Overland Flow Update


Most people who live or invest in Brisbane will have experienced the rains and subsequent flooding and overland flow that resulted earlier this year. Most of you will also be aware that as a result of the deluge the Brisbane City Council have announced a new overland flow mapping system so that owners and buyers can be better educated when it comes to overland flow.

What is overland flow? 

Here is a reminder of what overland flow is. In its simplest form, overland flow is water that flows down towards a low point or water source whereas flooding is water that rises from a water course. Overland flow can occur to varying degrees in any significant rainfall. Want proof? Take a look at the water running down your concrete driveway in the next downpour. This isn’t the overland flow we are concerned about, however. The overland flow that really affects property owners and what they can achieve on their property in terms of development is concentrated overland flow that follows low points and gullies.

Almost every property that contains a low point or is in some form of gully has need to be concerned about overland flow.

A new mapping system for Brisbane

Brisbane City Council are currently working on a mapping system that will quickly and easily inform the public which properties are affected by severe overland flow and therefore may be restricted in what they can develop on their site.

This is both a blessing and a curse, but may create opportunity.

The curse 

It may well be that you are currently in an overland flow path and not know it. A highly experienced investor may be able to pick up on this, but for now the general public are unlikely to. For that reason this mapping system could be a curse for those owners. If the majority of people aren’t aware that you are in an overland flow path, and then overnight with the release of this new mapping system the majority now know you are in an overland flow path, then your property value will suffer.

Another potential consequence is how insurance companies treat properties formally identified in overland flow paths.

The blessing 

The blessing of course is with this new system there is now less risk for buyers.

The opportunity? 


The opportunity? It may well be that some properties appear in this system that aren’t heavily affected, or through clever design a developer can largely mitigate the effect of the overland flow, which means they may well pick up a bargain.

To illustrate this point, flood data is often available for properties in Brisbane that may look bad, but in fact it could be just one small portion of the site is affected, being the low point in the corner of the backyard. The rest of the site may be built up and there are no effects on how you develop the site.

Knowledgeable investors have long known about overland flow and while information on what is affected hasn’t been readily available in Brisbane, they have been able to assess the likelihood of overland flow themselves.

Regardless of whether you are knowledgeable in this area or not, you need to understand overland flow and how to read a property and plans to assess the likelihood of overland flow and this doesn’t change even with the introduction of the new mapping system.

To read a related article click here.

How to reduce risk 

Investigate Property carries out extensive research on every property they source for clients, including research into overland flow. If you want to minimise risk when buying then you should employ Investigate Property.

You should also educate yourself extensively prior to purchasing any kind of investment property. At Developing for Profit the Development A-Team (13 guest speakers) will educate you on every aspect of developing residential property, including how to research and what to research. This is a must attend event for any aspiring developers or people already developing but know they can do it better. Click here for more information.

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