: web-research-L1-wallan-wastewater-futurewater.txt). Future Water reported that growth in the Wallan area, especially Wallara Waters and Mandalay, placed stress on that two-million-litres-per-day capacity (Source: web-research-L1-wallan-wastewater-futurewater.txt). The upgraded treatment approach included an activated sludge plant with four million litres per day dry-weather capacity, tertiary filtration and ultraviolet disinfection (Source: web-research-L1-wallan-wastewater-futurewater.txt).
The capacity doubling from about two million litres per day to four million litres per day is important because wastewater infrastructure must be sized for actual flows before lots can be serviced at scale (Source: web-research-L1-wallan-wastewater-futurewater.txt). If sewage inflows exceed local treatment or transfer capacity, subdivision yield may exist on planning maps but cannot be converted into occupied dwellings without interim disposal controls or trunk augmentation (Source: web-research-L1-wallan-wastewater-futurewater.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
The recycled-water component adds a second constraint: the Wallan STP produces more recycled water than current demand requires, so Yarra Valley Water considered disposal pathways for excess water (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). The proposed operating response is to partially upgrade irrigation and storage capacity and periodically discharge excess water under controlled conditions to Merri Creek via Taylors Creek (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). EPA Victoria granted Yarra Valley Water a discharge licence for this proposed discharge, and Yarra Valley Water states that the discharge is based on a comprehensive Environmental Risk Assessment (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
For land-use planning, this means the system is constrained by both sewage inflow and recycled-water outflow. New dwellings increase wastewater inflows, but recycled-water demand does not necessarily rise at the same rate or at the same time; until local demand, storage, irrigation and discharge permissions are balanced, the STP requires alternative wastewater disposal arrangements (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
Network Modelling and Operational Risk
Urban Water Solutions was engaged to include the Wallan STP into the Wallan sewerage network model, which indicates that the plant had to be represented as an active hydraulic component rather than as a simple end point (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt). The modelling used as-constructed plans and survey data from Yarra Valley Water, installed flow monitors at several locations, and used flow data to calibrate the hydraulic model (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt).
The modelling conclusion is material: Urban Water Solutions found that operation of the STP is integral to understanding sewerage network system performance (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt). In plain terms, the network behaves differently depending on how the treatment plant is operated, because flows may be treated locally, supplied as recycled water, stored, discharged under licence, or transferred through the trunk sewer system (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
Urban Water Solutions also states that the Wallan STP is transforming to operate as a sewer mine to meet recycled-water demands of up to 40 litres per second in the local area (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt). That 40 litres per second figure is a useful operating signal because it describes the scale of local recycled-water extraction that the model needed to understand, although the source does not provide the full design demand curve, seasonal profile or ultimate population-equivalent capacity (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt).
Delivery Timeline and Construction Method
Design for the Lockerbie Main Sewer was completed in late 2019, construction started in March 2020, and construction was completed in October 2021 (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). Yarra Valley Water states that the Lockerbie Main Sewer was operating in October 2021 and that local customers between Donnybrook and Wallan were able to connect to the sewer network at that time (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
The construction sequence shows that the project used both open-cut trenching and tunnelling (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). In June 2020, works included open-cut construction north of Minton Street and between Donovans Lane and Beveridge Road, tunnelling near Donovans Lane in Beveridge, access tracks and fencing between Donnybrook Road and Merri Creek, and continuing work north of Merri Creek (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). In September 2020, works included open trenches between Merri Creek and Beveridge Road, tunnelling opposite Donovans Lane and north of Merri Creek, access tracks between Donnybrook Road and Merri Creek, and northward open-trench construction from near Donnybrook Road (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
This construction mix matters because trunk sewers in growth corridors are not just pipe-capacity projects; they also create corridor impacts on waterways, rail-adjacent land, roads, farms, culturally sensitive land and future urban parcels (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). The use of tunnelling near sensitive or constrained locations reduced surface disturbance in parts of the alignment, while open-cut construction created a broader restoration task across affected land (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
Cultural Heritage and Alignment Risk
Yarra Valley Water worked with Jacobs and the Wurundjeri Woi Wurrung Cultural Heritage Corporation to identify potential cultural heritage impacts from excavation (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). The response included redesigning the sewer, extending tunnelled sections to avoid sensitive sites, using trenchless construction techniques, minimising construction footprints, and preventing topsoil disturbance through geofabric and crushed rock (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
The cultural salvage program ran for 12 months and used hand and mechanical archaeological digs to identify, record and preserve artefacts (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). Yarra Valley Water states that the program uncovered more than 6,000 artefacts from the project area, many from stony rises used by Wurundjeri ancestors for camping or tool making (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). Yarra Valley Water also states that the total salvage area was 10,200 square metres and that this was the first large-scale salvage of stony rises in Victoria (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
The planning implication is that trunk sewer alignment risk in this corridor includes Aboriginal cultural heritage, not only engineering cost and hydraulic grade. Any future branch sewers, local reticulation or augmentation works near stony rises, Merri Creek, Taylors Creek or similar landscape features may need early cultural heritage investigation before final alignment, construction technique and staging can be settled (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
Capital Scale and Servicing Strategy
Yarra Valley Water describes the Wallan STP upgrade as part of a 200 million investment in new sewerage infrastructure that will ultimately connect Wallan and surrounds to Melbourne's metropolitan sewerage network (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). Future Water separately reports a 20 million investment to replace the Wallan Sewage Treatment Plant, which provides source water for the Wallan Recycled Water Treatment Plant (Source: web-research-L1-wallan-wastewater-futurewater.txt). These figures likely refer to different layers of the same servicing program: the 20 million plant replacement and recycled-water source infrastructure sits inside a broader 200 million sewerage infrastructure program (Source: web-research-L1-wallan-wastewater-futurewater.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
The sources do not provide a development contributions plan, cost apportionment schedule, branch sewer charge, reimbursement agreement or lot-equivalent levy (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). Because of that gap, this page can identify the servicing mechanism and its growth-area effect, but it cannot quantify how costs are allocated between Yarra Valley Water, developers, landowners, customers or broader tariffs.
