Flood Study Update

Storm - Moulder Park - National Avenue Orange - 26 Dec 2010 (Photo - John Kich)

Orange City Council is updating an earlier flood study, which aims to identify areas of potential flooding.

On this site you can :

  • find out more about the study, as well as how and why it was produced
  • learn about the main types of flooding that are being identified
  • look at maps which show the areas of Orange which the study identifies as being potentially affected by flooding.

On this site you can also :

  • find out more about the connections between the flood study and Orange's Planning & Development processes
  • leave a comment, or learn how to make a formal submission
  • ask a question


Orange City Council is updating an earlier flood study, which aims to identify areas of potential flooding.

On this site you can :

  • find out more about the study, as well as how and why it was produced
  • learn about the main types of flooding that are being identified
  • look at maps which show the areas of Orange which the study identifies as being potentially affected by flooding.

On this site you can also :

  • find out more about the connections between the flood study and Orange's Planning & Development processes
  • leave a comment, or learn how to make a formal submission
  • ask a question


  • Residents learn more about flood study at face-to-face forum

    3 months ago
    Flood study q   a session 2




    Orange residents affected by the updated flood study have met with council staff at a face-to-face information session.

    Around 45 people attended a gathering held in the Orange Civic Theatre on Thursday 1 August..

    The event included a presentation about the study, and an opportunity for questions.

    Around twenty residents asked for more information about the study and queried details of the letter that was sent out in late July.

    Residents who attended the meeting were encouraged to continue to ask question online via the YourSay Orange website, or to make an appointment with a council staff member to discuss...




    Orange residents affected by the updated flood study have met with council staff at a face-to-face information session.

    Around 45 people attended a gathering held in the Orange Civic Theatre on Thursday 1 August..

    The event included a presentation about the study, and an opportunity for questions.

    Around twenty residents asked for more information about the study and queried details of the letter that was sent out in late July.

    Residents who attended the meeting were encouraged to continue to ask question online via the YourSay Orange website, or to make an appointment with a council staff member to discuss the flood study and/or the proposed LEP & DCP changes.




  • Council’s updated Orange flood study is open for community comment

    3 months ago
    Map detail 2 300

    Orange Mayor Reg Kidd is encouraging Orange residents to take a close look at Council’s recent updated flood study which was placed on public exhibition this week.

    Council and an independent consultant, Lyall & Associates, recently updated an earlier flood study of the city.

    Orange City Council has sent letters to owners of properties identified on the flood maps.

    Orange Mayor Reg Kidd said it was a vital study, which would be used to plan future housing developments, reduce the risk of floods to existing properties and inform emergency services.

    “The state government requires Council to complete a flood study...

    Orange Mayor Reg Kidd is encouraging Orange residents to take a close look at Council’s recent updated flood study which was placed on public exhibition this week.

    Council and an independent consultant, Lyall & Associates, recently updated an earlier flood study of the city.

    Orange City Council has sent letters to owners of properties identified on the flood maps.

    Orange Mayor Reg Kidd said it was a vital study, which would be used to plan future housing developments, reduce the risk of floods to existing properties and inform emergency services.

    “The state government requires Council to complete a flood study every so often, and the last time Council did this was in 2009,” Cr Kidd said.

    “Since then, Orange has grown quite a lot and it’s important we keep on top of the risk using the latest technology.

    “This study identified the properties at risk, with this knowledge we can now design and lobby for flood improvement measures, such as retention basins, to help reduce that risk.

    “We did just that with information from the last study, and we were able to expand the East Orange channel.

    “The channel expansion project meant there were some properties which were once at risk of flooding, were now no longer at risk.

    “Over the years we’ve also built a network of stormwater management basins across the city to reduce the risk of flooding and to help control sediment flow into our waterways. These include basins at Emus sportsground, one off McNeilly Avenue, Huntley Road, at Kinross Wolaroi School, in Valencia Drive, Kearney’s Drive and Clem Fawn Place and a recently completed one off William Maker Drive and Hawkes Lane to name a few.

    “We are expecting some people may have questions and we’ll be working with residents to understand what the updated study may mean for them and their properties.

    Lyall & Associates started on the study about two years ago but compiled flood maps recently.

    One of the initial steps taken was to survey residents of the existing known flooding areas and to collect historical information and community opinion regarding flooding in the city and drainage.

    The consultant then used the latest technology to measure ground levels of every square metre of the city.

    A plane was flown over the city and an infrared laser was used, called a LiDAR. The laser was used from the plane and was able to measure every change in level with an accuracy of up to 30mm.

