title: Stormwater Asset Management Plan council: moorabool state: vic category: infrastructure classification: MINOR status: active last_compiled: 2026-05-31 source_docs:

asset-management-plan_stormwater.pdf

Stormwater Asset Management Plan

Moorabool’s Stormwater Asset Management Plan is less a construction program than a risk-control framework for keeping a large buried drainage network serviceable while growth adds a second wave of assets to Council’s balance sheet. The plan records a current stormwater portfolio of 19,529 assets with a replacement value of $104.576 million, then identifies a growth-driven increase to$ 144.6 million by 2032 as new development hands over further pipes and pits to Council (Source: asset-management-plan_stormwater.pdf, pp.1, 20).

The central planning issue is that the plan relies on limited asset evidence. Council has not yet completed a comprehensive underground drainage condition assessment, its asset register was estimated to be only 75% current, and the plan’s funding settings are explicitly interim until CCTV sampling, capacity analysis and predictive modelling improve the evidence base (Source: asset-management-plan_stormwater.pdf, pp.7-9, 24, 27-28).

Background

The plan covers the 2022-2032 period and is intended to guide long-term management of Council-controlled stormwater drainage assets, including investment decisions, service levels and asset management activities over a 10-year planning horizon (Source: asset-management-plan_stormwater.pdf, p.1). It sits under Council’s broader Asset Management Strategy and responds to the Local Government Act 2020 requirement for an Asset Plan covering at least the next 10 financial years and addressing maintenance, renewal, acquisition, expansion, upgrade, disposal and decommissioning of infrastructure assets under Council control (Source: asset-management-plan_stormwater.pdf, pp.1, 15).

The network described by the plan is the everyday drainage system that collects runoff from roofs, paved areas, roads, footpaths and reserves and moves it through pits, pipes, culverts, open channels, natural waterways and road reserves to creeks, rivers and catchments (Source: asset-management-plan_stormwater.pdf, p.5). The plan treats this system as public health, property-protection and amenity infrastructure because its function is to collect, transport and dispose of stormwater runoff safely and efficiently (Source: asset-management-plan_stormwater.pdf, p.5).

The plan’s asset boundary is important. It includes stormwater drainage assets for which Council is the responsible authority, but excludes assets owned or maintained by other authorities, including Melbourne Water and DELWP, and excludes creeks, rivers, unlined channels and private household drainage up to the discharge point (Source: asset-management-plan_stormwater.pdf, p.5). That boundary means the plan is strongest on Council’s asset register and weaker on whole-of-catchment flood behaviour, receiving-water impacts and upstream or downstream assets managed outside Council’s direct control (Source: asset-management-plan_stormwater.pdf, pp.5, 21-22).

Analysis

Asset Base, Condition and Data Confidence

Council’s stormwater portfolio comprises 19,529 recorded assets across 301 road box culverts, 2,133 road pipe culverts, 12 gross pollutant traps, 8,650 pipes and 8,427 pits, with recorded linear drainage assets totalling 261.34 km (Source: asset-management-plan_stormwater.pdf, p.5). By replacement value, stormwater drains dominate the portfolio at $74.454 million, followed by pits at$ 20.060 million, road culverts at $9.835 million and GPTs at$ 226,440 (Source: asset-management-plan_stormwater.pdf, p.7). The practical effect is that buried pipes are the main financial exposure: they represent about 71.2% of replacement value and are also the asset type where visual condition is hardest to verify without CCTV inspection (Source: asset-management-plan_stormwater.pdf, pp.7-8).

The reported balance-sheet position appears healthy at first reading. The stormwater portfolio had a replacement cost of $104.576 million, accumulated depreciation of$ 24.100 million, fair value of $80.476 million and annual depreciation of$ 1.026 million as at 30 June 2021 (Source: asset-management-plan_stormwater.pdf, pp.1, 7). The remaining service index was reported at 77% against a target greater than 70%, and the average network condition was reported as 1.3 on a 0-to-6 scale where 0 is new and 6 is end of life (Source: asset-management-plan_stormwater.pdf, pp.7, 26). Council also reported that about 79% of drainage assets were in good condition or better and about 19% were in fair condition (Source: asset-management-plan_stormwater.pdf, p.7).