Current Status
The Lockerbie Main Sewer was completed in October 2021 and is operating (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt). Local customers between Donnybrook and Wallan were able to connect to Yarra Valley Water’s sewer network after the sewer became operational in October 2021 (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
The Wallan STP has been upgraded to service new developments north of Melbourne and further growth (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). The STP currently has a role in recycled-water supply for toilet flushing, garden watering, car washing and laundry use as new developments are completed (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). The STP also requires controlled arrangements for excess recycled water because current demand is lower than production (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
Dependencies
- Blocks: Without the Lockerbie Main Sewer and Wallan STP operating model, urban growth between Donnybrook, Beveridge, Lockerbie and Wallan would face a hard wastewater servicing constraint because local sewage must be collected, treated, reused, discharged under licence or transferred to the metropolitan sewerage network (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
- Blocked by: Further development connections depend on local reticulation to the 14 branch connection points, adequate downstream capacity through the Amaroo Main Sewer connection, STP operating settings, recycled-water demand, and discharge licence conditions for excess water (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
- Informed by: The project was informed by detailed design completed in late 2019, hydraulic modelling using as-constructed plans, survey data and flow-monitor calibration, and cultural heritage work with Jacobs and the Wurundjeri Woi Wurrung Cultural Heritage Corporation (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt) (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt).
- Implements: The infrastructure implements Yarra Valley Water’s sewerage strategy for the new development corridor extending from Craigieburn through to Wallan (Source: web-research-L1-wallan-wastewater-futurewater.txt).
- Conflicts with: The sources do not identify a formal planning conflict, but they do show operational tension between recycled-water production and current recycled-water demand, requiring storage, irrigation upgrades and controlled discharge to Merri Creek via Taylors Creek (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt).
Cross-Jurisdictional Links
This infrastructure has cross-boundary significance because it services a growth corridor extending from Craigieburn to Wallan and supports communities and development fronts in Donnybrook, Beveridge, Lockerbie, Wallan, Wallara Waters and Mandalay (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). The connection to the Amaroo Main Sewer at Donnybrook links the Wallan-Lockerbie-Beveridge catchment into a metropolitan sewerage network pathway rather than a purely local Mitchell Shire wastewater system (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
The servicing history also crosses water-authority boundaries because Wallan was originally serviced by Goulburn Valley Water, government reassigned servicing responsibility to Yarra Valley Water in 2004, and Yarra Valley Water assumed responsibility for the Wallan STP in 2006 (Source: web-research-L1-wallan-wastewater-futurewater.txt). Urban Water Solutions states that Wallan STP treats flow from Wallan, Beveridge and Wandong in Goulburn Valley Water’s operating area, which reinforces the need to treat wastewater servicing as a regional network issue rather than a single-council asset issue (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt).
Gaps in This Analysis
The available source documents are mostly public web pages and consultant profile pages, not full engineering reports, statutory planning documents or water authority capital plans (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt) (Source: web-research-L1-wallan-wastewater-futurewater.txt) (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt) (Source: web-research-L1-wallan-wastewater-yvw.txt). This limits the analysis in five ways.
First, the corpus does not include the Yarra Valley Water sewerage strategy for the Craigieburn-to-Wallan corridor, even though Future Water says that such a strategy was prepared (Source: web-research-L1-wallan-wastewater-futurewater.txt). Second, the corpus does not include the full Environmental Risk Assessment behind the EPA discharge licence, so this page cannot assess Merri Creek or Taylors Creek water-quality thresholds, discharge volumes, seasonal limits or monitoring conditions (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). Third, the corpus does not include detailed hydraulic modelling outputs, so this page cannot quantify ultimate equivalent-population capacity, peak wet-weather flow, emergency storage, pump station limits or downstream Amaroo Main Sewer constraints (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt). Fourth, the corpus does not include a cost recovery or contributions document, so this page cannot state who pays for the 20 million plant replacement or the wider 200 million sewerage program (Source: web-research-L1-wallan-wastewater-futurewater.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt). Fifth, the corpus does not include the cultural heritage management plan or salvage report, so this page can identify the 10,200 square metre salvage program and more than 6,000 artefacts, but cannot map exact heritage-sensitive locations or future alignment exclusion areas (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt).
These gaps should be treated as important corpus gaps for _gaps because sewer capacity, discharge permission, cultural heritage constraints and cost apportionment all affect the practical sequencing of Wallan, Beveridge, Lockerbie, Donnybrook, Wallara Waters and Mandalay growth-area development (Source: web-research-L1-wallan-lockerbie-main-sewer-yarra-valley-water.txt) (Source: web-research-L1-wallan-sewage-treatment-yarra-valley-water.txt) (Source: web-research-L1-wallan-wastewater-futurewater.txt) (Source: web-research-L1-wallan-wastewater-urban-water-solutions.txt).