About LEVEE

What LEVEE is

LEVEE is a free map of what is known about flooding in NSW. It brings council flood studies together in one place and explains them in plain terms, so you can see what applies to a property without reading a technical report.

The name stands for Level, Extent, Velocity, Exposure, Events. Those are the five things that matter about a flood, and they are the five headings on the map.

Why it exists

Flood information in NSW is scattered. It sits across hundreds of council studies, in formats that are hard to find and harder to read. Someone who wants to know whether a property floods, and how badly, often cannot get a straight answer. LEVEE gathers what councils have published openly into one consistent map.

Behind the scattered information sits a set of problems the industry recognises from both sides of the counter. Technical language is a barrier for planners and the public alike. Flooding is typically an afterthought in a project rather than a constraint considered from the start. The quality of an assessment is limited by the expertise of whoever is doing the assessing, and uncertainty produces risk averse, impractical standards. Applications turn into a blame game that pits applicants against councils. Misunderstanding and misinformation are widespread, and flood planning is too rarely treated as the real and present risk it is.

Each of those is made worse by information being hard to reach, and each is eased by putting it in one place in plain terms. That is the job.

Who it serves

Flood information is community infrastructure. It is publicly funded, it concerns people's homes and their safety, and it should not require an expert intermediary to understand. Work that protects people should be findable by the people it protects.

For the public, LEVEE translates technical mapping into plain language and opens access to information that already exists. For planners, it offers consistent, simpler terminology for flood controls and removes the repeated cost of locating and interpreting flood information council by council. For engineers, it is a shared reference to build on: a consistent baseline that lifts submission standards and streamlines access to study inputs and outputs. For developers, it means site screening before purchase, faster due diligence across council areas, and notice when a new study is adopted over land already owned. And for industry bodies, it provides an evidence base for policy change to improve the accessibility and consistency of published flood data across NSW.

A platform built by industry for industry also gives the profession a say in how flood information is presented that it would never have if government built it.

The roadmap

The prototype is already live: everything planned builds on a working platform rather than a proposal. The first stage is engagement, with the ingestion pipeline complete and Illawarra layers live from adopted studies, in direct consultation with council staff.

From there, coverage extends across the Greater Sydney council areas that publish grid data, anchored by the openly licensed 2024 Hawkesbury-Nepean River Flood Study, the cleanest licence position available: one open dataset covering the floodplain across eight council areas. The aim is a fully operational site for Greater Sydney within twelve months, with licensing agreements signed where required. Where a council does not provide freely available flood study data, consultation seeks to understand why. That is research, not a workaround, and not pressure.

Beyond that sit automated study monitoring, alerting users when a new study is adopted or a draft goes on exhibition in their area, and a statewide audit published to industry bodies: the state of flood data accessibility in NSW. The roadmap is deliberately long. LEVEE is intended as infrastructure that outlasts any one project, and Perennial has committed to maintaining it whether or not it is ever funded externally.

Who is behind it

LEVEE is built and run by Perennial Consulting Engineers Pty Ltd, chartered civil engineers specialising in flood risk assessment and stormwater management. The platform is a free-of-charge courtesy alongside the firm's professional work.

Perennial's experience covers both sides of the fence, in local government and in private consulting. Most flooding disputes are not disagreements about hydrology. They are misunderstandings: a council officer has duties under the planning controls, an applicant has a proposal they believe is sound, and the exchange turns to fault rather than to the specific matters that would settle it. Reconciling that is a large part of the firm's practice, at every scale from a single alteration to a hospital.

The next step for the business is a shift from practising civil design toward education, advocacy and advisory work, and LEVEE embodies that. Underneath it sits advocacy for wider uptake of open licensing across published flood studies, with individual licensing agreements signed where needed in the interim.

On fairness: contributed studies are always attributed to the firm that produced them, and Perennial's own work is not hosted on the platform. The owner of a directory should not be competing inside it.

If you need advice on a particular property or development, the team can help directly. Contact Perennial.

A common cause

Civil and flood engineering shapes whether a home is safe, a street drains, or a neighbourhood endures. For most people it remains a black box of jargon, models and approval hurdles. Perennial's purpose is simple: create simple solutions that last. The kind of design that is easy to approve, easy to build, easy to maintain, and still functions decades from now.

Engineering will never be fully accessible, and that is exactly why we keep at it.