70% A revitalised city centre at the heart of a A revitalised - - PowerPoint PPT Presentation

WSUD - Raingardens with Infrastructure Upgrades IPWEA NSW 2014 Works Conference May 2014

Iraj Shrestha Graduate Project Engineer

City Infrastructure & Traffic Operations

City Operations Division City of Sydney

• City Of Sydney

26 km2

25% of NSW GDP 8% of National GDP 200,000 businesses 390,000 workers 1M visitors a day 4M tourists a year

We have committed to reducing emissions by

70%

The Sustainable Sydney 2030 vision for a world- leading metropolis requires the City to respond to the changes that are occurring through its growth. The overarching themes for Sydney 2030 are:

• An integrated inner Sydney transport

network

• A liveable green network
• Activity hubs as the focus for the City’s

village communities and transport

• Transformative development and

sustainable renewal

• A revitalised city centre at the heart of a

global Sydney “By 2030, the City will reduce greenhouse gas emissions by 50% compared to 1990 levels, and by 70% compared to 1990 levels by 2050.”

Sydney 2030 Vision

Th Th le le th th Th Th Th “By 2030 the City will reduce greenhouse gas “By 2030, the City will reduce greenhouse gas emissions by 50% compared to 1990 levels and i i 0% d 1990 l d missions by 50% compared to 1990 levels, and and by 70% compared to 1990 levels by 2050 b 0% d 1990 b 20 0.” he Sustainable Sydney 2030 vision for a world he Sustainable Sydney 2030 vision for a world- ading metropolis requires the City to respond to di li i h Ci d ading metropolis requires the City to respond to he changes that are occurring through its growth. h h i h h i h he changes that are occurring through its growth

• wt

he overarching themes for Sydney 2030 are h hi h f S d 2030 e: h

• An integrated inner Sydney transport

An integra egra network network

• A liveable green network

A liveable green network

• Activity hubs as the focus for the City’s

Activity hubs as the focus for the Cit e Ci village communities and transport village communities and transport

• Transformative development and

Transformative develo velo sustainable renewal sustainable renewa al

• A revitalised city centre at the heart of a

A revitalised city city global Sydney

3

• Sydney’s 2030 Vision

We will also reduce sediments and suspended solids by 50% and nutrients by 15% which are discharged into the waterways

The Sustainable Sydney 2030 vision for a world- leading metropolis requires the City to respond to the changes that are occurring through its growth. The overarching themes for Sydney 2030 are:

• An integrated inner Sydney transport

network

• A liveable green network
• Activity hubs as the focus for the City’s

village communities and transport

• Transformative development and

sustainable renewal

• A revitalised city centre at the heart of a

global Sydney “By 2030, the City will reduce the whole City’s mains water consumption by 10% of 2006 levels..”

Raingarden Deployment

• Since 2008 the City has constructed 106 raingardens
• Covering over 2300 m2
• Multiple benefits such as water quality improvement,

increased greenery, traffic calming and increased amenity

TYPICAL RAINGARDEN DESIGN

Raingardens – Lining Materials

Polypropylene Shotcrete

Raingarden Size & Depth

Limitations

• Limited locations in highly urbanised areas
• Competing priorities such as removing parking or

encroaching on to footway

• Generally located in kerb extensions in no stopping zones

Raingarden Size & Depth

General Dimensions

• Ideal water ponding depth 150 – 200 mm
• Maximum ponding depth 300 mm
• Minimum size 6 m2, Average size 20 m2

Raingardens – Poor Outcomes

• Small, narrow and shallow raingardens are

prone to problems

Raingardens – Impacts of Trees

• Incorporating existing trees into unlined systems
• Damage to tree during construction
• Damage to liner
• Shading effects
• Leaf litter

Raingardens – Selecting the Type

• Knowledge of the soil & ground water characteristics of

the local environment

• Unlined where practical

Raingardens – Layer Tolerances

• Attention to detail
• Layer thickness control
• Educating staff and contractors
• Use experienced consultants to build knowledge and skills
• Do not overfill

Raingardens – Water Entry Points

• Erosion control
• Silt and debris build up at entrance
• Multiple dissipation arrangements trialled
• Drop water in to raingarden

Raingardens – Water Entry Points

• Stop silt and debris entering vegetated area
• New entry pit designed and trialled
• Reduced maintenance
• Improved visual appearance

Raingardens – Plant Selection

• Highly visible in urban environment
• Use larger plants and dense planting
• Instant green impact
• Cost effective

• Adjust planting scheme to suit community expectations
• Structured or unstructured

Raingardens – Plant Selection

Raingardens – Recycled Materials

• Recycled glass in transition layer and pipe backfill
• Green Star concrete in construction works

Raingardens – Performance Monitoring