Those figures need to be read cautiously because the condition base is not yet inspection-led. The plan states that Council had not undertaken comprehensive condition assessments of the underground drainage system, and that condition had been assigned using known construction dates, estimated area age and limited CCTV in known defect locations (Source: asset-management-plan_stormwater.pdf, p.8). The plan also states that Council’s asset register was estimated to be 75% up to date at the time of preparation (Source: asset-management-plan_stormwater.pdf, p.7). In plain terms, the plan knows the broad shape and value of the drainage network, but it does not yet have the inspection coverage needed to prove which underground pipes are structurally sound, under-capacity or approaching failure (Source: asset-management-plan_stormwater.pdf, pp.7-9).

The plan’s own improvement program recognises that data weakness. It requires annual CCTV sampling of underground pipes, condition updates in the asset register, capture of open drains and basins, a known flooding-location register, drainage capacity analysis and predictive lifecycle modelling by 2023-2024 milestones (Source: asset-management-plan_stormwater.pdf, pp.27-28). Until those actions are complete, the plan’s renewal forecasts are better understood as a holding position than as a fully tested asset-risk model (Source: asset-management-plan_stormwater.pdf, pp.24, 27-28).

Funding Settings and the Maintenance Gap

The plan adopts a 10-year capital renewal allocation of $1.207 million and a 10-year maintenance allocation of$ 3.64 million, or about $364,000 per year, for the existing stormwater portfolio (Source: asset-management-plan_stormwater.pdf, pp.4, 24-25). The annual renewal profile rises from$ 83,500 in 2022/23 to $138,600 in 2031/32, while maintenance rises from$ 295,500 to $447,800 over the same period (Source: asset-management-plan_stormwater.pdf, p.25). Council states that this level is considered sufficient in the short term because stormwater assets have long useful lives, but it also states that better predictive modelling depends on statistical CCTV analysis of the underground drainage system (Source: asset-management-plan_stormwater.pdf, pp.4, 24).

The maintenance ratio is the warning signal in the plan. Council’s maintenance sustainability ratio was less than 0.5% of replacement value, against a target range of 2-5% (Source: asset-management-plan_stormwater.pdf, p.26). The plan also lists as a key assumption that maintenance funding will progressively increase to at least 2% of asset replacement value (Source: asset-management-plan_stormwater.pdf, p.27). If applied to the current $104.576 million asset base, a 2% maintenance benchmark would imply about$ 2.09 million per year, which is materially above the 2022/23 maintenance allocation of $295,500 and the 2031/32 allocation of$ 447,800 (Source: asset-management-plan_stormwater.pdf, pp.1, 25-27).

This does not automatically prove a present service failure, because the plan reports low measured poor-condition exposure and limited backlog in the current asset base (Source: asset-management-plan_stormwater.pdf, pp.2, 18, 26). It does show that the financial model is sensitive to the missing condition and capacity work. If CCTV and capacity studies identify a larger defect or under-capacity pool than currently assumed, the existing 10-year renewal program may not be enough to avoid future catch-up expenditure (Source: asset-management-plan_stormwater.pdf, pp.8, 24, 27-28).

Growth, Asset Handover and Long-Term Liability

Growth is the largest mechanism changing the stormwater portfolio. The plan uses population forecasts showing Moorabool rising from 36,344 people in 2021 to 63,831 people in 2041, a 75.6% increase (Source: asset-management-plan_stormwater.pdf, p.19). It also identifies major growth areas at Ballan, Hopetoun Park North, Merrimu, and Parwan Employment and Parwan Station, with approximately 3,000 lots at Ballan, 850 lots at Hopetoun Park North, 7,200 lots at Merrimu, and approximately 4,000 lots plus more than 5,000 jobs at Parwan Employment and Parwan Station (Source: asset-management-plan_stormwater.pdf, p.20).

The immediate delivery model is developer construction followed by Council handover. The plan estimates that growth in Ballan, Merrimu and Hopetoun Park North will result in Council being gifted about 239 km of pipes and 8,400 pits worth about $40.04 million (Source: asset-management-plan_stormwater.pdf, pp.4, 20). That handover almost doubles the length of recorded pipe-like assets when compared with the existing 261.34 km of culverts and pipes in the plan’s asset table, and it materially expands the future maintenance task even though the initial construction cost is not borne directly through Council renewal capital (Source: asset-management-plan_stormwater.pdf, pp.5, 20).

