Demand and capacity

Chapter 4 of the Natural Grass vs. Synthetic Turf Surfaces Study Final Report,

Sport participation trends and demand

A key component of determining whether to use natural grass or synthetic turf is the demand for the use of the surface.  The seven sports included are either main stream sports in Western Australia or are an emerging sport i.e. rugby union. The Commonwealth Government, in conjunction with the State and Territory Governments, prepare participation data for a range of sport and active recreation pursuits on an annual basis.  This is known as the Exercise, Recreation and Sport Survey (ERASS).  ERASS provides participation numbers and rates for a range of sporting activities at national and state levels.  Table 1 below highlights the participation levels and rates for each sport in Western Australia from 2006-2010.

Participation in cricket declined in 2007, increased in 2008 before declining again in 2009 and 2010.  Australian Rules football tends to be cyclical decreasing in 2007 and 2009 but increasing in 2008 and 2010.  Hockey has been increasing in popularity up until 2010 when it dropped off significantly.  Lawn bowls has been increasing in popularity from 2006-2010.  Rugby union participation like Australian Rules is cyclical.  Soccer has increased significantly in popularity from 2007-2010.  Tennis declined initially and then increased in 2008-2009 followed by a decrease again in 2010.

This highlights the dynamic nature of sports participation and the need to understand the fluctuations that can occur within individual sports. In addition to statewide trends local factors such as facility provision, club management, availability of volunteer resources, local demographics and marketing techniques all impact on participation rates, and need to be considered when determining the preferred surface type.

Table 1: ERASS Participation Data for WA 2006-2010

Sport played

2006

2007

2008

2009

2010

‘000

%

‘000

%

‘000

%

‘000

%

‘000

%

Cricket

50.3

3.1

36.3

2.2

58.6

3.5

49.4

2.8

39.0

2.2

Football - Australian Rules

82.3

5.0

48.8

3.0

73.0

4.4

68.4

3.9

96.8

5.4

Hockey

25.2

1.5

28.2

1.7

37.2

2.3

41.7

2.4

24.3

1.4

Lawn Bowls

33.5

2.1

33.2

2.1

33.7

2.0

39.9

2.3

41.4

2.3

Rugby Union

7.2*

0.4*

12.8*

0.8*

10.6*

0.6*

15.1*

0.9*

5.9*

0.3*

Soccer

59.3

3.6

48.8

3.0

73.0

4.4

70.7

4.1

82.6

4.6

Tennis

97.4

6.0

72.0

4.5

90.5

5.5

94.6

5.4

87.1

4.9

Natural Grass Sports Ground Capacity

The capacity of a natural grass sports ground is the maximum level of traffic/usage that the site can sustain without resulting in a major decline in the turf and surface condition that renders the site ‘unfit for use’.

When assessing the capacity of a sports ground two principal considerations are asset management and player safety.

  • Asset management refers to the condition of the asset or the sports ground, and in particular, the condition of the turf and surface in relation to the desired condition and intended use.
  • Player safety refers to the standard or quality of the turf and surface that is required to safely undertake a specific activity on the site.

Given sports grounds are used for diverse activities and levels of sport, the asset management and player safety standards will vary depending on the activity. It is not necessary for elite sports standards to apply to local level sports grounds.  All sports grounds should be maintained to a ‘fit for use’ standard to minimise the risk to users.

The factors that directly impact on the capacity of a sports ground include;

  • Sports Ground Condition
    • Grass species and quality
    • Surface quality
  • Weather Conditions
    • Temperature
    • Rainfall
  • Type of Usage/Sporting code
    • High Impact (e.g. Football/Rugby)
    • Lower Impact (e.g. Cricket/Athletics)
  • Level of Usage
    • Number of registered teams
    • Competition games
    • Training schedule
    • The level or age range of users

Natural grass sports ground condition

When sports grounds are under stress from either, poor nutrition, weed or disease infestation, or compacted soil, turf health and density will be poor. When this is the case the surface will become unstable and unable to withstand ongoing wear from usage. 

Weather conditions

The weather has a significant impact on the natural grass quality and its ability to recover from wear. Temperature affects the growth of natural grass with warm season species actively growing in the summer months and cool season species peak growth in spring and autumn.  All grasses have reduced growth in the colder winter months with lower recovery rates.

