Some constituents have raised concerns that intense development around Colindale may have contributed to the flooding problems due to surface runoff. Have you conducted an assessment of this issue around Colindale?
Flood risk in the Silk Stream catchment is caused by a combination of river flooding and surface water flooding. The Environment Agency are working with Barnet on the Silk Stream carrying out an assessment of flood risk in Colindale. This includes reviewing both river and surface water flooding interaction and a range of measures to resolve this (see Mayor’s Questions 2019/17624 and 2019/17625).
Through my London Plan I require new development to achieve as close to greenfield run off rates as possible, through avoiding excessive hard surfacing and delivering green infrastructure that slows rainwater run-off. This policy aims to reduce the risk of local surface water flooding.
Barnet’s Surface Water Management Strategy for the Colindale area reported that the increased predominance of paving over front (and back) gardens is contributing to flood risk issues in the area. The recently launched third round of Community Green Space grants (see Mayor’s Question 2019/17626) offers opportunities for communities to receive funding to tackle local surface water flooding through green space projects.