Environmental Considerations

When planning a development there may be environmental factors that need to be taken into consideration. Different factors can apply depending on the location of the development.


BASIX

BASIX stands for the Building Sustainability Index. BASIX was introduced by the NSW state government to make sure new houses or additions are more energy and water efficient.

A BASIX certificate is needed when you lodge a development application for:

  • a new home
  • alterations and additions for an existing home if the work is worth $50,000 or more
  • swimming pools with a volume of more than 40,000 litres

Where do I get a BASIX certificate?

Go to the BASIX website

On the website there’s an online assessment tool you can use.

The BASIX assessment tool calculates if your plans meet the targets for water and energy use. If they do, you’ll be issued with a BASIX certificate.



Water Sensitive Design

We are committed to reducing the impact of stormwater on the health of our waterways by using Water Sensitive Design (WSD).  Water Sensitive Design is an approach to development and re-development that integrates the whole water cycle into the design (stormwater, groundwater, waste water and supply). This approach improves water quality and manages the volume of water leaving a development, reduces our overall demand on water sources and minimises the pollution entering our waterways.

WSD is required for ALL types of development in the MidCoast Council LGA. Currently single dwellings and dual occupancies are exclusive to the former Great Lakes LGA. If your development is in the former Great Lakes your first step should be to check Chapter 11 of the Great Lakes DCP to determine if your proposal or location is exempt.

Checklists, fact sheets, example plans, deemed to comply tables and other tools have been developed to assist with meeting Councils WSD requirements.

How do I know if I need to address Water Sensitive Design?

If you are undertaking development it's very likely that you will need to address WSD. Typically this would include a rainwater tank and a raingarden. Your first step should be to check if it applies to your type of development. The flow chart below (See section 11.1 of the DCP) outlines the steps needed to determine your water quality requirements. The first step is to check the online mapping to see if any requirements have been predetermined for your site. A guide has been prepared to assist with using the online mapping.

If your development is in the former Greater Taree City Council LGA WSD applies to but is not limited to subdivision, commercial developments, industrial developments, manufactured home estates, seniors living, intensive livestock and intensive agriculture proposals or other proposals identified by Council as having a potentially significant impact on water quality of receiving waters.

Flow-chart-of-water-sensitive-design-process.jpg  

Single dwellings and dual occupancies

Once you've determined that you need to address water sensitive design in your DA there is certain information required to be lodged with your DA. The information below outlines the requirements based on whether your proposal falls within a pre-approved strategy area or not.

Pre-approved strategy

If your single dwelling or dual occupancy falls within a new subdivision area that has a pre-approved strategy, then the summary sheet available through the online mapping will list the documents that are required. In some situations you may be required to submit details for a raingarden, in other situations the developer may have dealt with WSD at the subdivision stage and you will only be required to install a certain size rainwater tank. You can check the summaries via the online mapping system.

Sites without pre-approved strategy

If your single dwelling or dual occupancy is not part of a pre-approved strategy, and it is not exempt (as per Section 11.2 of the DCP) you will need to submit full details as part of your application.

For Council to assess your DA properly the following information is required:

  1. Calculation summary of raingarden size showing how it meets the water quality targets (see below for Deemed to Comply and S3QM)
  2. Site Plan showing location of raingarden and all drainage connections (see example site plans below for both clay and sandy soils)
  3. Cross section of raingarden suitable to the soil type of your site (see below for sandy or clay standard drawings)

If any of the above is not provided at time of DA lodgement Council may not accept your application. Additionally if any of this information is missing then it will hold up the assessment of your application until it has been submitted to Council.

Below is a checklist you must use and submit with your DA

Sizing your raingarden - for single dwellings and dual occupancies

The size of the raingarden is determined based on the lot size, roof and driveway areas which drain to the raingarden, and the size of the water tank.

There are two ways to work out what size raingarden you need.

