“If we care about the quality of our drinking water, and the health of our local waterways, we need to rethink the way we deal with stormwater”
That was the take-home message for around 30 residents, business owners, students and Birriban Landcare members who attended a recent workshop run by Council at Katoomba High School.
The workshop highlighted the damage done by urban stormwater runoff – the biggest single threat to local waterways. It also showed practical things people can do on their own properties to protect local creeks.
Council’s Aquatic Systems Officer, Amy StLawrence said, ”In nature, 90% of rainwater soaks into the ground, feeding plants and recharging all-important ground water systems.”
“But in urban areas, hard surfaces such as roads, roofs and paving fundamentally change the way rainwater moves in the landscape.”
“When it rains, water that falls onto these areas is channelled into downpipes and drains. It’s then discharged in one hit, unfiltered and at speed, directly into our waterways.” This causes enormous problems for local creeks, lakes and lagoons.
Stormwater tears away and destroys creek banks. Soil and sediment from unsealed driveways, roads and building sites clog creeks and waterholes. Decaying organic matter, such as grass clippings, suck oxygen out of the water, making it difficult for aquatic life. The extra nutrients then help weeds to flourish. Stormwater also flushes pollutants, such as chemicals, sewage and litter, directly into creeks.
“Many of our local creeks are showing signs of stormwater stress, while once popular swimming spots are no longer suitable for swimming.”
“The challenge is to capture and reuse stormwater as a resource, or to slow it down and filter it before it enters our waterways.”
“The best way to do this at home is to install a rainwater tank or a raingarden,” said Ms St Lawrence.
A raingarden looks like an ordinary garden bed, but uses a special soil mix and specially selected plants to retain, hold and filter stormwater. Raingarden beds are easy to build using readily available materials. And they generally don’t need watering, so they are easy to care for.
Even if rainwater tanks and gardens are not an option, Council says you can still do your bit for local waterways by keeping leaves, detergents, chemicals and sediment out of gutters and drains, and by washing your car on the lawn instead of the driveway.
“One of my favourite things about living in the Mountains is having beautiful creeks and bushland on my doorstep. I knew my local creek had problems, but I had no idea how much damage stormwater causes. I can’t wait to get started now on my own raingarden,” said John Smith, from Leura, who attended the workshop.
“My business is adjacent to Leura Creek, and I’m concerned about the stormwater runoff from my carpark. I want to put in a raingarden to slow down and filter the water before it goes into the creek,” said a Mary Smith, a local business owner.
The workshop was run as part of a $300,000, twelve-month project by Council (funded by Council’s Environment Levy) to improve the health of Leura Falls Creek and downstream Leura Cascades – in partnership with Water NSW.
As part of the project, Council is also restoring sections of the creek and installing treatment systems at stormwater outlets across the catchment.
Leura Cascades is one of the Blue Mountains most iconic tourism destinations. Like many local waterways, it also flows into Warragamba Dam, which services over four million people with drinking water.
Local volunteers, supported by Council and Water NSW, will be conducting regular water quality testing in the catchment to track the results of the project.
A similar project at Glenbrook Lagoon – also funded by Council’s Environment Levy – aimed at reducing stormwater pollution, is showing early signs of success. Tests show the new, $120,000 stormwater filtration systems there are reducing bacteria entering the lagoon by up to 90%.
Council’s Environment Levy raises around $1.5 million annually from Council rates and is used to restore local creeks, improve water quality, control noxious weeds and maintain walking tracks. It also funds regular water quality monitoring at over 40 local creek sites. Council is currently restoring over 130 creek and bushland sites across the City.
Council is running a Catchment Crawl Tour of the Leura Falls Creek Catchment on 3 May for local residents and business owners. Places are limited. To book, or for more information, call Council on 4780 5000.
Want to see a working rain garden in action? Visit the Blue Mountains Cultural Centre. There’s a rooftop raingarden on the viewing platform. To find out how to build your own rain garden, visit