A Development Control Plan (DCP) contains detailed planning and design guidelines for new development, which need to be considered when preparing a Development Application (DA). It supports and supplements (but cannot override or replace) the provisions in the Local Environment Plan (LEP). It is prepared in consultation with the community.

A Local Environmental Plan (LEP) is the main legal document that controls how land is used and developed in a local government area, allowing Council to plan and regulate growth and development in a sustainable way. It is prepared in consultation with the community and approved by the NSW Minister for Planning.

Both LEPs and DCPs must be consistent with the NSW Environmental Planning and Assessment Act (1979) requirements.

The Flood Prone Land Clause is contained in the DCP. At this stage, there are separate DCPs for each of the former Council areas. A new, single DCP and LEP will be developed for the entire Northern Beaches LGA during the next couple of years.

In August 2017, the flood development controls from the three former councils were harmonised to create a consistent set of controls, so the wording of the integrated Flood Prone Land Clause is already identical in each of the three DCPs.

The clause can be found at:

Pittwater 21 DCP: Clause B3.11

Warringah DCP (2011): Clause E11

Manly DCP (2013): Clause 5.4.3

A review of the current clause identified a number of opportunities to simplify the controls through the rearrangement of some sections into a more logical order, the removal of superfluous text and discrepancies and the incorporation of associated standards and policies into the single DCP clause.

These housekeeping amendments are intended to make the clause more concise, simpler to follow and therefore simpler for applicants. The number of flood prone properties has not changed, nor has the type of information required to be submitted with Development Applications.

Two associated documents, the “Flood Prone Land Design Standard” and the “Flood Emergency Response Planning for Development in Pittwater Policy” are to be rescinded, as well as clause B3.13 in the Pittwater DCP, as all pertinent information from these has now been incorporated into the amended Flood Prone Land Clause in order to create a “one-stop-shop”.

A summary of the updates to the Flood Prone Land Clause can be found in the document 'Summary of Amendments to Flood Prone Land Clause'.

The number of flood prone properties has not changed, nor has the type of information required to be submitted with Development Applications.

The Flood Prone Land clause is only relevant if the property is flood affected and you are planning to develop it such that development consent is required. Generally, the clause applies only to development within the Medium or High Flood Risk Precincts, however for Vulnerable Development such as childcare and hospitals, the clause also applies within the Low Flood Risk Precinct.

You can see whether you are flood affected, and if so which Flood Risk Precinct you are in, on Council’s Planning Maps. Select the “NBC Flood Hazard Map” layer in the “Other Maps” group.

The floodplain has been divided into High, Medium and Low Flood Risk Precincts, based on the level of expected flood risk to people and property, in accordance with the hazard classifications and hydraulic categories as defined in the NSW Floodplain Development Manual 2005.

The High Flood Risk Precinct includes flood prone land in the Flood Planning Area which is: within the floodway; subject to a high hydraulic hazard; and/or subject to significant evacuation difficulties (H5 or H6 Flood Life Hazard Categorisation).

The Medium Flood Risk Precinct includes all flood prone land that is within the Flood Planning Area but not within the High Flood Risk Precinct.

The Low Flood Risk Precinct includes all flood prone land not identified within either the High or Medium Flood Risk Precincts.

The map highlights which property blocks will be affected by flooding. Development controls are applied to a whole property and cannot be split, regardless of flood extent, however, application of the control depends on where on the property the proposed development is located and what type it is.

If there is significant rain at the top of the hill, the rain will run downhill through low lying gullies, channels and surface depressions. Depths may be less at the top of the catchment than further down the hill, but the speed of the runoff is often greater, and flooding may still be significant enough to cause damage.

Application for a Flood Information Report for a specific property may be made using Form 4030 on Council’s website.

You can also contact the Flood Team by email at floodplain@northernbeaches.nsw.gov.au or by phone on 1300 434 434.

