Study finds green roofs improve concentration

Study finds green roofs improve concentration:

A new study from Melbourne University has found that environmentally-friendly green roofs are not only good for the environment, they also improve employee concentration.

In the study, published in the Journal of Environmental Psychology, 150 students were asked to press a key as a series of numbers repeatedly flashed in front of them on a computer screen, unless the number was three. Midway through the task half the group was given a 40-second break during which they looked at a flowering meadow green roof and the others looked at a bare concrete roof. The participants who looked at the green roof made fewer errors and had better concentration in the second half of the task.

Dr Kate Lee, Head Researcher, said, “We know that green roofs are great for the environment, but now we can say that they boost attention too. Imagine the impact that has for thousands of employees working in nearby offices. This study showed us that looking at an image of nature for less than a minute was all it took to help people perform better on our task.”

The study deliberately used a 40-second “micro-break” to mirror the mini breaks which happen spontaneously throughout the day. “It’s something that a lot of us do naturally when we’re stressed or mentally fatigued. There’s a reason you look out the window and seek nature, it can help you concentrate on your work and to maintain performance across the workday.

“This study has implications for workplace well-being and adds extra impetus to continue greening our cities. City planners around the world are switching on to these benefits of green roofs and we hope the future of our cities will be a very green one.”

More and more rooftop gardens are appearing in Melbourne and Sydney, including The City of Melbourne offices on Little Collins Street and the M Central apartment building in Pyrmont, Sydney.

image credit . sookie

University of Queensland’s Global Change Institute

University of Queensland’s Global Change Institute building sets new standard for cutting-edge, sustainable building technology


How to Harvest Stormwater in Urban Areas

By Richard J. Magill

One of the more important issues that green infrastructure professionals are discussing these days is responsible and effective ways to harvest stormwater in urban areas. Given the effects of global climate change (temperature increase, rising oceans, extreme weather outbreaks- not the least of which includes devastating drought conditions), we are consequently experiencing profound increases in pollution of drinking water supplies, diminishing recreational-water opportunities, and the widespread degradation of our natural waterways and oceans, among other negative implications. Municipal, state, and federal programs in some parts of the world seem to be responding by promoting legislation that requires urban development projects to include measures to proactively manage and re-use this scarce resource. The proactive approach is particularly apparent in Western Europe, the United States, Canada, Australia, and New Zealand. Other parts of the world are just becoming aware of the possibilities and opportunities associated with wise re-use of this often neglected source of water.

For the purposes of this article, stormwater is defined as runoff collected from roof and ground surfaces, including roadways, driveways, parking lots, plazas, and other impervious areas. Rainwater is defined as runoff from roof surfaces or collection by other devices which don’t allow the rain to come in contact with imperious surfaces which collect pollutants.

The scale of stormwater harvesting and reuse systems can range from small residential systems to very large commercial systems. In the US, outdoor water uses represent 58 percent of the domestic daily water uses, while for hotels and office buildings, outdoor uses represent 10 to 38 percent of the daily water uses, respectively.

harvest stormwater and Re-use in Urban AreasAccording to the U.S. EPA, when harvested rainwater is re-used, it generally is best suited for irrigation and non-potable uses, such as water closets, urinals and air conditioning systems (HVAC), as these uses require a lesser amount of on-site treatment than potable uses. Due to the lower cost of treatment, one of the most common re-use applications of stormwater and rainwater is for irrigation of urban green spaces. Some of the uses include irrigation of athletic fields, golf courses, parks, landscaping, community gardens, and even public water features. The green infrastructure techniques utilized to collect stormwater include bio-swales (rain gardens), enhanced tree pits, and permeable pavements. The following goals are central to the principles of stormwater harvesting and re-use systems:

  • reduction of stormwater pollutant loads and flows to surface waters, helping achieve local stormwater management requirements;
  • reduction in the size of other, more traditional stormwater management practices used to achieve local stormwater control requirements;
  • reduction of the demand on potable water sources; and
  • reduction of stress on the existing water supply and associated delivery infrastructure.

Well-planned, designed, and implemented stormwater harvesting and re-use systems can also be used to obtain valuable Leadership in Energy and Environmental Design (LEED) and other sustainable design credits related to stormwater quantity and quality, and water efficiency. LEED certification is recognized as a cost-effective (especially long-term) and environmentally-responsible practice, and is often embraced by the development community as a necessary initial cost of doing business, in the United States at least.

