Nearly 90 HDB blocks in Yishun and Jurong to be installed with rainwater harvesting system
SINGAPORE: Nearly 90 Housing Board blocks in Yishun and Jurong will be installed with a system in the coming years to harvest rainwater for non-potable uses at the common areas.
This is the first time that the UrbanWater Harvesting System (UWHS) will be installed in existing housing estates, said the Housing and Development Board (HDB) on Monday (Mar 28). Previously they were rolled out at suitable new Build-to-Order (BTO) projects.
"Unlike in new BTO projects where the UWHS infrastructure can be planned and designed upfront to ensure it is located where the most amount of rainwater can be collected through the drain networks, retrofitting the UWHS into existing estates is more challenging," said HDB.
This is because it involves analysing the flow of the rainwater in the catchment area and identifying suitable locations to place the system amid other essential services infrastructure.
The pilot project in Yishun and Jurong will cover 89 blocks.
HDB said the systems would potentially reap 17,500 cubic metres of water savings per year, or the average yearly consumption of potable water of over 85 units of four-room HDB flats.
The tender for the project was called on Monday. It will close on May 20, with construction expected to take place between 2023 and 2027.
"HDB will study the cost-effectiveness of the system in reducing potable water consumption and mitigating flood risks in existing HDB estates, before deciding on the extent of future scale-up to other suitable estates," the agency said.
The UrbanWater Harvesting System, first introduced in 2018, is designed to maximise the volume of rainwater collected by harvesting stormwater surface runoff from the ground area surrounding multiple residential blocks, said HDB.
Stormwater is channelled to a harvesting tank, before being pumped into a treatment room.
A single UWHS can harvest and dispense water to as many as 12 residential blocks for non-potable uses such as washing common areas and watering plants in HDB estates, said the agency.
"In addition, the channelling of stormwater into the UWHS’ harvesting and detention tank can mitigate potential flood risks in an estate in the event of a heavy downpour, by slowing down the rate of discharge of stormwater into the drainage system downstream," HDB added.
SOLAR PANEL INSTALLATION
HDB is also progressing with its solar panel projects under the SolarNova programme, awarding the sixth tender for the installation of solar panels at 1,198 HDB blocks and 57 government sites.
The tender was awarded to the joint venture of Digo Corporation and Terrenus Energy, said HDB on Monday, noting that there were six bids from both local and foreign companies.
Installation of the solar panels is expected to begin in the third quarter of 2022 and be completed by the first quarter of 2025, reaping a solar PV capacity of 70 MWp, said HDB.
The agency has put out a total of seven solar leasing tenders under the programme, with the latest called in February.
"HDB has committed a total solar capacity of 380 MWp or equivalent to powering 95,000 four-room flats with solar energy, bringing us a step closer to realising our solar target of 540 MWp by 2030," said the agency.
Editor's note: This story has been updated after HDB corrected which blocks will have the UrbanWater Harvesting System installed.