Rainfall also impacts on the wear of natural grass. High rainfall events, in conjunction with high usage, result in deterioration of the soil structure and excessive wear on the natural grass. This is particularly the case in heavy soils during the winter months, when the natural grass growth and recovery is minimal. Where sports grounds are constructed with either natural or imported sand profiles with high drainage rates and/or subsurface drainage the ability to remove excessive water is increased with a corresponding reduction in natural grass wear.

Rainfall occurring in the colder winter months has a potential high impact on the capacity of the ground particularly where high impact sporting activities such as football ( AFL and soccer ) are in season.

Type of usage

Different activities have a varying impact on the natural grass surface. Football (soccer) and Australian Rules football are high impact sports with high wear on the centre corridor of the ground.  Rugby and hockey, whilst being high impact sports, are spread across the ground and therefore have less impact.  Cricket is a lower impact sport with less intensive wear across the ground with the exception of the centre wicket, which has high wear due to the intensity of activity in this area. 

Level of usage

The level of usage is one of the main factors which impact on the condition of the natural grass surface of a sports ground and the subsequent capacity of the ground to provide a safe, ‘fit for purpose’ facility for community sporting activities.

The number of registered teams, competition games and training schedules will impact on the natural grass and surface condition of a sports ground. Issues such as significant deterioration of natural grass quality lead to bare areas and a reduction in surface quality that may, in extreme cases, render the ground ‘unfit for use’ and result in ground closures or restricted usage.

The number of participants and the number of games held on the site impact on the level of wear of the natural grass. Training also has a significant impact on natural grass wear, particularly where it is concentrated in localised areas of the ground.  The level or age range of users also has a varying impact on natural grass wear. For the same activity senior teams tend to have a greater impact than junior teams.

Work has been done in developing benchmarks for sports ground usage using the ‘IPOS – Sports Ground Usage Model’. Using data in relation to the number of competition games and training schedules, usage rates are determined on the basis of “person hours per week”.

Different sporting codes and venues have different playing field sizes which result in varying wear impacts. The same number of person hours usage will have a higher impact on a smaller playing field.  In order to standardise information so that comparison can be made for different sporting codes and venues the measure or ‘Sports Ground Usage Index’ used to assess sports ground usage is ‘metre square per person hour per week’ (m2/phr/wk).

This criteria has been developed as it reflects the number of hours the ground is used, the number of persons using the ground per week and the size of the field. It also provides a standard measure or ‘Sports Ground Usage Index’ that can be compared across sporting codes and for various sized sports grounds.

Benchmarks have been developed for football (AFL and Soccer) as follows.

Table 2: Sports Ground Usage Rate Benchmarks - Football (AFL)

No of Teams

Sports Ground Usage Rates
(Adj Person Hr/week)
( AFL - 16,000 m2 )

Sports Ground Usage Index

(m2/Person/hr/week)

( AFL – 16,000 m2 )

Usage Comment

> 5 Jnr / 5 Snr

>750

<20

Extremely High

5 Jnr / 5 Snr

450 - 750

21 - 35

High

4 Jnr / 4 Snr

300 - 450

36 - 50

Moderate

3 Jnr / 3 Snr

200 - 300

50 - 70

Moderate - Low

2 Jnr / 2 Snr

< 200

> 70

Low

Table 3: Sports Ground Usage Rate Benchmarks - Football (Soccer)

No of Teams

Sports Ground Usage Rates
(Adj Person Hr/week)
( Soccer - 7,000 m2 )

Sports Ground Usage Index

(m2/ Person/hr/week)

( Soccer - 7,000 m2 )

Usage Comment

> 5 Jnr / 5 Snr

> 350

<20

Extremely High

5 Jnr / 5 Snr

200 - 350

21 - 35

High

4 Jnr / 4 Snr

140 - 200

36 - 50

Moderate

3 Jnr / 3 Snr

100 - 140

50 - 70

Moderate - Low

2 Jnr / 2 Snr

< 100

> 70

Low

Sports ground usage and capacity measures are indicative only and can be used to compare usage levels and capacity between sports grounds or to determine management strategies for a given venue.

There are many variables that may further impact on capacity that may be unknown or not measured. These include the impact of:

  • unstructured community use;
  • unauthorised structured use;
  •  intensive localised training under lights and near the club rooms; and
  • intense rainfall events.

There will always be a need to inspect, monitor the performance of the sports ground and liaise with the sports club or association to ensure that it is ‘fit for use’ for the designated activity.

Further information regarding Sports Ground Usage and Capacity Measures is available at www.ipos.net.au