What is a water-sensitive design?

A water sensitive home is one in which the dwelling and its surrounding land are designed and used so as to minimise harmful impacts on the natural water cycle. This includes the consideration of water sources, how water is used and where water flows. It also provides many environmental benefits. The home responds to natural site features, takes advantage of nature’s own water supply (rain), uses water efficiently and helps keep our rivers and streams in good condition. A water sensitive home and design can also save money in the long term.

There are a few ways that good design and planning (including getting a permaculture site report done before you even start to think about house plans) can help map out and plan where water is going to be drawn from, used and flow through your property.  Considering we are entering into an El-Nina cycle and water is going to once-again become a hot topic for Australians, it’s a great time to think about your home or property and how to maximise water use through good design and clever use.

Water use can be minimised via water-saving devices, rainwater harvesting, greywater recycling, compost toilets and lifestyle change. Traditional water supply, stormwater and wastewater practices have been largely based on centralised collection, conveyance and treatment of water flows. Whilst highly effective, these systems also have major drawbacks, such as inefficient use of water resources, environmental degradation and rising infrastructure and maintenance costs. It costs more energy to bring water to your home that it does to do your own collection and use. Easily.

By contrast, water sensitive design emphasises a more decentralised approach attuned to natural environmental processes. It emphases on-site collection, treatment and utilisation of water flows as part of an integrated ‘treatment train’.

Elements in the treatment train may include:

• using roof water for toilets, washing machines, garden watering or even hot water systems
• using runoff or wastewater for irrigation
• infiltrating stormwater to underground aquifers (in areas not affected by urban salinity hazard)
• using specially designed landscaping to cleanse runoff and conserve water.

The water sensitive home requires appropriate responses by designers to each individual site. This means that careful consideration must be given to site characteristics such as soil type, slope, water table, rainfall, salinity hazard and the scale and density of development.

What is water-sensitive urban development?

If you look at the home as part of an ecosystem, then looking at a neighbourhood should also see systems, such as water flows, as a larger ecosystem that has bigger consequences, particularly as we move into periods of greater fluctuation in climate, more intense storms, and longer droughts.

Water sensitive design can:

• Prevent or reduce flooding in targeted locations
• Reduce use of potable water through installing water efficient fixtures and rainwater tanks, and enabling water reuse
• Encourage water to soak into the ground and help plants to thrive
• Protect our natural environment by treating stormwater before it gets to our rivers and harbour

Stormwater management is a fundamental consideration in the planning and design of urban development. Unfortunately, it is often treated as a subsidiary issue that is not addressed until the final stages of the planning and design process. By considering stormwater and drainage issues at the initial design phase it is possible to ensure viable stormwater management solutions that are compatible with other design objectives for the site.

Some of the things you can do at your home to improve water flow and use is:

• Capture rainwater from rooftops before it leaves your property using rainwater tanks, bioswales and rain gardens.
• Plumb rainwater tanks into your toilet and laundry to reduce potable water use

• Slow the flow of stormwater through landscape design, such as placing garden beds along flow paths to utilise this water for passive irrigation.
• Implement landscaping and drainage elements that ensure sediments, leaves, grass clippings and nutrients no longer leave your property. Barrier plantings are one way of achieving this.
• Reduce paved areas and where paving is necessary choose permeable options.

Links:

Build Your own Raingarden http://cooksriver.org.au/raingarden-factsheets/

How to build a raingarden https://offgridliving.net/how-to-make-a-rain-garden-in-your-home-saving-the-rainwater/

Water Sensitive Cities https://watersensitivecities.org.au/water-sensitive-homes-and-buildings/

Low-impact Building https://www.lowimpact.org/categories/building

Water Smart case study https://watersensitivecities.org.au/solutions/case-studies/joshs-house/