Water Harvesting & Greywater Systems

Rescue Earth System

Rain Water Harvesting can have a significant impact on the amount of potable water a household uses and it can lesson flooding in your area.

Water Harvesting & Greywater Systems

Personal Target: 10 m3 of rainwater harvested annually
Initiative Global Target: 10 billion m3 of rainwater harvested annually
Ultimate Global Goal: 100 billion m3 of rainwater harvested annually

The primary goals of this intervention are:

  • to reduce the quantity of water that has to be chemically treated
  • to increase households resilience to water supply disruptions
  • to decrease the water bills of participating households
  • to provide chlorine free water for watering gardens
  • to decrease storm water run-off from reaching streams
  • to decrease the volume of wastewater that needs to be treated

As you can see from the list above, this simple intervention can have a significant impact on water flows in a watershed, while at the same time increasing a households resilience and reducing its’ expenses. The environment benefits from reduced chemical pollution and less energy expenditure.

Rainwater Harvesting

There are many ways to harvest rainwater, from the really basic DIY to complex systems. The most important question is what you will use the water for. That will determine how much filtration and monitoring it needs, and how complex and expensive your system will be.

A basic system that collects rainwater from a roof via downpipes and a barrel or tank is ideal for watering your garden.

The Water Infiltration, Bioremediation & Cooling intervention, harvests rainwater and stores it underground or in ponds!

Potable Rainwater System

The highest level of complexity for a rainwater harvesting system is to create potable, or drinkable, water. These systems would include filtration, safe storage, pumping, and additional filtering or treatment, as well as additional piping and pumps.

Greywater Recycling

Greywater is a term that is defined by what it’s not, which means that grey water is all kinds of household waste water that is not from a toilet. That includes effluent from kitchen and bathroom sinks, showers and baths, washing machines, and dishwashers. It has fewer potential disease-causing organisms, or pathogens, than toilet water, and so it’s simpler to treat for reuse.

Greywater can be recycled on-site at a home, in an apartment building, office, or a hotel, and it can be used for toilet flushing (after which it’s called black water), garden or lawn watering, or for crops.

Greywater reuse is often designed into a rainwater harvesting system as a way to make the harvested water go farther, as it can be used more than once. For example, harvested rainwater could be filtered and stored, and used first in a shower or washing machine, and then the greywater from those tasks could be collected and used to water gardens.

Using grey water also reduces the amount of wastewater that needs to be collected and treated.

Greywater Recycling for Toilet Flushing:

It is completely unnecessary to use clean drinking water for toilet flushing. Recycled greywater is a perfect alternative for this purpose. Greywater from showers, baths, hand wash basins and clothes washing machine can be reused instead of just being sent to the drain.

Such a system could save approx. 30% of water in an average household. There are a few different recycling options for toilet flushing, preferably treating the water so it can be stored for a certain period, but in certain dwellings where potable water is not required it can be reused without treatment.

It is also great to combine greywater recycling with rainwater which is already fairly clean. It is not recommended to use water that has been in the greywater filtration system for more than 24 hours or bacteria builds up, affecting the water that is being reused, unless treated extensively.

How can I make a difference?

You can choose any one or more of the interventions listed below and your contribution will reduce flooding in your bioregion.

N.B. The standardised financial contribution ERIx10 fee is 100 x the minimum wage rate in your country.

Install a Water Harvesting System

If you would like to go for it alone then this is the best option for you. Installing a 2,400 litre or a 5,000 litre water tank is an easy and cost effective DIY project.

You can use the Permablitz System to get others to help you. The Permablitz System uses the BZ token for transactions via the

Pay the ERIx10 fee or volunteer towards a community water harvesting project

Community water harvesting projects are geared towards installing water harvesting systems on public buildings and those of NPOs. You can pay your ERIx10 fee towards the hardware costs or volunteer 100 hours towards the installation of water harvesting systems.