1.  Deemed to Comply Table

Council has developed two Deemed to Comply sizing tables to help size your raingarden. One DTC table is for sites that have access to town water (Section 11.4.1.3 of the DCP), and the other table is for sites that are fully reliant on rainwater (Section 11.4.1.2 of the DCP). This is a simplified sizing methodology that can be used for both clay and sandy soils, provided the criteria can be met. If the criteria for using the table cannot be met, then the Small Scale Stormwater Tool should be used.

2. Small Scale Stormwater Tool

The Small Scale Stormwater Tool (S3QM - www.s3qm.com.au) can be used to gain a more precise raingarden size. It can also be used when the criteria for the Deemed to Comply Table cannot be met or if there are site constraints. A basic guide on how to use the tool can be downloaded below.

Subdivision

Minor subdivisions

Subdivisions that result in a total of 3 lots are only required to submit a drainage plan to identify the applicable targets on the future lots, the capability to construct water quality treatment system and drainage capacity.

Determination of targets can be found in Section 11.4.2.1 of the DCP.

Major subdivisions

Subdivisions that result in greater than 3 lots are required to submit a Water Sensitive Design Strategy (WSD) based on MUSIC modelling. The requirements of the WSD strategy and determination of the water quality targets are outlined in Section 11.4.2.1 the DCP.

Council is currently developing guidelines for MUSIC modelling and Water Sensitive Design Strategies and will be made available in the near future. In the meantime, a checklist has been prepared to assist you in ensuring all of the required documentation has been provided.

For further guidance, please contact Council.

Agriculture

Agricultural developments are required to submit a Water Sensitive Design Strategy. Section  11.4.3 of the DCP outlines the water quality targets and the details required in the strategy.

Other development

'Other Development' excludes single dwellings, dual occupancies, subdivision, agriculture.

Any other development that does not fall within the above categories will need to determine their water quality targets and application requirements based on lot size and existing impervious areas.

For lots smaller than 2500m2 the load reduction targets will most likely be applied. For lots larger than 2500m2 Neutral or Beneficial effect target will be applied and a Water Sensitive Design Strategy will be required.

Full details can be found in Section 11.4.4 of the DCP

Council is currently developing guidelines for MUSIC modelling and Water Sensitive Design Strategies and will be made available in the near future. In the meantime, a checklist has been prepared to assist you in ensuring all of the required documentation has been provided.

For further guidance, please contact Council.

Types of Raingardens

Raingardens can be constructed on both clay and sandy soils and are the most effective treatment available to meet the water quality targets. There are slight differences in the design of raingardens for sandy soils and clay soils and type of raingarden you design for your development should reflect the soil type present on your site.

Sandy Soils - Infiltrating Raingarden

A raingarden that is built on sandy soils is called an 'Infiltrating Raingarden'. This type of raingarden infiltrates into the sandy sub soil and can be built by lining the sides of the raingarden with impermeable plastic and replacing in situ sands with 400mm of filter media. Example site plans and cross sections for an infiltrating raingarden can be downloaded below.

Clay Soils - Raingarden

A raingarden constructed in clay soils contains underdrains that collect and deliver the treated water into the main stormwater system. Example site plans and cross sections for a raingarden can be downloaded below.

Clay sites on steep land

Sites that have a slope steeper than 10% will require a flow dissipator at the inlet to the raingarden. The cross section should also show how the raingarden will be constructed on a steep slope.

Other Water Quality Treatment Options

Swales

Swales can be an option for some large sites where there is enough space and if there are limitations to installing a raingarden

Before investigating the option of a swale, please contact Council to ensure it will be permitted on your site.

Frequently Asked Questions

Water Sensitive Design requirements can be confusing at first. To help you understand WSD and how it is covered in Chapter 11 of the Great Lakes Development Control Plan (DCP), we've produced a Frequently Asked Questions document that you can view or download below.

General WSD Fact Sheets



Contaminated Land Management Policy

The Contaminated Land Management Policy consideration currently only applies to developments in the Gloucester Region.

When carrying out planning functions Council must consider the possibility that a previous land use has caused contamination of the site as well as the potential risk to health or the environment from that contamination.

The purpose of this policy is to establish ‘best practice’ for managing land contamination through the planning and development control process. Download the Contaminated Land Management Policy below.