Crafers West in the Mt Lofty Ranges is a very high fire risk area… in fact, it’s one of the most high risk suburbs in the state. It’s been a high fire risk area for the three decades that Geoff and I have lived here, and for centuries before that.
It’s legal for me to clear every tree – of any size – within eight metres of my house. It’s legal for every neighbour in my vicinity to do so. My suburb could easily mimic a brand new subdivision on the Adelaide Plains – a sea of tile and iron roofs without a leafy canopy in sight.
Fortunately, that not need be the case. In some instances, it’s possible to have a garden AND a good fire protection system.
About fifteen years ago, Geoff and I engaged reputable professional contractors to install a bushfire sprinkler system on our little (9 squares) house. In other words, our sprinkler system is NOT cobbled together by Geoff, a mate and a few visits to the hardware store for a roll of poly, impact sprinklers and a 3,000L plastic tank. Yet you’d be amazed at how many people entrust their lives and the lives of their families to such systems – just drive around your high fire-risk suburb and I guarantee you’ll see dodgy jobs. It’s insane. If Geoff and/or I plan to ‘stay and defend, we need to be confident that our system will work. This isn’t the time to save pennies and cut corners.
Much as we love our family and friends – even those who are professionally qualified as engineers or as tradies – they are not qualified in fire behaviour and the design of bushfire sprinkler systems. They may be able to determine volumes of water, pipe diameters, etc and even install the system perfectly but, in my opinion, it is completely unfair to place such a responsibility on them, and I’ve reluctantly refused generous offers that would have halved the cost of our system. But even copying a system from another house is no guarantee of effectiveness, because delivery systems must be 100% tailored for your specific house, your specific location and for the unique conditions that fires generate there.
I’ve been told that a large number of cowboys have entered the industry and there’s no certification for installers, so even hiring ‘professionals’ may not guarantee you an excellent system. Do your research and choose a company that’s been in business for many years; ask to see testimonials, or contact your local CFS or SES for their recommendations (the latter is what we originally did). Who better to assess the efficacy of a company’s systems than the people who fight bushfires in your local vicinity?
I’m no expert, so make no recommendation for your garden if you live in a high bushfire risk area. However, I can tell you what we’ve done to balance the desire for a garden and for safety.
Our brick house is single storey with a low profile roof, tucked into a cut and fill site. There’s well-maintained and -inspected sarking under the roof tiles (steel would have been better but we didn’t think of it at the time we built). All unmortared gaps between bricks have been blocked with metal flymesh. Our property faces southwest, with a neighbouring unprotected brick house with a weatherboard second storey about eight metres to the south on the downhill side.
Our boundary plantings include camellias, viburnums and a lillypilly. On the uphill side, a railway sleeper retaining wall with camellias abuts brick paving. To the east is a paved area with water tanks, large potted camellias and a Chinese elm, to the west, a steel verandah with yet more potted camellias and a small lawn. Cliveas edge the verandah. On this side also, high above (but not overhanging) the house are the canopies of two spotted gums, whose lower limbs have been removed.
Some of these features are advantageous, others a risk. A sprinkler system must address all the risks and eliminate or minimise them.
Our system is two-layered with the outer comprising large droplet high-volume water delivered from angled butterfly sprinklers on the eaves, together with inner high pressure sprays to keep walls, doors and windows constantly wet as well. Fittings and pipes are copper, brass and steel, including two-inch copper pipe in some sections – hideously expensive, but no point having sprinklers whose pipes melt just when you need them most.
The 6.5 HP Honda petrol pump, sheltered by a vented cover, draws from >20,000L of water in steel tanks to allow for >90 minutes running time at full pressure; it’s also possible to dial the throttle back to extend fuel time, or further than that until flow is reduced to extend watering time. Two to three hours is the ideal running time, and we will connect more tanks next year to achieve this. When the system is started up, all vegetation around the house, from several metres above the roofline to ground level, is drenched within less than two minutes.
When we had the system installed, I asked whether we should remove all the shrubs – but no. Ironically, in my garden, what is a risk without a sprinkler system, becomes protective with our sprinkler system. The huge surface area created by all those wet leaves (many of them European and of low flammability) creates an outstanding radiant heat barrier – better than lawn or paving in my situation. And all the boundary plantings are saturated, so the house on the downhill side gains protection as well. Houses in other situations may require perimeter sprinklers, impact sprinklers or under-floor sprays.
You can find lists of fire-retardant plants online, and you can avoid highly flammable ones but, in my garden, the flammability of the vegetation is now less crucial than its habit.
There are lots more resources online (the South Australian CFS is just one). Our other bushfire equipment is: breathing masks, goggles, head torches, clothing and knapsacks, with clean beating mops for indoors as well as a powder fire extinguisher. Our carpets are wool with low flammability and fumes.
Our bushfire plan also includes things like bringing the chickens into the laundry. On catastrophic days or those days that have that hot northerly ‘feel’ about them, we lay out the fire hose and fill the bath and a large outdoor drum. Geoff keeps the BBQ gas bottle at his workplace in the city during catastrophic days or heatwaves. If we’re away when a fire starts in our region, we hope but don’t expect that firefighters will start our pump (we have a sign on the front fence that indicates the location of our pump relative to the street). But then we won’t be inside our house, so it’s not essential!
Our street and block have a high concentration of assets and are likely to constitute a line of defence should a fire threaten as it did on the 8th of January 2014.
The day was forecast to be catastrophic, and many of our neighbours (several with babies or toddlers) had already left by the time a fire began in Belair National Park, less than two kilometres from our house. Frustratingly, in their efforts to simplify messages to the public, weather forecast and bushfire warnings no longer indicate a numerical Fire Danger Index, so ‘Catastrophic’ is anything above 100. Our house (and I stress that every house is different) is perfectly defensible at 100, but should forecasts approach 200 as they did during the Victorian fires we would leave. Removing the numerical FDI most disadvantages those like us who intend to defend, and who need the actual number more than those who plan to leave.
On the 8th January, actual conditions did not seem catastrophic, and on Geoff’s smartphone we tracked the approaching SW change and its attendant increases in wind speed and direction as it progressed across the state from the west. We were well-prepared and at one stage walked down to the corner of our almost-deserted street to join a few other locals watching the water bombers. All of these stay-and-defend locals expressed frustration at the lack of a broadcast numerical FDI forecast.
As it turned out when I investigated, the FDI actual for the day was only 46, well below the forecast, largely due to lower than expected wind speeds. I enquired at both the CFS and weather bureau, and discovered it’s possible to ring the Bureau the day before and ask for the actual FDI forecast (the CFS cannot/will not provide it).
So there you have it. I hope I’ve inspired any keen gardeners living in bushfire prone regions, and who plan to stay and defend, to consider installing a professional sprinkler system, or upgrading a home-made one… not least because it may allow you to retain a beautiful garden around your house!