Page 1

Urban Ecology _ LIUDD Case Study

Brendan Clemens


Contents: Karaka _ Introduction

1

Karaka _ Quantification

2-6

Karaka _ Stormwater Devices

7-9

Karaka _ Conclusion

10


Karaka _ Introduction What if we could design cities to cleanse urban waterways and increase New Zealand’s biodiversity? Low Impact Urban Design and Development (LIUDD) is an approach which works with nature, using design features such as rain gardens and storm water treatment as well as green roofs to reduce pollutants entering urban streams and harbours, while at the same time creating green spaces for New Zealand plants and animals to live in and green spaces for people to enjoy. LIUDD stands for Low Impact Urban Design and Development. LIUDD is about minimising and avoiding impervious surfaces in which water cannot pass though such as concrete, as well as the use of vegetation to help stop sediments and pollutants. This also includes minimizing energy, material use and waste created in an urban environment. LIUDD is about learning how natural systems can regulate the water flows and surface temperature so that through designing-in natural features we are able to create cities that can reduce flooding, filter pollutants and keep buildings cooler in summer without expensive air conditioning or heating during winter.. As the climate changes, with more heat waves and heavy rain events predicted in many parts of New Zealand, cities will need to adapt and LIUDD is a sustainable way to help achieve this.


Karaka _ Quantification Buildings: Commercial/ Residential (Left side) 15m

10m 20m

20m

x56 = 11,200 m sq.

=300 m sq.

=200 m sq. 20m 20m

x170 = 51,000 m sq.

Total amount of buildings: 138,280 m sq.

x18 = 28,800 m sq.

(At least half of all buildings will be green roofs, with the other half being PV Panels.) Green Roof: 70,340 m sq. PV Panels: 67,940 m sq.

=1600 m sq.

Residential (Right side) 12m

8m 15m

x20 = 2,400 m sq.

=120 m sq.

Court Yards & Open Space:

20m

x187 = 44,880 m sq.

=240 m sq.

Total amount of Court Yards & Open Space: 91,000 m sq. All courtyards and open space are public spaces and shared by everyone.


Karaka _ Quantification Lane:

Roads: Main Road: 865m

187m

137m

24m

4m

4m

=5,899 m sq.

=65,175 m sq.

=8.051 m sq.

Street:

Road: 401m =25,898 m sq.

6m

784m

480m

326m

6m

6m

=21,054 m sq.

=31,000 m sq.

6m

=50,633 m sq.

Total amount of roading: 207,710m sq.

Footpaths: 865m

401m

=37,243 m sq. X2 = 74,486 m sq.

326m

2m

4m

480m 2m

=7,018 m sq. X2 = 14,036 m sq.

Total amount of Footpaths: 160,210 m sq.

=8,633 m sq. X2 = 17,266 m sq.

2m =10,333 m sq. X2 = 20,666 m sq.

784m

2m

=16,878 m sq. X2 = 33,756 m sq.


Karaka _ Quantification Rain Ponds & Stormwater Ponds : Pond 2:

Pond 1:

=4,800 m sq.

=3,200 m sq.

Pond 3:

Pond 4:

=12,800 m sq.

=8,000 m sq.

Total amount of Rain Ponds & Stormwater Ponds: 28,800 m sq.

Swales & Rain Gardens: (on roads) 865m

1.25m

2m

=1,081.25 m sq. X2 = 2.162.5 m sq.

=1,730 m sq.

326m

401m

865m

480m 1.25m

=407.5 m sq. X2 = 815 m sq.

1.25m =600 m sq. X2 = 1,200 m sq.

1.25m

=501.25 m sq. X2 = 1,002.5 m sq.

Total amount of Swales & Rain Gardens: 8,870m sq. 784m

1.25m

=980 m sq. X2 = 1,960 m sq.


Karaka _ Quantification Buildings: 138,280 m sq. Court Yards & Open Space Paved: 91,000 m sq, Roads: 207,710 m sq. Footpaths: 160,210 m sq. Rain Ponds & Stormwater: 28,800 m sq. Swales & Rain Gardens: 8,870 m sq. Open Space & Re Vegetation: 744,400 m sq. Permeable Surfaces: Rain Ponds & Stormwater Swales & Rain Gardens Open Space & Re Vegetation

Total: 782,070 m sq.

Permeable paving is a range of sustainable materials and techniques for permeable pavements with a base and subbase that allow the movement of stormwater through the surface. In addition to reducing runoff, this effectively traps suspended solids and filters pollutants from the water

Impervious Surfaces: Buildings Roads Footpaths Court Yards & Open Space Paved

Total: 597,200 m sq.

Impervious surfaces are mainly artificial structures—such as pavements (roads, sidewalks, driveways and parking lots) that are covered by impenetrable materials such as asphalt, concrete, brick, and stone as well as rooftops. Soils compacted by urban development are also highly impervious.


Karaka _ Quantification Permeable Surfaces: Rain Ponds & Stormwater Swales & Rain Gardens Open Space & Re Vegetation

Total: 782,070 m sq.

Impervious Surfaces: Buildings Roads Footpaths Court Yards & Open Space Paved

Total: 597,200 m sq.

