Last week I saw promotion of an initiative to implement waterwise verges, waterwise verge – best practice guidelines throughout the Perth Metropolitan area including in those areas now recognised as being bushfire prone. Unfortunately, this program is likely to have unintended consequences for large parts of the metropolitan area in that it will create a real and ongoing threat of increased fuel load near homes, thus leading to a greater chance of bushfire attack*.
Paradoxically this initiative was promoted in the same week as the release of the Report of the Special Inquiry into the January 2016 Waroona Fire (the Ferguson Report waroona_fires_2016_-_volume_1_-_report_final) which in its findings places a strong emphasis on fuel management.
In this Waterwise program incentives will be offered to householders who will be subsidised to change their verges by a combination of Council and Water Corporation funding waterwise-verge-information-sheet. Thus we see one arm of the State Government, the Water Corporation, offering incentives to change verges to increase the fuel load, i.e. create a fire hazard and another, the Public Sector Commission, in the Ferguson Report, advocating fuel management processes to reduce the fire risk.
For some time I have been concerned about the effects that bushfires may have on communities in Bushfire Prone Areas including in the Metropolitan area. These areas have now been mapped and these BPA maps were released a few months back. They are disturbing in that they show much of the South West Land Division including the outer areas of the Perth Metropolitan area being at risk of bushfire attack. Even areas near the City are shown to be at bushfire risk. I have friends in Glengariff Drive, Floreat who have Bold Park at the rear of their property and they are classified as being in a BPA. See the link for the BPA maps. Developing a verge as described in the Water Corp initiative would add to their fire hazard. http://www.dfes.wa.gov.au/regulationandcompliance/bushfireproneareas/Pages/default.aspx
Thus the release of this verge initiative is concerning for those areas that are quite clearly in areas of bushfire risk. Here is the link to the Page.
The program recommends that in order to save water, householders remove their street lawn and replace it with waterwise plants – the preference is for native plants. These plants are to be kept below a height of 70 cm and preferably are to be non-irrigated.
This treatment of a verge will result in a strip of flammable plant material that is likely to catch on fire and carry a fire toward the house. Embers can be carried hundreds of metres or even more from the main fire. The use of mulch is recommended and its type is not specified – apart from being described as needing to be of coarse consistency. If the mulch is shredded plant material it will act as fuel in a bushfire and add to the risk caused by using fairly dry native plants.
Water conservation is essential, but if water is to be saved, verges in Bushfire Prone Areas, would be best covered, at least partially, by non organic materials including some paving. A small bed of succulents, eg pig face could be added or a small clump of drought-tolerant plants such as geraniums. A shady deciduous tree, such as a Chinese Tallow or Chinese Pistachio, even Prunus or decorative pears (which are quite drought tolerant once established) would be preferable than planting eucalypts or any conifer in BPA. Keeping the verge clear of vegetation apart from some well placed deciduous trees is a viable option. The image of the pears in Kirup is a good example of a practical solution showing a verge at low risk of fire and waterwise.
The select-the-right-tree document referred to by Water Corp includes eucalypts and wattles which are not suitable not only because they are flammable but because they have undesirable habits such as weediness or they are brittle and likely to drop branches or fall over entirely. Flinders Range Wattle is a definite weed and flammable as well. In fact any of the Eastern States wattles are poor subjects for the South West gardens and verges (including the metropolitan area). Balingup, where I Iive, has too many of these trees and they are a real nuisance as they can become large and dangerous. It can cost thousands of dollars to remove them as friends and I have found to our cost.
I have both academic, gardening and first hand experience of many of the trees listed. For some years I did a gardening spot on ABC Local Radio SW. At times I have learnt the hard way when I thought a type of tree was attractive until I discovered it increased bushfire risk, had bad habits and it cost a fortune to remove it.
*There has been an extra section included in the document Waterwise verge – Best Practice Guidelines, Page 6 Additional Section 1.2.8 Bushfire Prone Areas. See waterwise-verge-best-practice-guidelines1