Riverside Crescent Subcatchment Management Plan 2010

Birds on Fatima Island in the Cooks River

I downloaded the report because there was interest in the issue. The first thing that struck me was the cover page. It is a photo of the banks of the Cooks River probably taken early last century, but that’s just a guess.  The environment looks unbelievably bad, not what I expected at all. I had a vision of a pristine river with natural banks & trees everywhere. Instead there is a very large denuded area about the size of Steele Park with 4 tall trees, 1 dead & another on its way out.  There are around 16 newly planted saplings in the photograph with what appears to be a team of men doing some work chopping away sandstone from an area about 20 metres from the bank. The bank itself is ‘natural’ with not a mangrove to be seen. Pity copyright prevents me from including the photo.

This photo shows that Marrickville Council have done enormous restoration & re-vegetation work on the Cooks River, its bank & the public space alongside the riverbank which I guess was precisely what they intended.

On to the report itself – First up is an aspiration of what the future could be like (words in bold are my emphasis) –

“In 2050….. Our people-friendly streets & roads are clean & there are minimal hard surfaces. Streetscapes, roads & roofs are ecosystems, available for local food production. Stormwater treatment systems are also habitat for frogs, insects and bandicoots. Transport is now completely green, there are few cars & people mostly walk & cycle.  Our community revolves around shared green spaces that are self-sufficient with water. Parks have wetlands & forest reservations. We swim in Dibble Avenue Waterhole & the Cooks River waterways that are also habitat for wildlife. The Cooks River & its foreshores are clean, in a natural state & can be used for recreation & fishing.”

Now wouldn’t that be amazing & something wonderful to pass on to future generations.

Marrickville Council has so far created 3 Subcatchment Management Plans: Illawarra Road Subcatchment Marrickville South, Tennyson Street Subcatchment Dulwich Hill & now Riverside Crescent Subcatchment in Marrickville South.  There are 21 subcatchment areas in Marrickville LGA, so it’s big job.

I found the Riverside Crescent Subcatchment Management Plan exciting for a number of reasons.

• The goals are big, but achievable.
• Council intends to work with the community.
• Private property issues with stormwater & the creation of permeable surfaces are also to be addressed.
• Council expects measurable improvement by 2019.

Cooks River

Approximately 60% of the Riverside Catchment is impervious surface. Of that 60%, roads make up 34% with roofs, driveways & carparks making up the remaining 66%.

From the Report – “The implemention of the Riverside Crescent Subcatchment Management Plan can only happen if citizens make practical changes on their properties. (my emphasis)

The idea of “depaving” is gathering momentum in the USA, especially in Portland, Chicago & Berkeley. With the permission of a landowner, paved areas are removed & replaced with vegetated areas. In Portland, a community organisation called Depave.org has led depaving projects in private backyards, school yards & parking lots.” (Portland has done some incredibly innovative & dynamic things regarding street trees, verges, kerbs & the community is heavily involved. I would love to visit & see for myself.)

As with ‘green laneways,’ the only way to stop up to 85% of rainwater becoming stormwater & ending up in our drains & then eventually into the small creeks in the LGA, the Cooks River or the ocean is by removing as many of the impermeable surfaces as we can. Making surfaces permeable

A section of fantastic restoration work on the bank of the Cooks River at Ewen Park

allows water to go where it should, into the ground or into rainwater storage tanks for use in & around the home. Once rainwater enters the ground, it fills the groundwater & travels through the natural causeways through the ground to reach creeks, the ocean or the Cooks River. The water is by then, cleaned of pollutants. Council isn’t kidding when they say they are going to need to co-operation of the community.

Last week the Australian New Zealand Climate Forum released figures showing that Sydney is already 0.65C hotter than Newcastle. This may not seem like much, but a global temperature rise of just 2 degrees is thought to be catastrophic & result in major problems with food production, water, rising sea levels, 30% animal & plant extinction, weather patterns, floods, drought, & unsustainable living conditions for people.

