CUE - SUDS

Question 1

What does SUDS stand for?

Answer 1

Sustainable Urban Drainage Systems

Question 2

What is surface runoff like in urban areas?

Answer 2

Due to the impermeable surfaces used in urban areas e.g tarmac and concrete water cannot infiltrate into the ground

This means that surface runoff rates are higher in urban areas

Question 3

What is the storm hydrograph of an urban river like?

Answer 3

Precipitation is higher and more intense in urban areas. impermeable surfaces and drainage systems means that water is quickly channelled through man-made pipes to rivers and streams

Therefore, the storm hydrograph has a short lag time and high peak discharge. Therefore, the hydrograph is ‘flashy’

Question 4

What are the key componants to label on a flood hydrograph?

Answer 4

Peak rainfall
Lag time
Rising limb
Falling limb
Base flow

Question 5

What is catchment management?

Answer 5

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

It aims to minimise issues such as flooding, drought and water pollution, and erosion and to improve river systems

Question 6

What are the two main methods of catchment management?

Answer 6

Hard and soft engineering

Question 7

Give the advantages and disadvantages of hard engineering strategies

Answer 7

Advantages
Man-made structures e.g dams, floodwalls and reserviors prevent flooding and ensure water supply

Disadvantages
Expensive
Can disrupt tthe natural ecosystemse.g silt can be trapped behind dams increasing erosion downstream
They can alter wildlife habitats e.g dams can prevent the migration of salmon upstream

Question 8

Give the advantages and disadvantages of soft engineering strategies

Answer 8

Advantages
Cheaper
Uses knowledge of the river basin and processes to work with nature

Question 9

Give examples of hard engineering strategies of catchment management

Answer 9

River straightening
Embankments
Natural levees
River channelisation (lining straightened channels with concrete - reduces friction and the build up of silt)
Diversion spillways (flood releif channels that are controlled by gates for emergency use)

Question 10

Give examples of soft engineering strategies for catchment management

Answer 10

Afforestation
Riverbank conservation (to reduce bank collapse and lateral erosion)
Floodplain zoning
River restoration

Question 11

Give an example of catchment management and describe it

Answer 11

River Aire - Leeds
After severe flooding in 2015 the Leeds City Council and tthe Environmental Agency set up the UK’s largest natural flood management scheme —> afforestation along river channel

Question 12

What is the aim of SUDS?

Answer 12

To imitate natural drainage systems

Question 13

What do SUDS help to do?

Answer 13

Slow down suface runoff and reduce flood risk
Reduce risk of sewer flooding during heavy rainfall
Prevent water pollution
Recharge groundwater to help prevent drought
Provide valuable habitats for wildlife in urban areas
Create green spaces for people in urban areas

Question 14

Give some examples of SUDS

Answer 14

Permeable block paving
Raingardens (sloped area of land that can capture water and allow it to infiltrate into the ground)
Swales (shallow and broad vegetated channels which allow water to infiltrate and to remove pollutants)
Green roofs

Question 15

Give an example of a SUDS scheme

Answer 15

Stormwater (ongoing project) - a large sustainable drainage housing project in Leeds off 800 terraced houses and apartments. Located by the side of the River Aire

Has rain gardens, permeable paving, and green roofs

Question 16

Give the benefis and costs of the Stormwater project

Answer 16

Benefits
Helps protect people’s homes from flooding
Houses built high above river to withstand a 1 in 200-year flood so the risk of economic damage is reduced
Meadows and greenspace as part of the project can provide wildlife habitats

Costs
Project is costing 250 million

Question 17

Give an example of a river restoration and conservation project in a damaged urban catchment and descrivbe (why was it required, what was done)

Answer 17

River restoration and conservation of the River Lea in Enfield due to regular flooding in 2006, 2007 and 2008

Urban growth meant 9000 homes in Enfield were at risk of flooding from the River Lea and 10% of homes had wastewater pipes running directly into the river

SUDS was used to restore the area with wetland constructed to improve water quality, rain planters installed in schools to collect rainwater and manage the movement of water into drains, vegetated trenches to absorb runoff

Question 18

Who was involved in the Enfield project?

Answer 18

Thames 21 offered education sessions for local schools to increase engagement
Defra and Thames Water provided funding

Question 19

What were the sucesses and failures of the Enfield project?

Answer 19

Successes
SUDS reduced ammonia levels by 67% and nitrogen levels by 43%
Population of eels and insects has increased
Flood risk reduced with no significant flooding in 2013 and 2014

Failures
Pollution and litter remain to be an issue