How to Prepare for Stormwater Inspections

A stormwater inspection is far more productive when the inspector can safely access every relevant asset, compare the system against approved information and see its actual condition without avoidable obstructions. Knowing how to prepare for stormwater inspections helps homeowners, strata managers and facilities teams reduce delays, identify issues earlier and receive a clearer path to compliance.

Preparation does not mean trying to diagnose or repair every issue yourself. It means making the site accessible, gathering the right records and noting anything that has changed since the last inspection. That gives the inspection team a reliable starting point and helps ensure defects are assessed in the context of the whole drainage system.

Confirm why the inspection is being completed

Start by establishing the purpose of the inspection. A routine maintenance review is different from an inspection required for a property handover, council condition, compliance report, recurring flooding concern or proposed development work.

The reason matters because it determines what needs to be assessed and documented. An OSD system, for example, may require verification of its storage, outlet controls, signage and maintenance condition. A WSUD asset may need closer attention to sediment build-up, vegetation, filters, overflow arrangements and whether it is functioning as designed.

If the inspection follows a concern, provide a short, factual description. Include where the issue occurs, how often it happens, whether it follows heavy rainfall and what has already been observed. Photos with dates can be useful, particularly where ponding, overflowing pits, damaged grates or surface deterioration only appear under certain conditions.

Gather plans, approvals and prior reports

The most useful documents are the approved stormwater drainage plan, any OSD or WSUD design drawings, construction records, previous inspection reports and maintenance logs. For strata properties, this information may sit with the strata manager, building manager, developer or original project records.

Do not delay an inspection if every document cannot be found. A site assessment can still identify visible defects and maintenance needs. However, approved plans and past reports allow the inspector to check whether assets are located and configured as intended, and whether previously identified works have been completed.

It is also worthwhile to locate relevant council correspondence, occupation conditions, certificates and maintenance requirements. Some systems have specific obligations that continue for the life of the property. A missing report or undocumented alteration can create uncertainty later, especially when a property is sold, renovated or reviewed by council.

Make all stormwater assets accessible

Access is one of the most common reasons an inspection becomes incomplete. Before the appointment, walk through the property and identify where pits, grates, drains, gutters, downpipes, detention structures, tanks, pumps and visible pipework are located.

Move vehicles, pot plants, outdoor furniture, stored materials and rubbish away from pit lids, grates and access points. Trim back dense vegetation where it prevents a safe visual inspection. If an asset is beneath a locked gate, basement, plant room or shared area, arrange keys, codes and authorised access in advance.

This is particularly relevant on strata and commercial sites, where an inspection may involve common property, a roof area, loading zone, basement or restricted maintenance space. Confirm who will provide access and whether any site induction, sign-in process or safety requirement applies. A simple access plan avoids lost time on the day.

Do not attempt to lift heavy lids, enter pits or confined spaces, or dismantle system components yourself. These tasks require appropriate controls, equipment and trained personnel. The aim is to clear the approach to the asset, not create a safety risk.

Carry out a practical pre-inspection check

You do not need specialist equipment to spot obvious changes around the site. A visual check before the inspection can help you give the contractor useful direction and prevent small concerns from being overlooked.

Look for these common indicators:

Leaves, sediment, mulch or litter blocking grates and drains.
Cracked, sunken or loose pit lids, grates and surrounding surfaces.
Ponding after rainfall, especially near entrances, garages, footpaths or landscaped areas.
Staining, erosion or displaced soil around drains, outlets and retaining edges.
Overflow marks, unusual odours, noisy pumps or visible damage to tanks and pipework.

Record what you find, but avoid making assumptions about the cause. A blocked grate may be only the visible symptom. The underlying issue could involve downstream pipework, a damaged connection, insufficient maintenance, altered landscaping or a detention component that is not operating correctly.

Check recent changes to the property

Stormwater systems are often affected by changes that appear unrelated to drainage. New paving, decking, garden beds, retaining walls, sheds, pool areas, driveway works and roof alterations can change how runoff moves across a site. They can also cover inspection points or interfere with designed overland flow paths.

Tell the inspector about any works completed since the last assessment, including work undertaken by previous owners or contractors. If plans are available, provide them. Even minor changes can matter where a system relies on precise levels, clear overflow routes or accessible maintenance points.

For residential properties, pay particular attention to landscaping. Soil, mulch and garden edging can gradually build up around grates and reduce their effective capture level. Inlets that once sat clear of the finished surface can become partially buried, allowing runoff to bypass them during rainfall.

Prepare for OSD and WSUD inspection requirements

OSD and WSUD systems need more than a quick look at surface grates. They are purpose-built assets designed to manage stormwater quantity, quality or both, and their performance depends on regular inspection and maintenance.

For an OSD system, ensure access is available to relevant pits, chambers, outlet structures, screens, control devices and signage. Have any approved OSD plans and previous compliance records ready. If a component has been modified, damaged or covered, disclose this before the inspection so the assessment can focus on the real condition of the asset.

For WSUD assets such as raingardens, biofiltration areas, swales or treatment devices, avoid clearing vegetation or replacing filter media immediately before an assessment unless instructed. The inspector needs to see the asset as it is maintained. Instead, advise when it was last serviced and note any recent sediment removal, planting work or drainage changes.

The right maintenance approach depends on the system design. Over-cleaning can be as unhelpful as neglect if it disturbs components intended to support treatment performance. A specialist assessment can distinguish between routine housekeeping, planned maintenance and remedial works.

Brief occupants, tenants and site staff

If other people use the property, let them know an inspection is scheduled. Ask them not to park over pits or drains, and ensure pets are secured where required. For strata and managed sites, advise occupants if access is needed through courtyards, garages or common areas.

A nominated contact should be available to answer practical questions, provide access and explain known issues. This does not need to be a technical person. Clear information about locations, timing and prior concerns is often enough to help the inspection proceed efficiently.

Know what a useful inspection outcome looks like

A proper stormwater inspection should leave you with more than a verbal opinion. Depending on the scope, the outcome may include photographs, asset observations, identified defects, maintenance recommendations, compliance findings and a prioritised remedial plan.

Not every defect requires immediate major work. Some issues can be addressed through scheduled cleaning or minor repairs, while others may require investigation, design advice or more substantial remediation. The priority should reflect safety, compliance exposure, risk of property damage and the likelihood of further deterioration.

Ask for recommendations in plain language, with the reason for each action clearly stated. For property managers and strata committees, this makes it easier to obtain approval, budget for works and demonstrate that maintenance decisions have been made responsibly.