Urban Drainage

Question 1

What are urban areas covered in?

Answer 1

Impermeable materials

Question 2

Why are urban areas covered in impermeable materials?

Answer 2

Infiltration is low so replenishment of groundwater stores is slow.

Question 3

What is catchment management?

Answer 3

A way of managing rivers and improving drainage systems by looking at the whole river catchment

Question 4

What does catchment management aim to do?

Answer 4

Aim to minimise issues such as flooding, drought and water pollution and erosion.

Question 5

What are 2 main methods used to manage river catchments?

Answer 5

Hard engineering
Soft engineering

Question 6

What is hard engineering?

Answer 6

This involves man-made structures such as dams which are often used to prevent flooding

Question 7

What are 2 disadvantages of hard engineering?

Answer 7

Expensive
Can disrupt natural systems

Question 8

What is soft engineering?

Answer 8

This uses knowledge of the river basin and its processes to try to work with nature.

Question 9

What does soft engineering involve?

Answer 9

Land use management

Question 10

What are SUDS?

Answer 10

Sustainable Urban Drainage Systems

Question 11

What do SUDS aim to do?

Answer 11

Manage rainfall near to where it lands and allows it to infiltrate mimicking nature

Question 12

What are swales?

Answer 12

Vegetated tranches

Question 13

What do swales do?

Answer 13

Increase interception of rainfall and retention basins store water

Question 14

Why are SUDS more sustainable than traditional methods?

Answer 14

They work with the natural environment to improve drainage and water quality.

Question 15

What does river restoration and conservation aim to do?

Answer 15

To restore river systems to a more natural state.

Question 16

What is one area that is restoring its rivers?

Answer 16

Enfield in North London

Question 17

What are 2 disadvantages of work of Enfield?

Answer 17

Increased surface runoff so flood risk is higher
Water pollution directly into. rivers

Question 18

Why does urban drainage need to happen?

Answer 18

Rainfall run off in cities that need to be dealt with to prevent flooding

Question 19

What is an example of urban drainage? Culverts being used

Answer 19

LA river

Question 20

What are issues with urban drainage?

Answer 20

Water is transferred quickly to rivers, increasing flooding and reducing infiltration
Less ground water available

Question 21

What does SUDS do? 3 points

Answer 21

Enhance wildlife
Reduces risk of flooding
Acts as an amenity for the community

Question 22

What is an issue with old systems?

Answer 22

Traditional drainage basins cannot control poor runoff quality

Question 23

What are permeable surfaces?

Answer 23

Refers to a surface that is porous in nature so that the rainwater falling on the surface/run-off penetrates into the pores and stored in a reservoir

Question 24

What is an advantage of permeable surfaces?

Answer 24

Runoff is reduced

Question 25

What is a disadvantage of permeable surfaces?

Answer 25

Can be clogged up

Question 26

What are infiltration surfaces?

Answer 26

Linear ditches that collect rain water from adjacent surfaces

Question 27

What is an advantage of infiltration surfaces?

Answer 27

Helps preserve the natural water balance of a site

Question 28

What is a disadvantage of infiltration surfaces?

Answer 28

Not appropriate for dense urban areas

Question 29

What are swales?

Answer 29

Very shallow channels that are used to collect and/or move water and also removes pollution

Question 30

What is an advantage of swales?

Answer 30

Reduces run-off

Question 31

What is a disadvantage of swales?

Answer 31

Can be clogged with leaves

Question 32

What are detention basins?

Answer 32

Surface storage basins or facilities that provide flow control through attenuation of stormwater runoff

Question 33

What is attenuation?

Answer 33

Process of storing stormwater then releasing it slowly

Question 34

What is an advantage of detention basins?

Answer 34

Enhanced society capacity Can provide cooling

Question 35

What is a disadvantage of detention basins?

Answer 35

Require a sizeable amount of land

Question 36

What are purpose-built ponds and wetlands?

Answer 36

A place in which the land is covered by water, salt either seasonally or permanently

Question 37

What is an advantage of purpose-built ponds and wetlands?

Answer 37

Healthy wetlands store carbon and slows the flow of water, cleaning it naturally and reducing flood risk downstream

Question 38

What is a disadvantage of purpose-built ponds and wetlands?

Answer 38

Waste can be an issue

Question 39

What is an example of somewhere built using SUDS techniques?

Answer 39

Dunfermline East Expansion (DEX)

Question 40

How are swales used at DEX?

Answer 40

The road system is drained using filter drains and swales

Question 41

How are detention basins and wetlands used at DEX?

Answer 41

Water discharged into both