River Quaggy (C.S)

Background
1. Small river in London, UK
2. 17km long
3. Source: Locksbottom, Farnborough
4. Lower area it becomes an urban river
  1. Flows in-between houses
5. Upstream it is more natural and not urbanised
6. One of the Thames smaller tributries
7. The mouth of the river meets at River Ravensbourne
8. Part of the Ravensbourne catchment area
Regime of River Quaggy
1. Changes in the discharge over a period of time at a particular point
2. V responsive regime
  1. When it heavily rains the discharge in the river quickly increases
3. No significant artificial influences
  1. No dams etc
4. 1995: significantly high flow all year round
5. 2005: lower annual discharge, peak flow in Nov
6. Average daily flow has fallen since 1995
Flood Event
1. Worst event was Christmas Eve 2014
2. Was London's worst winter flood event
3. Quaggy burst its banks , inundating 22 homes
  1. Another 20 homes had flooded gardens
  2. Allotments and sports ground flooded
4. A month's worth of rain in 24hrs
  1. 50mm in 25hrs
5. High winds blew branches and trees into the river causing to block the trash gate ∴ it bursts its banks
Flood control (Mitigation)
1. Attempts in the past to mitigate flood events
2. Between 2003+2006, Environmental Agency (EA) installed trash gate as part of £11.8 Mil flood mitigation scheme to stop debris collecting @ culvert's entrance
3. EA built two small reservoirs to collect flood water + protect homes

Resource summary

	Created by Charlotte Willis about 6 years ago