The heat island effect is causing the heat stored in our many hard surfaces to remain during the night & this makes for one very hot Sydney.  We have already noticed significant changes over the last 3-4 years & unless we do something about this soon, Sydney is only going to get hotter.

Stamped cement driveways will be a thing of the past because we will eventually choose to not live with the heat stored on our property.  Hopefully Council’s Subcatchment Plan will enthuse people to remove theirs & install a permeable driveway instead. If Marrickville Council are successful in encouraging community co-operation & participation, there will be huge changes in the way the community views the environment in terms of water, trees, verges, litter & dumping.

Dibble Avenue Waterhole - this has the potential to be amazing

Dibble Avenue Waterhole is also targeted in the Plan. According to Council’s Report, the historic & potentially very beautiful Waterhole that is fed from direct rainfall, groundwater & stormwater runoff from adjacent properties has “high concentrations of heavy metals including arsenic, cadmium, copper, mercury, nickel, lead & zinc. These exceed guidelines’ values & pose an ecological risk.   ….up to 25 species of birds including several important migratory & wetland birds, such as the Eastern Curlew. Chestnut Teals, Dusky Moorhens & Australian White Ibis, have been observed most recently. Long finned eels, dwarf flathead gudgeon & mosquito fish have also been recorded.”

I am really happy that Council is doing this kind of work, because not only will it improve our environment in terms of general cleanliness & a cleaner river that we may one day be able to swim in, it will also increase biodiversity by offering homes & food for urban wildlife.  It will also be tackling global warming & the lessening the impact of climate change.  Okay, it’s a small scale, but hopefully all the Councils in Sydney & across Australia will do the same or similar & this process is repeated across the world.  We have to clean up our own back yard.

One very small thing we can do right now is stop buying bottled water or stop throwing plastic bottles away as litter. In all my walks along the Cooks River, the most common litter I see in the river, along the banks & in stormwater catchment drains are plastic water bottles. Some of them can travel to the Cooks River through the stormwater drains from as far as Newtown. Just making a change here will lessen the pollution load in the Cooks River.  It’s Marrickvlle LGA’s little piece of paradise & it can be so much better.

There is much more in the Riverside Crescent Subcatchment Management Plan. For those of you who are interested, it can be downloaded here (6.5MB) – http://www.marrickville.nsw.gov.au/edrawer/Files/331251926/TRIM_TR_REC_1207345.PDF

Cooks River with Tempe railway bridge & the bridge at the Princes Highway in the distance

 

 

Green laneways & stormwater

Taken from the barrier around Council works in Steele Park Marrickville South

Around 85% of rainwater that falls on a typical large city will flow into stormwater drains. Our stormwater drains in Marrickville LGA are around 100 years old &, in many areas, totally incapable of managing heavy or prolonged rain. Now that more people will be moving into the area, our ancient drains are going to become a significant problem. Replacing them is a costly nightmare.

Usual type of road flooding in the Inner West

By their nature cities cause stormwater problems because the majority of the surfaces are covered by concrete or bitumen.  You only need to drive around Marrickville LGA when it is raining to see that the stormwater drains cannot cope when it rains.  Substantial volume of water builds up along gutters.  In a heavy downpour many of the streets of the Inner West become dangerously flooded. Half a road can be 30 cms deep in water.  While in the short-term this is great for any nearby street trees, it is not so great for infrastructure, the Cooks River or the safety of drivers.

Many cities worldwide have the problem of old & inadequate stormwater drains. Some of them are tackling the problem in a simple but creative way by replacing bitumen & cement with permeable surfaces. The US city of Chicago has started a Green Alley Program. Mind you, environmental programs that address global warming & create a sustainable, more livable city, are fast making Chicago the ‘greenest’ city in the world.

