A Need for a New Flood Risk
Management Perspective
April 2018
CRAGG - Cumbria River Authority Governance Group
Full report on this link
April 2018
CRAGG - Cumbria River Authority Governance Group
Full report on this link
Sunday, 6 May 2018
Community Trust - A presentation
Blind faith, cynical scepticism or critical friendship?
A presentation
By John Kelsall
Chair Cumbria River Authorities Governance Group (CRAGG)
Chair Carlisle Flood Action Group
Board Member Cumbria Strategic Flood Partnership
Open Letter to Carlisle City Council- Southern Flood Plain
Open Letter to Carlisle City Council
It is evident that although we have engaged in discussion with Senior Council
Members and Officers about the flood risk posed by the Eden Bridge and
developments on the southern flood plain our warnings appear to have fallen upon
deaf ears.
The Carlisle Corporation deliberately occupied the flood plain for development from the mid 19th Century by first tipping-on then building- on the ox bow lake of the Eden’s south channel. This area includes much of The Sands Centre, Civic Centre, Corporation Road, Magistrates Courts, Police Station, Fire Station, Hardwicke Circus and the Malt Shovel (Ristorante Adriano) as well as a number of commercial developments the construction of which has compounded this serious error affecting the conveyance of the Eden River in flood in almost every decade since. When will the lessons of history and engineering advice be heeded?
Recent presentations to the Council Leader, the Deputy Chief Executive and the Scrutiny Committee, amongst others, have clearly explained that the designer of the A7 Eden Bridge, Sir Robert Smirke, did not only design the bridge with 5 fully open arches but also a further 5 arches of similar size to a causeway to convey the River Eden in flood when it reverts to a preferred straight line flow characteristic. It is our belief that the current bridge, on its own, is insufficient even in fully open section to convey the river quickly enough to prevent it backing up the flow and diverting water across Hardwicke Circus etc. which is its chosen route. It is clear, therefore, that the flood defences in this area are incorrectly positioned forcing the Eden into a dangerous “pinch-point”. The damming effect this creates not only spills over and around the bridge locally, causing considerable disruption, but also has the effect of raising the river peak level which compromises further the emergence of the River Petteril which then has a knock-on effect at Botcherby Bridge which becomes less effective at reducing levels at Melbourne Park.
In our on-going dialogue with the Environment Agency we have questioned the computer modelling at the bridge which suggested there was only a 0.5m differential between upstream and downstream sides at flood peak either side of the Eden Bridge when the Desmond flood was at its height. Eye witness testimony and photographic evidence suggest this to be no less than 1.5m and possibly much more. The EA’s consultants are yet to report back upon re-investigation of this evidence so it is foolhardy in the extreme to undertake any physical concept design commitments, even in draft, of an expansion to the Sands Centre until design flow rates and levels can be established with suitable additional contingency and firm design criteria. Indeed management of the flood risk to the City may determine that the functions currently served by the Sands Centre and surrounding buildings may require re- location in any event.
We fear that the news, as recently reported in the media, of the Council voting to push ahead with this scheme without a clear caveat to this issue is the potential birth of yet another public act of folly that will considerably increase the risk to the City of yet more major flooding. We urge the Council to step back from the brink of what could be a very expensive and grave error of aspiration with far reaching consequences.
Southern
John Kelsall
Chair
Carlisle flood Action Group
The Carlisle Corporation deliberately occupied the flood plain for development from the mid 19th Century by first tipping-on then building- on the ox bow lake of the Eden’s south channel. This area includes much of The Sands Centre, Civic Centre, Corporation Road, Magistrates Courts, Police Station, Fire Station, Hardwicke Circus and the Malt Shovel (Ristorante Adriano) as well as a number of commercial developments the construction of which has compounded this serious error affecting the conveyance of the Eden River in flood in almost every decade since. When will the lessons of history and engineering advice be heeded?
Recent presentations to the Council Leader, the Deputy Chief Executive and the Scrutiny Committee, amongst others, have clearly explained that the designer of the A7 Eden Bridge, Sir Robert Smirke, did not only design the bridge with 5 fully open arches but also a further 5 arches of similar size to a causeway to convey the River Eden in flood when it reverts to a preferred straight line flow characteristic. It is our belief that the current bridge, on its own, is insufficient even in fully open section to convey the river quickly enough to prevent it backing up the flow and diverting water across Hardwicke Circus etc. which is its chosen route. It is clear, therefore, that the flood defences in this area are incorrectly positioned forcing the Eden into a dangerous “pinch-point”. The damming effect this creates not only spills over and around the bridge locally, causing considerable disruption, but also has the effect of raising the river peak level which compromises further the emergence of the River Petteril which then has a knock-on effect at Botcherby Bridge which becomes less effective at reducing levels at Melbourne Park.
In our on-going dialogue with the Environment Agency we have questioned the computer modelling at the bridge which suggested there was only a 0.5m differential between upstream and downstream sides at flood peak either side of the Eden Bridge when the Desmond flood was at its height. Eye witness testimony and photographic evidence suggest this to be no less than 1.5m and possibly much more. The EA’s consultants are yet to report back upon re-investigation of this evidence so it is foolhardy in the extreme to undertake any physical concept design commitments, even in draft, of an expansion to the Sands Centre until design flow rates and levels can be established with suitable additional contingency and firm design criteria. Indeed management of the flood risk to the City may determine that the functions currently served by the Sands Centre and surrounding buildings may require re- location in any event.
We fear that the news, as recently reported in the media, of the Council voting to push ahead with this scheme without a clear caveat to this issue is the potential birth of yet another public act of folly that will considerably increase the risk to the City of yet more major flooding. We urge the Council to step back from the brink of what could be a very expensive and grave error of aspiration with far reaching consequences.
Southern
John Kelsall
Chair
Carlisle flood Action Group
Subscribe to:
Posts (Atom)