The plan quantifies the balance-sheet effect of this growth. By 2032, replacement value is forecast to rise from $104.6 million to$ 144.6 million, annual depreciation from $1.03 million to$ 1.4 million, and maintenance from $295,500 to$ 2.89 million (Source: asset-management-plan_stormwater.pdf, p.20). The important mechanism is that gifted assets reduce the upfront delivery burden for Council but increase Council’s ongoing inspection, maintenance, renewal and asset-data obligations over the lifecycle of those assets (Source: asset-management-plan_stormwater.pdf, pp.10, 20).

Planning controls are therefore part of the asset-management system. The plan proposes controlling discharge from new development through on-site retention systems, using planning and engineering subdivision processes, and using Development Control Plans so new development contributes to downstream drainage upgrades where development impacts the existing network (Source: asset-management-plan_stormwater.pdf, p.21). It also identifies drainage capacity analysis as the process for finding where the existing network must be upgraded to meet current design standards (Source: asset-management-plan_stormwater.pdf, p.21). This links the SAMP directly to ballan, merrimu, hopetoun-park-north and parwan-employment-and-parwan-station, because subdivision staging and discharge controls can change whether downstream Council assets need upgrade works (Source: asset-management-plan_stormwater.pdf, pp.20-21).

Service Levels, Statutory Effect and Operational Controls

The plan defines service levels as current service levels delivered within Council’s financial and human resources while meeting statutory requirements (Source: asset-management-plan_stormwater.pdf, p.17). Customer measures include a target for more than 60 community survey satisfaction, fewer than 100 annual new or renewal requests, fewer than 300 annual maintenance requests, GPT installation at strategic locations, and more than 80% of requests responded to within target (Source: asset-management-plan_stormwater.pdf, p.17). The 2021 data was incomplete: Council had 67 new or renewal requests and 203 maintenance requests, but stormwater-specific satisfaction, GPT performance and response-time data were still to be collected (Source: asset-management-plan_stormwater.pdf, p.17).

Technical measures are simpler and currently more favourable. The plan sets a three-year condition assessment cycle, a target average portfolio condition below 3, and a target that less than 5% of the network be above condition score 4; the reported 2021 performance was an average condition of 1.3 and less than 1% above condition score 4 (Source: asset-management-plan_stormwater.pdf, p.18). The unresolved issue is that these technical measures depend on the same condition dataset that the plan says is not yet comprehensive for underground drainage (Source: asset-management-plan_stormwater.pdf, pp.8, 18).

The statutory and standards framework is broad. The plan identifies the Local Government Act 2020, Road Management Act 2004, Public Health and Wellbeing Act 2008, Catchment and Land Protection Act 1994, Planning and Environment Act 1987, Environment Protection Act 1970, Water Act 1989, Water Management Act 2000 and Environment Protection water-quality policy as relevant to stormwater asset management (Source: asset-management-plan_stormwater.pdf, pp.15-16). It also identifies the Moorabool Planning Scheme, Australian Rainfall and Runoff, ISO 55000, accounting standards, AMAF and the International Infrastructure Management Manual as relevant standards or guidance (Source: asset-management-plan_stormwater.pdf, pp.15-16). The statutory effect is practical rather than site-specific: the plan does not itself rezone land, but it informs how Council assesses drainage obligations, manages road-reserve drainage, accounts for stormwater assets and protects receiving-water quality (Source: asset-management-plan_stormwater.pdf, pp.15-17, 21).

Risk, Criticality and Missing Capacity Evidence

The plan categorises stormwater assets into major and minor criticality classes. Major assets include stormwater assets in trunk collector and collector road reserves and pipes 750 mm diameter or greater with associated pits, while minor assets include access-street or place-road assets and pipes below 750 mm with associated pits (Source: asset-management-plan_stormwater.pdf, p.22). This hierarchy matters because larger trunk and collector assets are more likely to produce broader service consequences if they fail or are under-capacity (Source: asset-management-plan_stormwater.pdf, p.22).

