December 2014
The latest report commissioned by Hertfordshire County Council into the Green Street Flooding has now been published.
The report looks at the impact modifying the embankment would have on the road.
The assessment has demonstrated that modification or removal of the embankment is beneficial in terms of reducing or removing the impounding effect causing accumulation of floodwater. However, no option is available to entirely remove flooding at the site in that any such option would result in a significant residual hazard to road users. “
Contrary to the letter from Sophie Williamson, Senior Flood Risk and *SuDS Officer at HCC quoted below, this report did not determine if the flood relief works carried out in Lower Road would be sufficient to cope with the addition of water drained from Green Street.
“All options would cause an increased flood hazard on downstream development downstream, the effect of which on could not be determined within the parameters of this study.”
In conclusion, if you remove the embankment between the road and the surrounding land some of the water will eventually drain away from the road but they were unable to assess the impact this will have elsewhere and anyway the road will remain a bit flooded.
The ultimate conclusion seems to be that any effective flood relief measures are going to involve the use of third party land.
It is possible that being in the middle of the festive period we have missed some of the subtleties of the report and that the new year will offer time for more sober reflection, but in the meantime our favourite bit of the 40 page report is:
The “Do Nothing” scenario offers no potential ability to provide flood protection to Green Street.
November 2014
Well it’s that time of year again, and since we’ve already had one serious downpour, we’re very grateful to County Councillor Christopher Hayward for keeping us up to date on his determined efforts to get the flooding matter resolved.
The Flood Management Team at Hertfordshire County Council (HCC) have commissioned a report to investigate the likely impact that the planned flood relief works in Green Street will both in Green Street and further down the hill.
In a letter to Cllr Hayward, Sophie Williamson, Senior Flood Risk and *SuDS Officer at HCC says,
“We need to ensure that any alteration to the earth embankment will not cause flooding to local residents downstream. The topography shows that the surface water flow path from Green Street should the embankment be removed may reach the centre of Chorleywood via Homefield Road and Orchard Road.
We also need to ensure that any flood flow route reaching the top of Homefield Road to the centre of Chorleywood will not compromise the Thames Water Flood Alleviation Scheme which we recently found out was built in 1999 located in Lower Road after the flooding of around 70 properties in 1992 and 1997.”
Whilst, on balance, it does seem very sensible to make sure that any works will not do more harm than good, it also seems increasingly unlikely that any works will be carried out before the next downpour.
To quote Cllr Hayward “We are all losing patience.”
*SuDs = sustainable drainage systems
Related Posts
Jan 2015 Green Street Flood Meeting
Feb 2014 The Ballard of Green Street
Feb 2014 Floods Call for Action
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