New permeable paths recently created by Marrickville Council in Steele Park Marrickville South

Chicago’s Green Alley Program established in 2007 is laying permeable surfaces in their 3,058 km (1,900 miles) of alleyways. All up this amounts to 14,163,997 sq metres (3,500 acres) of impermeable concrete in 13,000 alleys. These figures make it much easier for me to imagine the positive impact.

Another issue for Chicago was untreated stormwater flowing into Lake Michigan, affecting water quality.

Permeable surfaces prevent around 80% of water from rushing into stormwater drains by allowing most of the rainfall to flow naturally into the ground. This is important for many reasons, including topping up the groundwater table.

Impermeable surfaces are replaced with crushed rocks, recycled slag or recycled crushed concrete, or, with pavers designed to channel water into the ground. Alleys are still suitable for use by all sorts of vehicles, including bikes & by pedestrians. They won’t become muddy or trap cars in boggy ground.

Additionally, the products that make permeable surfaces in the green alleys are light in colour (high albedo) with light reflecting qualities. They reflect rather than absorb sunlight, significantly lessening the Heat Island Effect.  They also make dark areas brighter at night, as they reflect moonlight & potentiate any street lighting.

Permeable path in Sydney Park

What I find really exciting about Chicago’s Green Alley Program is that they see green alleys as an improvement to people’s quality-of-life.  They work with the cooperation of residents to encourage use of alleys  as an extension of living space where appropriate. Obviously some alleys are frequented by traffic, but others are a rarely frequented space used mainly for the placement of garbage bins. We have the same situation in Marrickville LGA as well as the old ‘dunny runs.’

Chicago encourages planting small bird-friendly native gardens along the edges of alleys & also encourages planting shade trees at the back of people’s property to create shade in the alley. Where it’s appropriate they install rain gardens to capture roof water from a downward pipe that would usually channel rainwater collected from the roof onto the road surface. They also install water tanks & bio-swales where appropriate.

Most alleys have community compost bins for everyone to use.

Expensive? Well yes & no. Obviously staff time is expensive, but there are many ways to start employment programs where the costs are kept down whist giving people a chance to learn a skill. Rainwater tanks are expensive, but this could change.  I imagine bio-swales are expensive to create, however a small rain garden isn’t & the plants could be grown at the community nursery.  Good topsoil around the edges of alleys to encourage residents to plant the area & care for it isn’t too expensive either.

Permeable surfaces in Chicago alleys were costed at around US$45/sq yard.  This has got to be comparable with laying impermeable surfaces.

Chicago alleys have become places where people sit in the sun (or shade) & talk with their neighbours. The alleys stop being places where potential thieves walk to case entry points. Beauty comes into what are often ugly & neglected areas full of rubbish.

Back lanes are often cool places because the wind travels freely unhampered by tall walls. Imagine if they were a nice place to sit, an extension of your back garden.  It’s what they do in many places overseas & have done for hundreds of years. Often new arrivals to Australia find it strange that everyone either sits inside or in their private back garden. They are used to sitting on the porch or near the street so they can say hello to everyone & greet passersby.  Laneways can become places like this. There is no reason why the end or the edges can’t become a community garden. This will offer urban wildlife more sources of food if any planting includes natives.

A typical laneway complete with dumped rubbish

I think we get conditioned to accept the status quo. We view laneways as utility places even when the utility has stopped decades ago. We periodically clean them & store garbage bins there, except in those lanes where this has been prohibited.  Graffiti artists have recognized the need for laneways to be spruced up, though their method may not be everyone’s cup of tea.

2010 recorded the hottest temperature world-wide since they started recording temperature. All the experts believe the heat will get worse which means the Heat Island Effect will get worse.  We will find we are roasting in the oven we created.  I think a time will come when people will willingly rip up the stamped concrete that surrounds their house because power costs to cool our homes will be very expensive & we will be forced to embrace new ways of living.  Actually, they are the old ways of living before King Concrete began its reign.