1.5.1 Urban drainage

Question 1

What do SUDS stand for?

Answer 1

Sustainable Urban Drainage Systems

Question 2

What do SUDS aim to do?

Answer 2

Imitate natural drainage systems, rather than channelling water through pipes and drains.

Question 3

Types of SUDS

Answer 3

• Wetlands and ponds
• Permeable paving
• Swales
• Dry basin / detention ponds
• Tree pits
• Rain gardens
• Bioretention gardens

Question 4

What are the advantages of using SUDS?

Answer 4

• More methods are aesthetically pleasing.
• Multipurpose – Can act as a recreational space.
• Low maintenance costs.
• Decreased risk of flooding.
• Improves water quality, reduces water pollution.
• Water storage, reduces potential impacts of droughts.
• Can be used as a public space.
• Increased biodiversity.

Question 5

What are the disadvantages of using SUDS?

Answer 5

• Most methods take up a significant amount of space that could otherwise be used for development.
• Expensive to initially install.
• Health and safety.

Question 6

What is the example of tree pits?

Answer 6

Derby Train Station

Question 7

What is the example of permeable paving?

Answer 7

LA Zoo

Question 8

What is the case study for SUDS?

Answer 8

Lamb Drove, Cambourne

Question 9

What was the aim of the Lamb Drove development?

Answer 9

• Showcase practical and innovative sustainable water management techniques within new residential developments
• Demonstrate that SUDS are a viable and attractive alternative to more traditional forms of drainage and to deliver practical solutions for new housing areas

Question 10

What SUDS were used in Lamb Drove?

Answer 10

• Water butts - to collect roof water for garden irrigation
• Permeable paving - allowing water to enter porous storage zones and to filter out pollutants.
• Green roofs - to reduce and treat runoff
• Swales (shallow open channels) - to collect all excess water from the site, further slowing the flow and continuing the water treatment process
• Creation of detention basins and wetlands in open spaces to slow down the runoff rate and store water on a temporary short-term basis during extreme (flood) events.
• A retention pond for final storage of water before being released to a drainage ditch beyond the development site.

Question 11

What did the Lamb Drove case study show about SUDS?

Answer 11

This case study showed SUDS are cost-effective – both construction and ongoing maintenance costs have been 10 per cent less than conventional pipe drainage systems.

There has also been a substantial improvement in the biodiversity, ecology and subsequent quality of life at Lamb Drove compared to typical residential developments. The use of SUDS has also resulted in an improved quality of water leaving the site compared with traditional piped drainage systems.

Question 12

River restoration

Answer 12

River restoration refers to a large variety of ecological, physical, spatial and management measures and practices.

There are aimed at restoring the natural starts and functioning of a river system in support of biodiversity, recreation, flood management and landscape development.

Question 13

Case study for river restoration

Answer 13

Cheonggyecheon river

Question 14

History of the Cheonggyecheon river

Answer 14

• The Cheonggyecheon is a small stream which runs through Seoul’s CBD.
• After the Korean war, Cheonggyecheon was regarded as “an obstacle to economic growth and urban development” and was covered by a six-line highway between 1958 and 1961.
• In 2003, a 2 year $281 million redevelopment project launched to restore the river into an 5.8km ecologically sensitive green pedestrian corridor.

Question 15

Reasons for the restoration of the Cheonggyecheon river

Answer 15

• The South Korean government had a bigger emphasis on health, sustainability and social responsibility.
• The aging motorway above was a health and safety risk.
• The government wanted to improve connectivity between north and south of the city which the motorway divided.

Question 16

Attitudes and contributions relating to the restoration of the Cheonggyecheon river

Answer 16

• South Korean President Lee Myung Bak included the restoration in his bid to be Mayor of Seoul.
• Transportation experts worried removing the motorway will lead to congestion elsewhere in the city.
• The Cheonggyecheon Restoration Citizens Committee of professional groups gauged public opinion and organised public opinion sessions.
• Local businesses were concerned it could damage their livelihoods.

Question 17

Evaluation of the Cheonggyecheon river restoration project

Answer 17

The restoration of the Cheonggyecheon has became very popular with around 18.1m visitors by the end of 2008.
Public facilities have encouraged diversity of cultural programming.
The project has reduced temperatures by 2.5 ° C.

• Economic – The area has seen an increase in investment, this has led to new residential development and the number of businesses nearby has risen.
• Traffic – Public transport use has increased, and the walkways have become an popular alternative to driving.
• Climate – The removal of cars from the area has caused temperatures to decrease by 2.5oC (and a cooling wind corridor has been created).
• Environment – The steam has improved biodiversity and has re-established lost habitats
• Inclusive design – After a string of protests, lifts were provided at 7 locations and providing free wheelchairs. However, the local area is poorly lit and has uneven surfaces meaning it is difficult for people with disabilities or visual mobility.