3.2.3.5 - Urban Drainage + Case Study: SUD Olympic Park, London Flashcards
What is interception?
When precipitation lands on buildings, vegetation, concrete, etc before it reaches the soil. Storage is temporary, often quickly evaporated
WHat is vegetation storage?
All the moisture in vegetation at one time
What is surface storage?
Total volume of water held on earth’s surface in lakes, ponds and puddles
WHat is groundwater storage?
Water in underground permeable rock strata
WHat is channel storage?
Water held in a river or stream channel
HOw can flooding be increased in urban areas?
If run off from roofs and paved areas is piped into waterways
WHat are SUDS?
Sustainable Urban Drainage Systems
What do SUDS aim to do? (3)
- Control the quality and rate of runoff from a development
- Improve the quality of runoff
- Enhance the nature conservation, landscape, and value of the site and surroundings
What are permeable pavements?
Pavements made of porous material such as concrete blocks, porous asphalt, and crushed stone
Where does water go from a permable pavement?
It may infiltrate directly into the subsoil or be stored in an underground reservoir before soaking into the ground
What are swales?
Shallow ditches with gently sloping sides that can be built into the landscape
What are the advantages of swales? (4)
- They provide temporary storage for stormwater
- Reduce peak flows
- Facilitate filtration of pollutants
- Encourage microbial decomposition
How can green roofs act as SUDS?
They reduce flow rates and improve water quality, as well as improving insulation
WHat are infiltration trenches?
Stone filled resevoirs to which stormwater run off is redirected
HOw are pollutants removed from infiltration trenches?
By absorption, filtering, and microbial decomposition in the surrounding soil
WHat does the type of SUDS in place depend on? (4)
- The pollutants present in run-off
- The size of and drainage strategy for the catchment area
- The hydrology of the area and infiltration rate of soil
- The presence of Groundwater Source Protection Zones or contaminated land
WHat do SUDS aim to do?
Drain surface water in a manner that will provide a more sustainable approach than what has been standard practice of re-routing run-off through a pipe to a watercourse
Where is the Olympic development located?
Statford, east London
WHat does the Olympic park house?
The velodrome, aquatics centre, Copper Box and Riverbank Area
What was the site used for formerly?
An industrial/ commercial development as a depository for building rubble from properties demolished during WW2
Why was infiltration previously reduced?
Due to high levels of contamination
What was employed around pedestrianised areas?
Porous asphal stris to collect run off
Where was water taken from the asphalt strips?
Into granular trenches below which contain perforarted pipes, then draining into catchpits and finally watercourses
What was the main feature of the park in terms of SUDS?
The wetlands area
What other strategies were employed?
Swales, filter strips and small volume balancing ponds
Where was rainwater harvesting employed?
The velodrome and Copper Box
What was intended for the wetlands?
To be a wildlife haven for plants and animal, with habitats crated for otters, herons and water voles
What was taken into account when the SUDS were designed?
The potetial impacts of climate change
What were given appropriate methods of treatment?
Sources of surface water contamination
How could the SUDS system be improved?
BY considering eleements such as meltwater from snow or ice
What was ensured during the construction of the system?
The safe operation and maintenance of the system
