Trickle feed and mixed demand water supply systems
Trickle feed water supply systems add to your existing rainwater supply with water from our supply. These systems come in two types:
a traditional trickle feed system
a mixed demand system.
These systems exist in areas where the water infrastructure may not be able to meet the demands of all users in the area.
A traditional trickle feed system has one connection from our water supply to your water tank. This connection has a valve installed in the water meter that restricts the flow, so that water trickles into your tank. Depending on the set up, your trickle feed system may consist of one or two water tanks (some older properties may have two tanks). It is important to note if you have one water tank, water from the tank will be a mix of town water and rainwater from the roof.
A mixed demand system is similar to a trickle feed system. The restricted flow valve is on the water tank feed line. This system also connects town water to a cold water tap in the kitchen of the home. We recommend using the kitchen tap for drinking water and food preparation. We also recommend connecting one toilet cistern to both supplies (dual feed).
The water in these systems may not be within the Australian Drinking Water Guidelines (ADWG) health limits, due to the rainwater component. Please refer to the Tank water quality section for more details.
Benefits of trickle feed and mixed demand systems
Apart from the environmental benefits of using a rainwater tank, the advantages of a trickle feed or mixed demand system include:
reducing the use of town water, you can always access town water if there is no rain (the restricted delivery rate is about 2 litres per minute)
rainwater tanks can provide a secure water supply to your home in the event of water outages
minimal use of town water means lower water bills.
Parts of a trickle feed system
The following list of components is needed for the correct operation of a trickle feed system:
rainwater tank/s - set up to collect runoff from the roof of your home
water pump and pressure system - sized to suit the owner’s needs
water line - contains taps, fittings, connections and a flow control valve - for mixed demand systems, there will also be a branch for the connection to the cold-water tap located in the kitchen
cistern type inlet valve with an in-tank ball float.
Tank water quality
We treat the water supplied to your tank through the trickle feed system to make sure it is within ADWG health limits.
Water runoff from the roof of your home could contain bacteria or other organisms and contaminants. As a result, your tank water may not meet the ADWG health limits.
You can improve the water quality with regular maintenance of your rainwater tank, pipes, gutters and roof.
For more information about rainwater tank hygiene, please refer to the Rainwater tanks page on our website.
Inlet screens and collection systems
Poor water quality can be a result of:
poor tank hygiene
a lack of maintenance of gutters and insect / leaf screens.
It is important to regularly maintain and clean your water tank, screens, pipes, gutters and roof to improve drinking water quality.
It is also important to check your water tank for build-up of sediments every two to three years, or if there is sediment in the water flow.
Cleaning is easiest and least wasteful when the water level is already low. There are service providers that specialise in water tank cleaning.
To control the level of water in your tank you will need a float valve.
It is important that float valves are correctly set and properly maintained.
an incorrectly set float valve placed in the wrong position may not allow enough water into your tank
if the valve is set too high, your tank may not be able to store much of the rainfall runoff from your roof catchment
if a float valve is worn or poorly maintained, it may not control the inflow of water and result in overflow and wastage - regular checks of your float valve are recommended.
Install a water filter or disinfect water to prevent contamination of household water
The water we supply meets the ADWG health limits.
Once the water supply enters your rainwater tank it may become contaminated. It is your responsibility to make sure your tank is clean and if needed, disinfect the water before drinking or using it for food preparation.
If you are using trickle feed systems for drinking or for food preparation, we recommend you either:
filter the water using a filter which removes bacteria, or
disinfect the water (e.g. boil water).
Water filters and other treatment devices help to remove contamination of your household water by:
removing unpleasant tastes and odours
eliminating harmful germs
removing some chemicals that may be present in your water.
Note: Many filters will only do one or two of these jobs effectively, so it is important to get one fit for purpose.
There are other types of treatment options besides filters, each with certain benefits. Ask your supplier about the different options before you buy a treatment system.