Case study looking at how a Wellington City Council (WCC) artificial turf project transformed a playing field.

Overview

Visit Nairnville Park in Khandallah and you’ll find a playing field with artificial turf - just the third such surface in New Zealand. Chances are, even in the wet, it will be busy with football or rugby players because with its new surface, usage has increased exponentially.

The $900,000 WCC project is a good example of how artificial turf can transform a playing field. But perhaps the best indicator of success is that the council now plans to lay artificial turf at other fields around the capital. In fact, one more has already been completed.

In May 2010, a second artificial sports field opened at the former Wellington Showgrounds site in Newtown. The council is planning to build two additional artificial sports fields at Wakefield Park before the 2011 winter. Three additional fields are planned for construction between 2013 and 2018.

Background and partners

WCC sports fields are under significant pressure. The city has a relatively high rainfall – an average of 1246mm a year. Soils are predominantly clay. Almost a quarter of the fields sit on old landfills and are often poor draining and prone to subsidence.

The pressure is escalating. There’s increasing demand from sports groups, particularly football, which has had a boom in participation. Recent years have seen more sports events held and significant growth in professional codes.The city’s population has grown from 157 719 in 1996 to 179 466 in 2006 – up 13.8%. Also, greater overlap of the winter and summer seasons means there’s often now little time for fields to recover and have rehabilitation work.

"Sports fields around the city are being used above their maximum sustainable usage", says Glenn McGovern, the council’s sports and recreation planning manager. "Winter is a real pressure point. Ground closures regularly occur."

During the very wet Wellington winter of 2010, for example, some football and rugby youth grades had around half their games and training cancelled. Senior fixtures were also significantly affected. "That caused a lot of frustration for players, organisers, spectators and volunteers", McGovern says.

The council first invested in artificial sports surfaces more than 25 years ago, with Newtown Park athletic track and Mt Albert hockey stadium. Artificial surfaces for netball and tennis were installed at Haitaitai in 2002. "We have a long history of using artificial surfaces – but not for rugby and football", he says.

Around the world artificial turf is booming – since the start of the millennium, Europe’s seen more than 5000 such surfaces installed for football alone. It is now common in Korea, Japan, Hong Kong, North America and Australia. The only other artificial turfs large enough for competition games in New Zealand in mid-2009 were at a New Zealand College Rifles field in Auckland and North Harbour Stadium.

Artificial turf can sustain far greater use than a soil or sand-based field. It can also be played on in most weather conditions. The Wellington Rugby Football Union and Capital Football made submissions in favour of artificial turf fields in the 2008/09 WCC Draft Annual Plan. In 2008, the council began planning a solution for Nairnville Park.

The park was seen as an ideal location to pilot artificial turf. It’s a community sports hub, with a busy recreation centre and a number of fields. The field had suffered from poor drainage for decades. As McGovern recalls: "I was sent a letter from a former All Black, Brian Steele, who played there in the 1930s. He said that it was a mud heap back then, and it’s a mud heap now [before the artificial turf]".

The condition of the Nairnville field meant it was poorly utilised. On average the field was only used for about six hours per week for rugby training between April and August. The Wellington Showgrounds site was previously an under-utilised carpark. Converting them into high capacity fields would maximise the benefits of the council’s investment.

The initiative

The Nairnville project was publicised during the planning stages. Some residents expressed concern (due to visual impact) about the proposed perimeter fence. An agreement was later reached to trial a fence-free field for 12 months.

Modern artificial turf is made of polyethylene – it’s nothing like the older style nylon surface, which resembles a pot scrubber and can lead to abrasion burns. The modern turf has 65mm long fibres, which appear almost the same as natural grass. "It’s hard to tell the difference, even when you’re standing on it", says McGovern. A 25mm thick rubber shock pad sits under the Nairnville turf. On top are layers of sand and rubber granules, leaving only the top 15-20mm of the fibres showing. The Wellington Showgrounds’ turf is similar without the rubber pad.

New floodlighting was constructed for both sites to maximise usage – there is no resource consent required for use up to 9pm at Nairnville and 9.30pm at the Showgrounds, seven days a week.

"We were very fortunate to gain $500,000 in funding from the New Zealand Community Trust for the Nairnville field. Council funded the balance. Capital Football funded the goalposts", McGovern explained.

Main benefits

While it’s too early to assess the long-term performance of the artificial turfs, immediate results have been excellent. "We’ve had nothing but positive feedback", says McGovern. As he notes, players, event organisers, clubs and the council all benefit.

Enhanced usage and reliability

The turf can be played on in rain. "We put a lot of work into the drainage", McGovern says. In contrast to before the turf was installed, both fields are now used for an average of 60 hours per week during the winter months. One of the most successful outcomes has been the development of the Capital Football under-12 girls’ league. The league started in 2009 at the Nairnville artificial and attracted 37 teams. In 2010 the girls’ league has expanded to 63 teams, and because of its size is now played on both Nairnville and the Showgrounds sports fields.

Durability

The sand and rubber should only require weekly grooming. The turf itself has a predicted lifespan of 10 to 15 years.

Player safety

With 100 tonnes of sand artificial turf offers a consistently forgiving playing surface – it’s much softer than a hard-packed summer ground. The polyethylene grass has a slightly greasy texture and, as McGovern says, "We’ve had no reports of grass burns".

Reduced maintenance cost

Because of the higher upfront investment, artificial turf has greater depreciation cost than a natural grass field. However, McGovern notes that ongoing maintenance costs are expected to be "significantly reduced".

The estimated construction cost of a full-sized 3G turf is presently $1.5 million, including floodlighting. The estimated maintenance cost is $5,000 to 10,000 per annum. According to research, the estimated total cost of constructing and maintaining an artificial turf over a 10-year period is approximately twice that of a sand-based grass field. However, an artificial surface is able to cope with five to six times the usage of a typical natural grass field. The net cost per hour of use for an artificial surface is much lower than a sand/soil-based field if this level of use is achieved.

Looking ahead

The Nairnville Park and Wellington Showgrounds artificial sports fields have been highly successful in providing much needed facilities for training and competition for a wide array of sporting codes. The all-weather nature of these fields has been extremely valuable in meeting demand during the wet winter weather.

Building on the success of these two grounds, the WCC plans to build two more artificial turfs at Wakefield Park. The draft Long Term Council Community Plan includes funding for three additional artificial sports fields across the city. The Wellington Rugby Football Union and Capital Football have made submissions in support of at least 10 artificial turf surfaces.

As McGovern concludes: "Growing grass on fields that are over-utilised in Wellington’s climate is a constant challenge. Having more artificial turf fields would result in greater capacity for training, competition, events and recreation programmes – plus it would make caring for the grounds a lot easier. Artificial turf is a boost for Wellington all round".