Following the public exhibition all community and stakeholder feedback will be reported to Council for consideration, along with any recommended changes to the draft clause as a result of public consultation. Council will then determine whether or not to adopt the proposed amendments.

Any DA lodged before the amended Flood Prone Land Clause is adopted by Council will be assessed as per the existing Flood Prone Land Clause. Depending on the feedback received during the public exhibition process, the final updated clause is likely to be recommended for adoption in late 2020. Any application received following adoption will be subject to the requirements outlined in the revised clause.

A 10.7 Planning Certificate (which used to be called a Section 149 Certificate) is a certificate issued in accordance with Section 10.7 of the Environmental Planning and Assessment Act 1979. It contains information on how a property may be used and the restrictions on development. It is normally obtained when people are buying and selling properties. If a property is known to be flood affected, the 10.7 Planning Certificate will note that flood related development controls apply.

A floodplain is any portion of land which is subject to inundation by floods up to and including the Probable Maximum Flood (PMF) event (or the highest conceivable flood that nature can produce).

The Probable Maximum Flood (PMF) is the largest flood that could conceivably occur at a particular location. It is an extremely rare and unlikely event, however, when managing flood risk within a study area, Council must consider all storm events, up to and including the PMF.

The Annual Exceedance Probability (AEP) is the chance of a flood of a given size occurring in any one year, expressed as a percentage. The 1% AEP flood has a 1% chance (that is a one-in-100 chance) of occurring in any one year.

This does not mean that if a location floods one year, that it will be flood free for the next 99 years. Also, if it has not flooded for 99 years, it does not mean there will definitely be a flood the next year.

Some parts of Australia have received a couple of 1% AEP floods within a decade of each other, and flood events much larger than the 1% AEP flood can, and do, occur (such as the January 2011 flood in Toowoomba).

The Flood Planning Level (FPL) is the height used to set floor levels for houses in flood prone areas. It is defined as the 1% AEP flood level plus an appropriate freeboard (see explanation of ‘freeboard’ below).

It is used for planning purposes, and land below the FPL is considered to be flood affected and therefore subject to flood related development controls. The FPL can be calculated as:

FPL = 1 in 100 year flood level + freeboard (typically 0.5m)

Freeboard is included in the Flood Planning Level as a buffer, to account for factors such as wind, waves, unforeseen blockages, other localised hydraulic effects and uncertainties in the modelling and determination of flood levels. Freeboard is usually 0.5m above a flood level.

Flooding that is sudden and unexpected is referred to as flash flooding. It is usually caused by intense thunderstorms which deposit a large amount of rainfall in a short period of time.

Flood levels, floor levels and ground levels are measured using Australian Height Datum (AHD) as a base, which roughly equates to height above mean sea level. For example, if the floor level of a house is 6.1m AHD and the 1% AEP flood level is 6.8m AHD, the predicted depth of water in the house during a 1% AEP flood is 0.7m (70cm).

Councils in New South Wales have responsibility for identifying and managing flooding, and informing the community. Councils follow the NSW Flood Prone Land Policy, which outlines how Councils should manage flooding to reduce the risk of flooding to people and properties. It also sets consistent guidelines such as using the 1% AEP flood as the industry standard for design and planning purposes. One of the most important steps in this process is increasing our community's awareness of flooding so that people are better able to understand and plan for the flood risks they face.

Council prepares Flood Studies and Plans according to the NSW Government's Floodplain Development Manual (2005), and implements associated recommendations with the financial and technical assistance of NSW Government through its Flood Prone Land Policy. Development controls on buildings in a flood zone are an effective way of protecting life and properties from flood risk. Additional ways that Council manages flooding in the area include installing and monitoring a flood warning network, raising flood awareness in the community, and opening of lagoon entrances to lower water levels.

If it is a life threatening situation call 000.

During a flood, storm or tsunami, please contact the State Emergency Service (SES) on 132 500 or visit their website at www.ses.nsw.gov.au.

The State Emergency Service provides advice on how to manage your flood risk here.