The risk-management framework is still incomplete. Council had a Risk Framework and Risk Management Policy aligned with ISO 31000-2018, but the plan states that the detailed asset risk and treatment plan would be documented in a future Stormwater Management Plan (Source: asset-management-plan_stormwater.pdf, pp.22-23). The plan also says intervention levels for day-to-day maintenance faults and localised failures will be documented in a future Stormwater Management Plan (Source: asset-management-plan_stormwater.pdf, pp.9-10). That leaves an important operational gap: the SAMP explains the architecture for risk management, but the source document does not provide a location-specific risk register, flood-priority list or treatment schedule (Source: asset-management-plan_stormwater.pdf, pp.9-10, 22-23).

Current Status

The plan is current for the 2022-2032 horizon and states that it will be reviewed and updated in the year following Council general elections, consistent with Local Government Act 2020 section 92.4 (Source: asset-management-plan_stormwater.pdf, p.29). It also states that the funding plan will be reviewed with the next SAMP update in 2026 as new information becomes available on growth demand and asset lifecycle (Source: asset-management-plan_stormwater.pdf, p.24). On the source record available here, the most important live tasks are the improvement actions scheduled for 2022-2024: finalising the Stormwater Business Process Manual, implementing CCTV sampling, capturing open drains and basins, preparing a flooding-location register, undertaking drainage capacity analysis, and completing predictive lifecycle modelling (Source: asset-management-plan_stormwater.pdf, pp.27-29).

Dependencies

Blocks: The plan does not directly block land use approvals, but the drainage capacity work it calls for can affect subdivision engineering requirements, downstream upgrade obligations and discharge limits for new development (Source: asset-management-plan_stormwater.pdf, p.21).
Blocked by: Stronger renewal forecasting is blocked by incomplete CCTV condition evidence, incomplete capacity analysis, incomplete flooding-location data and an asset register that was estimated to be 75% up to date (Source: asset-management-plan_stormwater.pdf, pp.7-9, 27-28).
Informed by: The plan is informed by Council’s Asset Management Strategy, Asset Management Policy 2021, Risk Management Policy 2019, Asset Register in Assetic Cloud, Local Government Community Satisfaction Survey 2021 and population forecasts prepared by .id in November 2020 (Source: asset-management-plan_stormwater.pdf, pp.1, 7, 11, 16-17, 19).
Implements: The plan implements Council asset-planning obligations under the Local Government Act 2020 and aligns stormwater management with Council goals for governance, environmental impact, social outcomes and fit-for-purpose infrastructure (Source: asset-management-plan_stormwater.pdf, pp.12, 15).
Conflicts with: No direct policy conflict is identified in the source document, but the plan’s current maintenance allocation is materially below the stated 2-5% maintenance sustainability target and below the plan’s assumption that maintenance funding will progressively rise to at least 2% of replacement value (Source: asset-management-plan_stormwater.pdf, pp.26-27).

Cross-Jurisdictional Links

The plan identifies external stormwater responsibilities rather than detailed cross-boundary projects. It excludes assets owned or maintained by Melbourne Water and DELWP, notes that the Water Act 1989 creates waterway management authorities such as Melbourne Water, and identifies state and federal government departments as stakeholders that may provide advice, instruction and support funding for drainage-network management (Source: asset-management-plan_stormwater.pdf, pp.5, 13, 15). No adjacent-council drainage program, catchment-scale flood study, Melbourne Water capital program or state agency works program is included in the source document, so cross-jurisdictional consequences cannot be mapped beyond these institutional links (Source: asset-management-plan_stormwater.pdf, pp.5, 13, 15).

Gaps in This Analysis

This page is based on one source document, so the analysis is intentionally limited to the Stormwater Asset Management Plan and should be cross-checked against _gaps when a broader council corpus is compiled (Source: asset-management-plan_stormwater.pdf). The most important missing documents are the Asset Management Strategy, Asset Management Policy 2021, draft Stormwater Business Process Manual, future Stormwater Management Plan, Community Infrastructure Plan, drainage capacity studies, known flooding-location register, CCTV condition sampling results, Development Control Plans for growth areas, and any growth-area drainage strategies for Ballan, Merrimu, Hopetoun Park North and Parwan (Source: asset-management-plan_stormwater.pdf, pp.1, 8-10, 20-22, 27-28). Without those documents, this page can identify the mechanism and scale of the stormwater issue, but it cannot map specific flood-prone locations, pipe-capacity constraints, basin requirements, subdivision-stage triggers or downstream upgrade costs (Source: asset-management-plan_stormwater.pdf, pp.8-9, 20-22, 27-28).

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