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WEST QUAY FORENSIC REPORT - BUT DOES IT HOLD WATER?

posted 14 Aug 2012, 19:16 by Westover Labour
Tonight the long awaited Forensic report into the wall collapse of Carnival Night November 4th 2011 was finally presented by investigators Capita Symonds to an eager audience of residents and traders who have suffered for 9 months and simply wanted to know who was responsible, what compensation was available and what measures were put in place to stop it happening again.

In summary we discovered that the wall collapse was apparently 'an accident waiting to happen' with a 'mish mash of materials through the years providing an unstable  subsurface' and 'patched up repairs and ill fitting adaptions to existing structures  dating back to 1726' and the original 'Bodge the Builder', James Duke of Chandos, who had instigated the thin original outer curtain wall being built on unstable surface and on in particularly on a slope. 

We discovered that works by Wessex Water in 2008 and in the summer of 2011 might have contributed to the further undermining of the subsurface, that repairs to the original wall had included ill-fitting concrete 'in-fills' on quayside  stairwells and  that a survey by the Environment Agency in September 2011 revealed cracks on the quayside indicating some movement in the wall pulling it away from the pavement. 

We further learnt that the major rains which culminated on carnival night with a substantial flooding of West Quay  behind the wall and that during this period drains couldn't contain the deluge . To make matters worse we discovered that the Wessex pumps failed at a crucial time. On top of this there was the discovery , without explanation, of a severed clay pipe near the point of the wall break

Wessex says 'claims will be dealt with'

From the residents point of view there was welcome news when, under pressure of constant questioning from the floor and heart breaking stories of ruined businesses ,  the Wessex Water rep announced that if "any one had claims relating to either the flood of Carnival night or the subsequent flood of Jubilee day, they were invited to submit them and  Wessex would  deal with them".

5 factors which could have contributed to wall collapse

Regarding the crucial wall break, answers were less clear. Robin Sanders outlined 5 potential factors that taken together could all have contributed to the wall collapse 

Flooding along West Quay as a result of the lack of a direct outfall to the river for collected surface water, blockage of gullies due to detritus swept in by the intense rainfall at the start of the 4 November 2011 rainfall event, and the blockage of surface water pipes leading from the gullies to the main sewer along West Quay.

 Probable rise in groundwater level as a result of the rainfall event, the severance and removal of section of surface water pipe, possible leakage from the branch sewers at the junction of Castle Street and West Quay, and the probable restriction of groundwater flows by the buttresses installed in 1973.

 The probable entrance of water into the ground between the granite setts in the drainage channel beside the river wall raising groundwater pressures on the wall.

 Possible erosion of the river bed and support to the toe of the wall due to a likely increase in flow rates as a result of the gradual restriction of the river width as accretion has occurred on the east bank.

 The exacerbating effect of the river‟s low tide level, which reduced support in front of the wall.


Other factors investigated included the build up of leaves in the drains-largely from trees around autumnal Kings Square, combined with alien matter dumped in them by the public-but it was determined that these were cleaned regularly enough despite an examination after the event showing 7 of the 12 gullies blocked.

There was also the question of the 2008 sewer adaptations by Wessex Water which reduced the inner pipe within the main drain which runs down the centre of Castle Street. Several residents pointed to the surcharge of water backing up into homes in Castle street which gave evidence to this.

un-answered questions

Residents were less than impressed with the many unanswered questions 
*Could they say whether the pumps failed before or after the wall break? - for some reason they couldn't although they had 'telematric reports of the pump failures' and had 'identified the wall collapse as 16.25 on 4.11.2011'. 
*What was the cause of the broken nearby clay pipes? - They didn't know . 
*How could the second flood of Jubilee Day in June have happened only 6 months after the first? - "The pumps were not as efficient as we'd have liked" said Wessex "The second flood is one we'd have liked to have avoided". Residents heartily agreed...
*What was the capacity of the pumps? asked one resident. He was answered by another "Pumps that fail within 15 seconds have NO capacity."

What Next????

So what would the 4 Agencies, who acknowledged they had agreed an approximately equal commitment to the wall repair, but with Somerset doing the works, now do to help the residents and traders? 

Would Sedgemoor remove the Council Tax obligation and back date this? Alison Griffin said 'she'd look at this option'. 

Would the agencies now urgently set up a hardship fund with equal contributions to deal with these problems and seek redress themselves from any future claim to recoup the monies advanced ? SCC Portfolio Cllr Harvey Siggs said 'he'd talk to the leader of council and chief executive about this idea." 

Was there a robust inspection regime now in place to ensure the entire wall was safe and the collapse wouldn't simply recur? There essentially wasn't.

Incredibly, the key question was revealed in  point 206 of the report where Mr Sanders states  "In my view the owner of the wall should have taken reasonable measures to ensure that the alterations would not lead to potential failure. However, I am aware that the matter of who owns the wall remains unresolved."

The meeting ended with the report on the table and an offer to meet with the West Quay Action Group to discuss a way forward after people had taken the time to go away and read it.

People can read the report on line on the Somerset county web site. below.
www.somerset.gov.uk
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