Top Concerns Related to Harvesting Stormwater and Re-use

Although stormwater harvesting and re-use systems appear are viable alternatives to help achieve required stormwater management standards, as well as reducing the demand on the potable water supply, they are not without significant concerns.

Those concerns include:

  • Potable water supply cross-contamination;
  • Direct human exposure to pathogens;
  • Exposure to pathogens in food crops;
  • Risk of toxic spills (within the stormwater re-use catchment area, and potential for re-use of contaminated water);
  • Concerns with mosquito breeding; and
  • Contaminated pond sediments.
Additionally, there are often not locally well-defined operation and maintenance procedures for rainwater and stormwater harvesting and re-use programs. These operation and maintenance programs help ensure stormwater re-use systems are functioning as designed and are meeting the required water quality standards to protect the public health.

Potential Obstacles Stopping Progressive Stormwater Management Systems

In many areas of the world, rainwater and stormwater harvesting is largely unaddressed by regulations and codes. Many of the requirements that do exist were originally developed for the re-use of reclaimed water (treated wastewater) rather than stormwater. The confusion about the different types of water to be re-used (reclaimed, rainwater, stormwater, etc.) and the lack of legislative guidance for this topic has resulted in differing use and treatment guidelines and standards among federal, state and local governments. Because of the lack of guidance for rainwater and stormwater re-use, these sources of re-used water are often regulated at the same level as reclaimed water, which is typically more clearly defined by past management practices. Although the general guidance for the re-use of rainwater and stormwater is similar to reclaimed and grey-water, it can differ dramatically due to lower levels of initial contamination and the potential end-uses. Often, the treatment requirements ultimately come down to the risk of exposure to pathogens.

The perceived cost of improving stormwater management systems, relative to the actual long-term costs, is also an obstacle that needs to be overcome. The level of treatment required by each locality can influence the number of harvesting and re-use systems that are actually implemented. Simplifying the treatment requirements when public health is not at risk can lower the project cost for those entities intending to install stormwater harvesting and re-use systems and may encourage broader adoption of these improved practices.

What Can Green Infrastructure Professionals Do to Further the Cause?

Stormwater Harvesting and Re-use in Urban Areas

While some governments may resist the codification of more progressive stormwater and re-use practices and regulations, green industry professionals can be leaders in the education and promotion of ideas that advance the stormwater management systems of developed and un-developed countries alike. The most effective means that landscape architects and designers, urban arborists and foresters, structural and civil engineers, and urban and regional planners can use to further the cause is knowledge. If we as professionals continue to pursue innovative, and environmentally and financially responsible practices, and educate citizens, supervisors, and elected officials on these newer management techniques, there can be substantial gains made against the negative effects of inefficient and outdated stormwater management systems in urbanized areas of our planet.

What is Water Sensitive Urban Design(WSUD)?


Strataflow Render water sensitive urban design Citygreen
An Example of WSUD

As urbanization continues to reshape our landscapes, the concept of a Water Sensitive Urban Design (WSUD) has gained prominence as a holistic approach to address the challenges of water management in cities. Let’s look into the intricacies of WSUD, examining its principles, benefits, challenges, and implementation strategies.

Water Sensitive Urban Design (WSUD) is also known as Low Impact Development (LID) in the United States, and Sustainable Urban Drainage Systems (SUDS) in the United Kingdom.

It all refers to the land planning and engineering design approach that integrates the urban water cycle, including stormwater, groundwater, and wastewater management and water supply, into urban design. This is done to minimise the environmental degradation as well as improve the look of the area by creating a circular economy of urban water use.

In urban environments, impermeable surfaces like roads, roofs, driveways, and walkways prevent water from soaking into the ground, resulting in what we call stormwater runoff. Additionally, the presence of vehicles and industrial activities in these areas contributes to the accumulation of pollutants on these surfaces. When it rains, this polluted runoff is funneled through drains, eventually reaching creeks and rivers, causing pollution and degradation to environmentally crucial systems. Water-Sensitive Urban Design (WSUD) is a solution designed to enhance urban areas’ capacity to capture, treat, and recycle stormwater, preventing it from polluting and harming our natural waterways and ensuring rain water is used in the environment in which is falls more efficiently.

Why Use Water Sensitive Urban Design When Designing your Urban Environment?

According to the guidelines released by the South Eastern Councils in Melbourne Victoria, WSUD has been identified as a “means to control flows and filter stormwater to remove pollutants”.

