A number of water utilities have teamed up for an industry-led project that could see intelligent ‘talking’ rainwater tank systems that interpret data, communicate with the Bureau of Meteorology, and take appropriate action, available to Australian homes.
The system was developed by South East Water’s Iota and recently trialled in cooperation with project partner Melbourne Water.
Talking Tanks monitors water levels in a rainwater tank and automatically releases water at a controlled rate if required. The system pre-empts the release of water from set points that are chosen by the user, according to rain or storm predictions which are received via a communications link to the Bureau of Meteorology.
“The system automatically releases water, creates storage capacity and prevents overflows of stormwater – with unique self-learning these intelligent systems are paving the way forward for efficient management of rainwater tanks,” says Business Development Manager iota, Adrian Blinman.
iota forms the commercial arm of South East Water – one of the leading water retailers in Victoria, Australia – which promotes innovative ideas and proven technologies for use across a range of sectors.
“Stormwater can increase the risk of overflow into urban waterways and in some cases carry litter and pollutants or cause erosion. Customers are able to pre-set the required tank water levels and control this remotely through the use of an internet connection or even a smart phone, taking the guesswork out of rainwater management,” said Mr Blinman.
As varying roof and tank combinations react differently to the volume and intensity of a downpour, the software has been designed to learn and self-correct following each rain event. An advanced algorithm was developed to analyse how successful the capture of rainwater was and adjust accordingly for future events.
“With this intelligent technology on board, users can limit the possibility of stormwater overflows and flooding. If rainfall is expected, Talking Tanks will anticipate that draining is required to provide new capacity to capture and hold the incoming stormwater,” said Mr Blinman.
Rainwater tanks have become a valuable tool for the catchment and re-use of rain water, but the tanks also aid in the reduction of the impact of stormwater on drainage infrastructure, roads, urban streams and beaches.
“The application of Talking Tanks on a large scale is an effective measure in prolonging the life of existing stormwater infrastructure or minimising the impact of peak flows on natural waterways that form an integral part of a stormwater network.”
Case Study: Dobson’s Creek, Victoria, Australia
Dobson’s Creek runs through the peri-urban community of The Basin, which is located 31 kilometres east of Melbourne at the foot of the Dandenong Ranges in Victoria. The creek has the highest ecological value within the municipality. However, as with most urban waterways, the health of the creek is adversely impacted by stormwater flows that can carry litter and pollutants or cause erosion.
South East Water wanted to reduce the volumes and the speed with which stormwater enters Dobson’s Creek to help create a healthier, more natural environment.
Project partners South East Water, Melbourne Water, and Knox City Council aimed to reduce the proportion of surfaces that were directly connected to the creek to improve water quality. A system that could shorten these peak stormwater flows within a city environment without the need for huge retention basins was needed. iota services brought together several systems to attempt to resolve this problem in a cost effective way.
In order to ensure tanks were ready to receive rainwater runoff, they may have had to dump some or all of the water contained within them before the predicted rain event arrived. iota aimed to achieve this by employing existing innovative iota products and software that could monitor local weather data and react by a controlled release of water in the tank before the forecast rain event arrived.
A microprocessor linked to a solenoid valve on the tank’s outlet was used to manage the water held by the tank. These units were controlled by South East Water’s SCADA network to which they were linked via a telemetry unit. In addition, the telemetry would monitor local weather forecasts.
Adding complexity to the task, the residential rainwater tanks had dual and conflicting purposes:
to leave space within the tank to capture the peak stormwater event
to retain water in the tank for the resident to use for their own purposes such as irrigation or reuse in the home.
The microprocessor was to only release sufficient water from the tank that would be necessary to capture the forecast rain. A smaller forecast rain event would not necessarily require all the water in the tank to be released. All combinations of roof and tanks react differently to the volume and intensity of a rain event. To account for this variation and to ensure the tank’s dual duties were achieved, the microprocessor’s software algorithm needed to learn and self-correct as it reacted to each rain event. The algorithm detects how successful the capture of rainwater was for each predicted rain event and whether it should change the volume needed in the tank for future similar predicted rain events.
South East Water retained control over these multiple tanks and were able to monitor their performance via the SCADA system. The user would also retain control over the water retained in the tank by allowing access to the SCADA webpage for their tank and an iPhone app that allows control over the tank release valve and set-points.
Monitoring the multiple tanks via South East Water’s SCADA system indicated that they were operating as intended, releasing water before forecast rain events and retaining the runoff during the storm – effectively reducing the peak flow.