USGA mix ensures an optimal drainage regime, which encourages deep rooting. The use of high-performance turf soils requires a high level of irrigation to ensure year-round performance of the turf, and specialist advice was sought from Heron Irrigation Consultants.
A multi-region irrigation system was implemented at Paddington Central with fittings by Rainbird that provided drip irrigation to trees and shrubs as well as pop-up sprinkler heads for the lawn arena and terraces. Solenoid valve boxes were hidden from view beneath the Cedec gravel where they can be accessed easily by brushing away the surface and lifting the lid for inspection.
An automatic rain sensor was located on the roof of the cafe, where it is neither obtrusive, rain-shadowed nor vandal-prone.
One particular problem of providing irrigation in areas of hard water is limescale build up. Apart from affecting the performance of drip emitters, limescale can render geotextiles impermeable, resulting in the complete failure of drainage layers.
Historically, acid dosing was the only viable method of neutralising the effect of limescale, but the associated health and safety risk of delivering, handling and storing concentrated nitric acid on commercial schemes has seen a gradual decline in their implementation. Alternative systems for water softening, such as the base exchange unit supplied by Ocas and installed at Paddington Central, use natural salts to neutralise the effects of limescale in the header tank prior to being pumped through the system.