Background
New Union Wharf is an impressive, modern residential development located in the heart of the vibrant riverside community of the Isle of Dogs, just downriver from central London and only a stone’s throw away from the city’s central business district, Canary Wharf. The development contains a mixture of apartments arranged in two horseshoe shaped blocks each surrounding large podium courtyards which provide a welcoming, tranquil outdoor space for residents to enjoy. Most of the apartments also boast spectacular views across the River Thames. The development also overlooks the O2 Arena and is located close to a wide range of facilities, shops, and amenities.
The Project
Access Irrigation provided the design, supply, and installation of the complete irrigation system for the development. This included the two large podium courtyards mentioned above, containing planted borders, trees, and lawns, and also included a substantial number of planted borders, trees, and lawns running all the way around the periphery of the two horseshoe shaped apartment blocks.
For efficiency and practicality, the two apartment blocks (each including a podium courtyard and surrounding areas as mentioned) were each treated as separate irrigation systems. These two systems were then both split into several individual, smaller zones – with the system for the first block split into 9 zones, and the system for the second block split into 8 zones.
As the layout of both blocks for the New Union Wharf irrigation scheme were similar, they each conveniently contained a ground level plant room to house the pump and tank units required to boost the water pressure. The 100 litre capacity tanks supplied (one for each block) ensured that both systems complied with the Water Regulations regarding backflow prevention, by including a Type AB air gap at the top of the tank wall below the tank inlet, to prevent backflow into the public mains if a fault developed. A float switch was also fitted inside the tank to protect the pump against running dry, by ceasing the watering cycle when the water level becomes too low, thereby allowing the tank to refill before watering recommences. The pressurised supply to both systems was provided by a compact Lowara BG Series pump (one for each block) featuring a stainless-steel body and motor shaft for long life.
A sophisticated Heron Mi controller was included to automate the system, this controller having a large digital display for easy, accurate programming
and a very high level of reliability. The controller also boasts a permanent memory to conveniently ensure that programmed watering schedules are never lost if there is a power failure. To prevent the system operating in wet weather, and to prevent water wastage and potential damage to the plants, a rain sensor was included. The sensor is adjustable so that watering can continue to be prevented even after a pre-set quantity of rainfall, as the sensor dries out at a similar rate to the planting and then automatically re-sets itself once it has dried.
The individual zones were programmed to operate at different watering times and durations, depending upon planting watering requirements, to enable efficient, managed watering for each zone. Hunter PGV solenoid valves were included for this purpose – one valve operating each zone, being opened in sequence by the irrigation controller. The valves also include flow control adjustment and manual override for emergency operation. They were housed inside underground valve boxes located within the soft landscaping, these valve boxes being fitted with vandal-resistant metal covers for protection. Underground MDPE supply pipe ran from each pump and tank unit to the valve boxes comprising each system, with this pipe then also running to the planted borders, trees, and lawns.
Highly efficient Permadrip Pro Dripline was used to water the planted borders and trees. Permadrip-Pro is a brown coloured dripline designed for landscape irrigation with a 16mm pipe diameter and a wall thickness of 1.2mm. The 1.6 L/h drip emitters are pressure compensating, ensuring uniform output over a wide pressure range and include a built-in anti-siphon mechanism, to prevent dirt being sucked into the drippers at the end of the irrigation cycle. The emitters also have a large inlet filter and unique, continually self-cleaning design, providing excellent resistance to blockages. Dripline including dripper emitters spaced at 50cm intervals was used to water the planted borders, and dripline including dripper emitters spaced at much closer 15cm intervals, for very thorough watering, was used to water the trees. Anchorage pegs were included to hold the dripline securely in place, with stopends being used to terminate the water flow at the end of each dripline run.
Advanced Hunter MP rotator popup sprinklers were used to water the lawn areas. MP rotators emit water with multi-trajectory rotating streams, giving excellent uniformity, matched precipitation at any arc or radius, and low application rate to reduce run-off. The sprinklers have a range from 2.4m to 8.2m, making them ideal for watering small to medium lawn areas, like those included here. Hunter popup sprinklers are renowned for their quality, and feature a ‘top-down’ design, which allows all servicing to be carried out from above – preventing damage to the lawn.
The Installation
Our experienced engineers were responsible for the installation, testing and commissioning of the complete irrigation system at New Union Wharf. This was carried out in phases according to actual site conditions and the program of works. Once the installation was complete, we provided the client with full instructions on the operation and maintenance of the system.
The Result
Our New Union Wharf irrigation project has resulted in green and lush communal spaces for all residents to enjoy, providing the perfect place to socialise, relax and de-stress, whilst also substantially boosting biodiversity, and enhancing the development. We are delighted with the result and are proud to play our part in helping a modern, global city like London to develop and thrive.