Peak Discharge: Q= 0.00278 x C x I x A Permeable Surfaces: Q= 0.00278 x 0.98 x 70 x 59 = 11.25 m3 sec

Q = Peak Discharge (m3/s) C = Run Off Coefficient – impervious: 0.98 urban lawns: 039 I = Rainfall Intensity (mm/hr) – 70mm per/h A = Catchment Area (ha)

Impervious Surfaces: Q= 0.00278 x 0.39 x 70 x 78 = 5.92 m3 sec Estimated Volume of Storage for 2year Rainfall: V estimated= 1.5 x (Q post) x D V estimated = required storage volume (m3) Q post = post development peak discharge (m3/s) D = duration of storm (sec)

V estimated= 1.5 x (11.25 + 5.92) x 3600 = 92,718 m3


Karaka _ Stormwater Devices Permeable & Porous Paving Master Plan

Permeable paving is a range of sustainable materials and techniques for permeable pavements with a base and subbase that allow the movement of stormwater through the surface. In addition to reducing runoff, this effectively traps suspended solids and filters pollutants from the water. Although some porous paving materials appear nearly indistinguishable from nonporous materials, their environmental effects are qualitatively different. Whether pervious concrete, porous asphalt, paving stones or concrete or plastic-based pavers, all these pervious materials allow stormwater to percolate and infiltrate the surface areas, traditionally impervious to the soil below. The goal is to control stormwater at the source, reduce runoff and improve water quality by filtering pollutants in the substrata layers. The permeable paving will be used to help with stormwater control and environmental factors. All footpaths and courtyards will be built using this kind of product.


Karaka _ Stormwater Devices Swale

Rainwater Tank

A swale is a low tract of land. The term can refer to a natural landscape feature or a human-created one. Artificial swales are often designed to manage water runoff, filter pollutants, and increase rainwater infiltration. The swale concept has also been popularized as a rainwater harvesting and soil conservation strategy.

A rainwater tank is a water tank used to collect and store rain water runoff, typically from rooftops. Rainwater tanks are installed to make use of rain water for later use, reduce mains water use for economic or environmental reasons, and aid selfsufficiency. Stored water may be used for watering gardens, agriculture, flushing toilets, in washing machines, washing cars, and also for drinking, especially when other water supplies are unavailable In ground rainwater tanks can also be used for retention of stormwater for release at a later time.

Swales will present alongside all roads on the site to help with the control of stormwater run off and pollutants form the road. There will be a range of different sized swales on the site ranging from 1,000m sq. up to 3,00 m sq. depending on location and size of the road and footpath. A large range of natives plants will be used in and around the site such as , cabbage trees, oioi, carex. Mostly native grasses will be used, and plants the can live in both dry and wet environments.

All buildings on the site will have rainwater collection tanks either beside the buildings or underneath. All water collected from the buildings will be used for recirculation though the building saving on water being brought into the site.

The size of the rainwater tanks will depend on the size of the building and number of people/ apartments per building. The majority of the tanks will start at around 100,00litres and go up to 500,000litres.


Karaka _ Stormwater Devices Wetland A wetland is a land area that is saturated with water, either permanently or seasonally. Primarily the thing that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation that has adapted to its unique soil conditions,. Wetlands play a number of roles in the environment, principally water purification, flood control, and shoreline stability. Wetlands are also considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal life. A number of wetlands will be present on the sire for control of stormwater from impervious surfaces. Helping to filtrate and store water and to help create natural habitats for native fauna

Rain Garden A rain garden is a planted depression or a hole that allows rainwater runoff from impervious urban areas such as roofs, driveways, walkways and parking lots the opportunity to be absorbed. This reduces rain runoff by allowing stormwater to soak into the ground, as opposed to flowing into storm drains and surface waters which causes erosion, water pollution, flooding, and diminished groundwater. They can be designed for specific soils and climates. The purpose of a rain garden is to improve water quality in nearby bodies of water. Rain gardens can cut down on the amount of pollution reaching creeks and streams by up to 30%. Rain gardens will be present around all buildings, courtyards and public spaces. These will help to control and filtrate water from the surrounding areas.

There will be a range of different sized wetlands on the site ranging from 10,00 m sq. up to 50,000 m sq. depending on location and number of impervious surfaces around the specific area.

The size of the rain gardens will vary depending on location, but each one will be designed to manage a 2year rainfall event in its location.

A large range of natives plants will be used in and around the site such as flax, cabbage trees, oioi, carex, etc.

The range a plants that will be used include carex, oioi, cabbage trees, flax(in some places). These plants will help to absorb some of the water and filtrate any pollutants.


Karaka _ Conclusion With all of these stormwater devices that I have chosen to place on the Karaka site, I feel that these will all work together to help create a sustainable subdivision that is able to control and maintain a large majority of its water needs and obligations. Water will be able to be controlled and filtered on site enabling cleaner water to be put back into the environment helping to keep streams, rivers and he coastal edge (Manukau Harbour) in a clean and safe state. Ensuring that native flora and fauna is able to not only survive but thrive in the area. The aim to create a design that is able to look after and control its own water and stormwater needs was a key issue and has been resolved with a wide range of LIUDD features and principles that have been applied to ensure this is achieved and can be completed accurately and be done with the confidence that it will work, even if you get a 2year rainfall.


Karaka LIUDD  

Looking at stormwater and LIUDD at the proposed Karaka development.

Advertisement
Read more
Read more
Similar to
Popular now
Just for you