Sustainable sports fields are natural turf not synthetic in a time of climate emergency
Moreland Council intends rolling out synthetic turf when evidence points to it being a highly problematic environmental and climate issue and at a substantially greater lifecycle cost even when factoring in a higher usage ratio.
So it seems the ratepayers of Moreland are going to be hit with expensive replacement costs of synthetic fields every 7-10 years, an increase in urban heat island which will result in health impacts to residents especially during extreme heat events which are becoming more common, an increase in microplastics pollution to local waterways and Port Philip Bay, 274 tonnes of landfill every 7-10 years, reduced abundance of birdlife, and extra greenhouse gas emissions (lifecycle emissions range from 500-1505 tonnes CO2e for synthetic turf) that will need mitigation. (See the Literature Review: Synthetic Turf carbon footprint, environmental, health, microplastics and biodiversity impacts)
“Using compost to amend the soils on sports fields has been shown to improve soil fertility. The amendment of soils also reduces irrigation demand, with benefits to the water industry from water savings and increased resilience to drought. A natural turf field built with a wear tolerant turf cultivar and compost amended soil provides for more liveable cities and gives a superior economic outcome to synthetic turf alternatives.”
Use of compost for sporting fields to increase their fertility, usage capacity and drought resilience is part of the circular economy. It could provide an outlet for Moreland’s green bin food and organic waste collection after it has been through the industrial scale composting process. This is a no-brainer. Moreland Council should embrace this possible reuse of green waste for improving municipal sporting fields.
The research was conducted in the Hunter River region of NSW, a slightly different climate to Melbourne, so the results may be slightly different for sporting fields in Moreland. Moreland Council started on the synthetic sports field path back before 2009 arising from the Millenium drought. I can understand Council taking this direction back then, but I do not think there has been an adequate review or reassessment of possible alternatives since then. Moreland Council has proceeded blindly down a path, with almost pathological determination in negotiation with Sports Clubs and Sporting Federations, rather than be willing to consider alternative paths based on science and information and what was best for all residents, not just the sporting clubs. Currently Hosken Reserve North oval and South oval have a Council recommended 10-15 hours usage capacity per week.
“Amending soil with compost increases the amount of organic matter in the soil profile. This improves the soil structure, increasing its resistance to compaction as well as increasing soil fertility by increasing the soil’s ability to retain nutrients. Fields with compacted soils will not only be harder under foot, but will have a lower water holding capacity. Furthermore, because compost keeps the soil structure open, it increases the ability of the soil to capture rainfall, meaning less water is required for irrigation. The soils of existing fields can be amended with compost by applying the compost to the surface and then mixing (incorporating) the compost throughout the soil profile with a blecavator. The turf surface is then re-established from existing material (if the turf variety is suitable) or a new turf surface is established using an appropriate turf cultivar for the expected usage at the site.“Compost amended fields also have superior water demand outcomes, with water savings of 10-20% compared to those with unamended soils… two sites, one with compost amended soils and the other without. In this case, the water savings from using compost were above 50%.“In addition to requiring less water during normal conditions, fields with compost amendment had superior drought resilience. … The survival watering requirements of the compost amended field are approximately a quarter of those of the unamended site. This has significant implications for the amount of water that is required to sustain green spaces during drought and the volume of demand reductions that could be achieved during restrictions.“Not only does the compost amended field require less water to survive, but it also maintains vastly superior carrying capacity, particularly during water restrictions…. Furthermore, the compost amended field maintained its carrying capacity throughout Level 1 and Level 2 restrictions, with only a 5% reduction in capacity under Level 3.“By contrast, the carrying capacity of the unamended field falls by 20% under Level 1 restrictions, 40% under Level 2 and 60% under Level 3 (no irrigation)…. Under severe water restrictions (no irrigation), the compost amended field can handle 3.5 times as much foot traffic as the unamended field. Hence, by amending sports field soils with compost, the water industry can significantly reduce the social and liveability impacts of drought in urban areas.“A well-built turf field where the soil has been amended with compost and established with a wear tolerant turf cultivar offers superior whole of life cost outcomes compared to lower capital cost alternatives (no compost, cheaper turf) or synthetic fields (Figure 4). When the carrying capacity of each surface is considered, the well built turf field is vastly superior at one third to one quarter of the cost (Figure 5). Furthermore, the well built turf field provides a carrying capacity similar to a synthetic field and up to 2-3 times the carrying capacity of alternative turf options.“From a liveability and heat island perspective, a well-built, natural turf field has lower surface temperatures than a synthetic field, with synthetic fields unusable when the BOM temperature exceed 30 degrees Celsius (Figure 6). This has significant implications for the functionality of synthetic turf surfaces during the warmer months.
“Furthermore, well built turf surfaces provide flexibility for passive recreational and informal community use (e.g. dog walking) that is not possible with a synthetic surface. However, a synthetic surface may be more readily playable immediately following heavy rain during the winter months. That said, a well constructed turf field can be designed to drain rapidly, providing important surface water management measures are implemented (such as sufficient cross fall and avoiding infiltration risks from traditional turf sod).”
Or take for example our neighbouring Maribyrnong Council which is upgrading Skinner Reserve, Braybrook, grass sporting fields :
“The proposed upgrade would involve the redevelopment of the existing field to a high quality grass surface, sand-based oval, comparable to the size and scale of Marvel Stadium…. The improvements, specifically to the quality of the reserve surface, would more than double the amount of time sports clubs are able to use the facility – from the 10-15 hours currently to up to 35 hours per week (in addition to casual use). The Western Bulldogs Football Club would use the space as a second training facility for approximately 12 hours per week over three nights.” (Skinner Reserve – proposed redevelopment, Maribyrnong Council, 19 December 2020)
The current Moreland Council Recreation and Sports Strategy adopted in 2020 has absolutely no assessment at all of climate risks to facilities or people engaged in sports and recreation, or even mention of the urban heat island or climate change. This is a failure in Municipal sports policy given Moreland Council declared a climate emergency in September 2018, with the need for climate risk to be considered in development of all major Moreland municipal strategic policies.