GREEN OASIS

Deep within the basement there is a dedicated irrigation control room, reminiscent of a mad scientist lab, which houses the brains of the system which monitors, feeds and waters the 1200m² of green walls and 4200m² of garden beds housed in 2600 individual planter boxes.

Design Landscapes Pty Ltd was engaged under a design and construct contract to take the concept through design development and 190 shop drawings prior to on-site installation works commencing.

The irrigation system not only waters the facades of the East (33 levels) and West (17 levels) towers but also covers the building lobby, surrounding landscape podiums, terraces and French Stairs which lead down from Chippendale Green into the retail precinct. Water is drawn from the dedicated blackwater treatment plant with bypass connections to potable water in case of breakdown or lack of sufficient treated water being provided.

Two dual pump sets (one for green walls and one for planter boxes) provide 18,000kPa each of head pressure, necessary to pump water up the 33 storeys with a single duty pump for each set being operational and a back-up standby pump. Adjacent to the pump sets are the four fertigation injections pumps (one per mainline) which inject both liquid fertiliser and other nominated herbicides/chemicals into the irrigation mainline. Each unit is calibrated to provide precisely dosed volumes of fertiliser to suit either the green walls or the planter box plant material.

Design Landscapes’ in-house hydraulics team installed a maze of specially manufactured high pressure lines consisting of 75mm mainlines running through internal building risers, 19 kilometres of 25mm lateral lines running through the apartment walls and ceilings and 27 kilometres of drip lines to the individual planter boxes and green walls. Each of the 23 green wall panels has a different configuration of lateral lines and drip emitters with each line (up to 10 per panel) being switched via a separate solenoid for maximum control. Each line is then set to different run durations so that the whole of the wall receives an equal volume of water.

The control system utilises an off the shelf program, however, due to the 270 smart decoder electrical solenoid valves required, the system selected was one typically utilised in the golf course irrigation. Performance amendments were required to the core programme and the system recalibrated in conjunction with installation of flow control sensors so as to be able to interpret the significantly lower level of water flows. Whilst the control system provided many of the specified parameters such as control from the buildings central BMS, ability to send alarm via text message, evapotranspiration sensitivity, full remote real time monitoring and amendment capabilities and high flow alarms, it did not have the ability to notify of low flow events. For this, a secondary alarm system was installed that undertakes this single task of remote alarm notification of a low/no flow event.

In conjunction with the D&C contract for the irrigation system Design Landscapes was also engaged under separate contract to supply and install the 2100m³ of specially blended soil and to install the 55,000 plants. The irrigation system and the soft landscaping were installed continuously, so as to ensure that the many inaccessible areas were able to be watered from the first day of planting.

For more information, please contact Design Landscapes:
Ph: 02 9958 9400
Email: sales@designls.com