Flood planning is an important aspect of strategic land use planning in NSW and aims to minimise risk to life, property and the environment. Development on land that is subject to flood planning controls must be compatible with the land’s flood hazard.
A consent authority considering a development application (DA) on flood prone land must be satisfied that the development “… is compatible with the flood hazard of the land”.
The Court of Appeal recently held that the relevant date at which it should be compatible is the date of determination, not some future time when flood mitigation works might be carried out.
Future flood mitigation works, which are not part of the development application, are not relevant in assessing compatibility.
When is a development compatible with the flood hazard?
In Michael Brown Planning Strategies Pty Ltd v Wingecarribee Shire Council  NSWCA 137 the Court of Appeal considered whether future flood mitigation works, which were not part of the development application for a residential flat building, were relevant in assessing whether the development was compatible with the flood hazard of the land.
Clause 7.9(3)(a) of the Wingacarribee Local Environmental Plan provides:
“… development consent must not be granted to development on land to which this clause applies unless the consent authority is satisfied that the development is compatible with the flood hazard of the land”.
This type of clause is common in Local Environmental Plans (LEPs) in areas subject to flooding and flood planning.
The evidence was that the development was compatible with the flood hazard of the land if an existing culvert, near a railway line, was enlarged to provide better drainage under the railway line. The hydrologists for both parties agreed that the culvert enlargement work needed to occur first, before the development could proceed.
The culvert work was not part of the development application, but was to be carried out by the railway authority. The work had not yet been carried out and there was no evidence about when it would be carried out or even that it had been approved.
The applicant argued that clause 7.9(3)(a) enables a consent authority to consider future events when assessing compatibility, in this case, the future culvert upgrade work. The applicant argued the development would not take place until the culvert enlargement work had occurred. By that time, the development would be compatible with the flood hazard of the land. The applicant argued this was consistent with the objectives of the flood control clause which required consideration of the actual development when carried out, with the flood hazard of the land at that point in time.
The Court of Appeal, in upholding the decision of the Land and Environment Court, found that:
- The date for assessing compatibility in clause 7.9(3) is at the date of determination of the development application. Sections 4.15(a) and (c) of the Environmental Planning and Assessment Act require consideration of documents in existence when the application is assessed and suitability of the site as at the date consent is granted.
- Clause 7.9(3) contains a precondition to the engagement of the consent authority’s jurisdiction to approve a development. Therefore, that clause cannot also require an evaluative judgment about when future flood mitigation works might be complete so as to enable the development to satisfy clause 7.9(3).
- Clause 7.9(3) requires an assessment of the compatibility of the “development”. The culvert upgrade work was not part of the development and so could not be considered when assessing the compatibility of the development with the flood hazard of the land.
Key points for applicants and councils
- Development must be compatible with the flood hazard of land as at the date the consent authority determines the development application.
- If flood mitigation work is required to enable the development to be compatible with the flood hazard of land, that work should form part of the development application and should be carried out first, prior to the carrying out of the balance of the development. This can be addressed by conditions of development consent.