    Using this information, existing data and residents’ surveys, the consultant designed a series of maps detailing the probability of flooding in the Orange city from north Orange as far as Industry drive to east at the Northern Distributor Road, south including Shiralee and west to Dean Drive and Spencer Lane.

    Cr Kidd said because the implications of the study could be significant for property owners, the council wants to make it simple to find out more information.

    “The flood study is open for public exhibition and comment and I encourage anyone who has concerns to jump online and look at the draft reports. It has information about the study, frequently asked questions and you can pose your own questions or make a submission,” Cr Kidd said. "The draft report are technical documents but for with anyone with an interest, they are publicly available."

    All documents can be downloaded from this menu.

    “We’re also hosting a community workshop on Thursday 1 August where anyone can come along and ask questions and learn more.

    “The important thing to remember is the study only identifies properties already at risk of a flood."

    The flood study is on exhibition for community comment alongside proposed changes to Orange Local Environmental Plan. You can find out more about the LEP changes here.

  • Is my house listed on the new flood maps?

    3 months ago
    Map detail 300

    Orange City Council is encouraging local residents to find out if their home has been identified on the new maps produced by the updated flood study.

    Here you can access a series of maps (from the links below) showing which areas in Orange are potentially-affected by floods.

    There are two kinds of flooding shown in the flood study maps : Riverine flooding and overland flooding.

    Orange's previous flood study only identified riverine flooding. Areas marked as overland flood zones are being identified for the first time.

    Riverine

    Riverine flooding occurs in the neighbourhood of creeks, waterways and channels where floodwaters...

    Orange City Council is encouraging local residents to find out if their home has been identified on the new maps produced by the updated flood study.

    Here you can access a series of maps (from the links below) showing which areas in Orange are potentially-affected by floods.

    There are two kinds of flooding shown in the flood study maps : Riverine flooding and overland flooding.

    Orange's previous flood study only identified riverine flooding. Areas marked as overland flood zones are being identified for the first time.

    Riverine

    Riverine flooding occurs in the neighbourhood of creeks, waterways and channels where floodwaters could spill over the banks of a creek and inundate nearby areas.

    These areas are marked on the maps in red and are called Flood Planning Areas.

    Overland

    The maps of overland flooding describe areas that can be affected after very heavy storms, when water produced by heavy rain, that doesn’t come from a creek, flows from higher land in a neighbourhood to lower land.

    These areas are marked on the maps in blue and are labelled as ‘Land outside a Flood Planning Area which is subject to overland flow deeper than 100 mm.’

    While residents living near creeks may expect riverine flooding from time to time, the study of overland flooding attempts to analyse and raise awareness of flooding triggered by heavy storms in a neighbourhood.

    Use this map of Orange to select which of the detailed maps to choose from then links below the map..


    Once you’ve selected the individual map which covers your locality, use the ‘Zoom’ menu to focus on your property.

    Map 1

    Map 2

    Map 3

    Map 4

    Map 5

    Map 6

    Map 7

  • Learning more about ‘floor inundation levels’

    3 months ago
    Autumn st garage flooding

    One of the key issues about the updated flood study is the topic of ‘floor inundation levels’.

    The study’s information about ‘above floor inundation’ is complex and residents are encouraged to contact Orange City Council’s Customer Service team to confirm details. However, preliminary information that can assist this process is available here on line.

    Once residents have learnt that their property is within one of the flood zones, the next step is to find out information about the potential depth of floodwater, compared to the floor height of buildings at that location.

    Volume 2 of the flood study ( see...

    One of the key issues about the updated flood study is the topic of ‘floor inundation levels’.

    The study’s information about ‘above floor inundation’ is complex and residents are encouraged to contact Orange City Council’s Customer Service team to confirm details. However, preliminary information that can assist this process is available here on line.

    Once residents have learnt that their property is within one of the flood zones, the next step is to find out information about the potential depth of floodwater, compared to the floor height of buildings at that location.

    Volume 2 of the flood study ( see Document LIbrary section ) includes a number of maps which identify individual properties where the projected floodwater would be higher than the floor of buildings.

    The industry standard for considering planning and development matters is a 1% AEP or 1-in-a-100 year flood.

    In the study, assessments are also made on the basis of a broader range of flood events scenarios ranging from a 0.2% AEP (1 in 500-year) flood to a 20% AEP (1 in a five year ) flood.

    This excerpt from the flood study maps (see link below) shows each area of Orange together with inundated floor heights in the event of a 1% AEP or 1-in-a-100 year flood.

    The coloured symbols identify property locations where flood heights are above floor heights.

    The legend at the side of the map shows the level of the water above floor heights at these locations.

    Download excerpt of flood maps showing, inundated floor heights