A selection of new garden beds in Robert Street Marrickville

We came across new footpath work in Robert Street Marrickville yesterday.  Marrickville Council has replaced the footpaths & created large garden beds around street trees planted on verges.   It’s happening in other streets so it appears to be a new trend.  I sincerely hope so.

The first time I saw this done was earlier this year in Ivanhoe Street Marrickville South & I was impressed.  The garden beds are twice as large in Robert Street because the footpaths are wider.

As well as the street trees on the verge, Robert Street has beautiful old Brush Box trees that were planted on the sides of the road around 80 years ago. Council has created garden beds on the verge next to many of these trees, which will allow these trees to be able to get a good drink when it rains.  These trees have suffered decades of bitumen almost to their trunks so they should respond well & live longer now they have better access to water.  Council have planted native grasses & Pig Face (I think) & in a year or so, they should look very pretty.

Unfortunately, works like these can cost many thousands of dollars (a tiled footpath outside a small group of shops can cost $60,000) so I would imagine that it would be a slow process creating these types of footpaths as the norm throughout the LGA.  However, it’s worth waiting for.

It is good that by creating these garden beds, the amount of cement coverage has lessened. Not only will the trees get more water & the streets look greener, but the street should be cooler during summer as well.

Is less cement an issue? I think it is & so do many experts.  Urban areas are much hotter than non-urban areas because cement & building surfaces can trap heat from the sun.  This is called the ‘heat island effect.’

The flying foxes that left Queensland to come & live in Sydney’s Royal Botanic Gardens for the past 20 years or so have made their home there because the air temperature is to their liking.  The walls of the tall city buildings, roads, cement surfaces & roofs of the CBD have raised the air temperature & created a climate suitable for the bats. In the city it is called the urban canyon effect because the walls of tall buildings form canyons that capture & hold heat.

Air temperatures can be up to 12 degrees hotter in cemented areas during summer. I have read up to 50 degrees hotter, but this is probably in desert areas.  Much like a car parked in the sun with the windows closed, environments can become heat boxes keeping night temperatures warmer. A 2005 study showed urban air temperatures being up to 12 degrees warmer at night during summer than in rural areas.

Apart from the obvious increase use of power needed to cool houses & the associated costs, the heat island effect also impacts on air quality & health as it causes smog & ground level ozone. Ground level ozone causes respiratory problems like asthma, coughing & lung damage. It can also cause chest pain & heart problems.  This is why research shows that living within 500 metres of a main road can cause significant health problems.  See – https://savingourtrees.wordpress.com/2010/06/29/living-close-to-a-main-road-is-bad-for-your-health/

Ground level ozone is also a factor in global warming.  The heat island effect can raise the temperature so much that it causes heat events where heat waves are exacerbated. These events can cause death, particularly in children, the ill & the elderly.

There is also another issue with the heat island effect & that is storm water runoff.  If the runoff is heated by pavements, gutters & roofs, it may be very warm by the time it reaches rivers, ponds & lakes & we have a few in Marrickville LGA.  This hot water can cause death to fish & other water life as well as increase the growth of blue-green algae that sucks all oxygen out of the water causing more fish death.

This is a very basic outline of the heat island effect & I will be writing about it in more depth in a later post. However, I hope what is written so far is enough to understand why our society’s love for cement is a problem.  Cement is easier, but it comes with it’s own problems & these problems follow us into our homes.

A couple of examples in Robert Street Marrickvillewhere residents created gardens to protect street trees. To me, they look great & are far better than bitumen up to the trunk.

It is my belief that we need to plant many more trees across Marrickville LGA.  We need larger trees that create shade, both on private property & as street trees. Street trees that grow straight upwards & have a canopy of no more than 2-3 metres are not a ‘shade tree.’  We also need less cement & bitumen, more gardens & pockets of green space outside of formal parks to keep the heat down, for our mental & physical health & for the health of the planet.

Sydney is getting bigger & bigger & with this urban sprawl comes more cement, more hard surfaces & fewer trees.  My fear is that, if climate change does happen in the way the scientific experts predict (& being a prediction, it has a 50% chance of being worse than what they think will occur), that we & our governing authorities will realise just how important trees & green spaces are, but the weather will be too hot & water in short supply that whatever is planted will have trouble surviving.  Bleak I know, but I have read a lot on this subject & none of it is heartening.

So getting back on subject, what Marrickville Council is doing when they are replacing footpaths is terrific & sensible action for the future.  It will allow people to get used to less cement & hopefully encourage them to be actively involved in the garden beds outside their property.

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