Stormwater is the water that runs off urban surfaces after heavy rainfall. The report said it has been identified as the key cause of pollution and declining health of waterways.

“With increased urban development, the proportion of impervious surfaces in our catchments increases. This increases the velocity and amount of water running into our waterways, creating problems of erosion and flooding and changing natural flow regimes, with associated ecological damage. It also washes more pollutants into our streams, further impacting river health.”

Victoria councils, like other councils in Australia, have recognised the importance of sustainable water management such as WSUD. The release of various guidelines enables organisations to have a first point of reference for their projects.

The design “integrates urban water cycle management with urban planning and design, with the aim of mimicking natural systems to minimise negative impacts on the natural water cycle and receiving waterways and bays”.

Types of WSUD

Stormwater Treatment ElementApplicationLitter/Organic MatterCoarse SedimentFine SedimentTotal Phosphorus/Nitrogen RemovedOil & GreaseReduction in Runoff VolumeConstructionMaintenance
Vegetated SwalesPrimary/SecondaryHHHLLLLL
Bioretention SwalesPrimary/Secondary/Tertiary (may need sediment and litter pre-filtering)HHHMLMLM
Bioretention Basins/RaingardensPrimary/Secondary/Tertiary (may need sediment and litter pre-filtering)HHHMLMLM
Sediment BasinsPrimary, often combined with detentionMHMLLLLM
Ponds/Wet BasinsPrimary/Secondary/TertiaryHHMLLLLM
Constructed WetlandsSecondary/TertiaryHHLMLH
Exfiltration SystemsSecondary (needs sediment and litter pre-filtering)HLMLM
Soil CellsVarious (often combined with filtering and detention)LLLHLHHL

Soft vs Hard Engineering of Landscapes

Soft engineering and hard engineering are two approaches used in water management and urban design.

  • Soft Engineering: In the context of Water Sensitive Urban Design (WSUD), soft engineering refers to the use of natural or nature-based solutions to manage water, such as vegetation, soil, and natural drainage systems. Soft engineering aims to mimic natural processes and ecosystems to reduce runoff, improve water quality, and enhance the aesthetic and ecological value of the landscape. Examples of soft engineering in WSUD include bioretention swales, vegetated basins, soil cell tree pits, and constructed wetlands.
  • Hard Engineering: Hard engineering, on the other hand, involves the use of man-made or engineered structures to manage water, such as pipes, concrete channels, and traditional drainage systems. In the context of WSUD, hard engineering components may be necessary in situations where factors such as the need to transport water across paved areas, land availability, or topography require the use of piped or hard components. Examples of hard engineering in WSUD include piped drainage systems, concrete structures, and permeable hard surfaces such as rock rip-rap or paving.

WSUD elements are most effective when vegetation and trees are used in their design, factors such as the need for water to be transported across paved areas, land availability, and topography may require the incorporation of hard components into a broader WSUD system.

While there is no standard approach that should be applied to all situations, and a hybrid solution that combines both soft and hard engineering components may be necessary to address site-specific opportunities and constraints, Creating softscapes with increased greenery and trees will be a great economic, environmental and health impact to the local community.

Case Study

In places such as Canada, capturing stormwater is a mandatory requirement for all new constructions, as a means to effectively manage water and prevent a higher level of pollutants from entering municipalities.

In flat open areas such as carpark where pollutants and stormwater runoff can be a concern Citygreen’s Stratavault offers a cohesive solution that connects stormwater management with landscape tree design. Instead of stormwater immediately entering the city infrastructure and depleting the valuable water resource by taking it out of area, our integrated water sensitive urban design directs the stormwater into the Stratavault matrix.

This innovative system allows trees and soil to utilize the water for their own needs and growth while effectively cleaning the excess water of contaminants before the water enters the pit’s base chamber. Additionally, this design enables the recycling of water for on-site irrigation & a slower release back into the city’s infrastructure during periods of lower demand

Eaton Mall jpg water sensitive urban design Citygreen

What are the Key Principles of WSUD?

Some of the key principles of WSUD as stated in the Urban Stormwater: Best Practice Environmental Management Guidelines (BPEMG) include:

  • Protect and enhance natural water systems within urban environments.
  • Integrate stormwater treatment into the landscape, maximizing the visual and recreational amenity of developments.
  • Improve the quality of water draining from urban developments into receiving catchment environments.
  • Reduce runoff and peak flows from urban developments by increasing local detention times and minimising impervious areas.
  • Minimise drainage infrastructure costs of development due to reduced runoff and peak flows.

