Landscaping to Reduce Stormwater Damage
We are learning better ways to manage the stormwater run-off from built areas by exploring strategies from other cultures and by observing existing natural systems.
Landscaping to reduce stormwater runoff and damage from extreme wet weather events can include a combination of hard and soft engineering, and vegetation.
Stabilising a Stormwater Channel after Fire
How and why Blue Mountains City Council acted quickly to stabilise the stormwater channel at the end of Connaught St Blackheath after the 2019 bushfires.
Future-Proofing with Water in a Japanese Inspired Garden
Inspired by Japanese Zen Buddhism, Anne Mellor has designed her Springwood home around water. Facing the challenges of living in a Flame Zone, while also dealing with stormwater impacts on a sloping block, she shares how her water management strategies, including Japanese gutters and a dry creek bed, are reducing her risk of fire, flood and heatwave, while also creating a sanctuary of peace and tranquillity.
The Bush Doctor Protecting Our Swamps
Springwood resident Shane Grundy is The Bush Doctor. He uses soft engineering techniques to help rejuvenate swamps and improve water quality in the Blue Mountains. His own garden is aesthetically beautiful, but also manages the stormwater from two adjacent houses. Rainwater hits the hard surfaces such as the rooves and driveways. Some of it is stored in a water tank. The rest is directed into the landscaped garden. Sandstone-lined courses and rock basins slow the stormwater flow, giving it a chance to infiltrate into the ground. This process is something that Shane and his team construct on a much larger scale across the Blue Mountains to protect the swamps which act like giant sponges sitting on our sandstone. They manage peak flows and support perennial creeks and streams.
Soft engineering employs tough but biodegradable materials such as coir logs and straw bales. It’s used to address erosion often caused by stormwater runoff. It does this by slowing the velocity of water and distributing its volume across larger areas.
Taking inspiration from Southeast Asian rice paddies
Southeast Asian rice paddies are one of the inspirations behind a stormwater treatment initiative at Glenbrook, designed to protect Knapsack Creek and ultimately, the Hawkesbury Nepean River.
Rain gardens and naturalised stormwater channels slow and clean stormwater, reducing the nutrients and sediments carried into waterways. Left unchecked, these nutrients promote algal blooms and weed growth. Excessive loads of sediments change the natural flow of streams.
These ‘nature-based’ treatment systems are also examples of ‘water banking’ which focuses on storing water in the landscape. This supports biodiversity and creates a cooler environment. It also recharges groundwater, preventing surface flows from running quickly through the system and causing erosion.
Glenbrook Rain Gardens: A Simple & Natural Solution for Water Protection & Flood Prevention
Blue Mountains City Council has taken the initiative by creating rain gardens in many catchments to better protect waterways, manage water sustainably and demonstrate how these solutions can be incorporated at different scales, including home gardens.
Most recently Council teams and contractors collaborated with Sydney Water to create three different types of native rain gardens at Glenbrook Visitor Information Centre, showcasing how sustainability and beauty are the natural features of these innovative but simple water management solutions.
Water Management to Reduce Disaster Risk
Andy redesigned the driveway above his house to direct excess stormwater away from his home to avoid flooding. He then cleaned and collected this water in a 20,000l tank to be used by the RFS for firefighting.
Surplus was used for irrigation. Grey water was cleaned by an accredited grey water treatment system, and distributed through the garden with sub-surface drip irrigation. Black water was treated by a digestive ecomax which released the cleaned water into an evaporation trench. Together, all these systems helped create the moist soil sponge that could support life even in the longest drought.
The Exquisite Sights and Sounds of a Recovering Swamp
In the early 2000s North Lawson Park was used as an off roading circuit for 4WDs and trail bikes.
When John and Jeanine of Lawson witnessed the rapid destruction of the environment they loved due to vehicle encroachment, they felt desperately saddened. And enraged. They witnessed the delicate soils of an ancient swamp churned up in 30 minutes.
Community and agency support grew into a collaboration as a result of the public meeting and growing awareness that North Lawson Park was a habitat for the endangered Giant Dragonfly and the vulnerable Persoonia acerosa (needle geebung), as well as potential habitat for the Blue Mountains Water Skink.
Once the damaging activity reduced, talks with Blue Mountains City Council about regenerating the swamp began. Water flow had significantly altered and erosion was creating sedimentation problems in the reeds. “The racetrack had cut off moisture from going into the middle of the swamp,” said Greater Sydney Landcare’s Xuela Sledge, who worked with National Parks and Wildlife Services at the time and was an advocate for the restoration campaign. There was a chance the swamp would dry out. “Those swamps take a long time to get to that point,” said John. “We were concerned that it wouldn’t recover. And it’s still not fully recovered. It takes about 50 years we’ve been told.”
In a final-push collaborative effort, local residents, Blue Mountains City Council staff, National Parks and Wildlife Services and the then federally funded program Green Corps all came together on January 30 2002 to repair the swamp. They levelled out potholes and mounds created by the bikes, then installed long coils of coconut fibre, coir matting and sandbags to realign the water flow back into the swamp. They relocated some of the sedges in order to prompt revegetation of damaged areas.
It’s been just over twenty years since then. Today, the track to the swamp is narrowed by encroaching vegetation and has become the home of busy ants and Drosera plants. It peters out completely down among the sedges where you can still find the decomposing remains of coconut fibre coils.