What are the Benefits of WSUD?

The top benefits of using water sensitive urban design include:

  1. Flood Mitigation: By reducing stormwater runoff and increasing water infiltration, WSUD minimizes the risk of flooding during heavy rain events.
  2. Improved Water Quality: Natural filtration methods used in WSUD systems effectively remove pollutants, enhancing the quality of water entering streams and rivers.
  3. Urban Cooling: Urban green spaces and water features provide cooling effects, mitigating the urban heat island effect and improving overall urban livability.
  4. Biodiversity Enhancement: WSUD encourages the creation of habitats for various species, contributing to urban biodiversity and ecosystem health.
  5. Enhanced Tree Growth: By directing extra resources to nearby trees you give the tree more opportunity to successfully grow
  6. Increased Social Outcomes: Improving the greenery, liveability, and functionality of shared urban spaces increases the the physical, social and mental health of the community.

What are the Challenges of WSUD?

Given that water-sensitive urban design is a relatively new concept within the realm of urban landscaping, there emerge several challenges in the process of designing new WSUD spaces. These include:

  1. Regulatory Barriers: Traditional regulations and codes may not be aligned with WSUD principles. Overcoming regulatory hurdles and advocating for changes to local ordinances can be a significant challenge.
  2. Lack of Awareness: Many stakeholders, including local governments, developers, and the general public, may be unaware of the benefits and importance of WSUD.
  3. Funding Constraints: WSUD projects may require upfront investments for designing, construction, and maintenance. Convincing stakeholders to allocate budgets for these projects in the face of other competing priorities can be challenging.
  4. Infrastructure Retrofitting: Integrating WSUD into existing urban areas often requires retrofitting existing infrastructure. This can be complex, costly, and disruptive to ongoing operations.
  5. Maintenance and Long-Term Management: Proper maintenance of WSUD components is essential to their effectiveness. Ensuring consistent and appropriate maintenance practices can be challenging, especially if communities lack the necessary resources or knowledge.
  6. Data Availability: Designing WSUD systems requires accurate and up-to-date data on rainfall patterns, land use, and hydrology. In some cases, obtaining this data may be a challenge, especially in areas with limited resources for data collection.
  7. Interdisciplinary Collaboration: WSUD projects require collaboration among various disciplines, such as urban planning, landscape architecture, civil engineering, and environmental science. Coordinating and aligning efforts across these disciplines can be complex.
  8. Resilience to Climate Change: WSUD systems must be designed to accommodate changing climate patterns, including more frequent and intense rainfall events. Ensuring the resilience of these systems can be a challenge.
example of tree pits integrating water sensitive urban design

Citygreen® products are designed to ensure it supports the effort for a sustainable water management. The Stratavault’s™ modules leave over 94 percent of its total volume for root growth and storm water harvesting. Find out more about the products here.

Load More...

“Great customer service, quick response times and a very in depth QA system with constant support.”

- Laura Wiesenekker, Project Engineer, Densford Civil -

“Citygreen is a very professional  business, and I found everything was great in terms of deliveries, product supply and information. It was all forthcoming and helped us to complete the project.”

- Keith Burns, Architect/Designer, Keith Burns Architect -

“Citygreen offered training and invaluable technical assistance during the works.”

- James Callan, Estimating Manager, Complex Co Pty Ltd -

“Our experience, in working with a Citygreen Design Studio was second to none. We found responses from the design studio to be very timely, and technically thorough. We went backwards and forwards a number of times, looking at different iterations of the design and, nothing was too much trouble to examine and explore different possibilities. I would highly recommend the Citygreen Design Studio to any future client considering using your services.”

- Sandra Smith, Principal Landscape Architect, City Of Monash -

“We are big on compliance on all projects, and the fact that their SmartCertify cloud platform covers all bases, and supports their 20 year warranties, is critical – especially that these pits are being installed under roadways and footpaths.”

- Johny Purkaystha, Civil Program Engineer, Central Coast Council -

"I reviewed all the previous projects that we have installed in the past couple years using your product and I can happily report back that we have 0% mortality in the soil cells, which is incredible!"

- Brendan Wilton, CEO, Trim Landscaping, Bedford, Canada -