Working near water (Part 2 of 2)

Continuing on from Part 1 of 2, Working near water, we now consider the permit requirements for riverside developments. Any works within 8m of a main river or within the flood zone requires a Flood Risk Activities Environmental Permit.

3D cross section illustrating the 8m flood zone

3D cross section illustrating the 8m flood zone

The Riverside Pavilion at St Hilda’s front of College development, is positioned on the banks of the River Cherwell. Due to additional site specific complexities, it was agreed with the Environment Agency (EA) to develop a bespoke permit application. This involved a detailed method statement as part of the permit application process. This method statement was developed alongside Beard Construction. 

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As not all the sub-contractors were appointed at that stage, it was agreed to create a project method statement which sets out the principles of the construction of the pavilion, reflecting our environmental impact assessment conclusions. Detailed method statements were then submitted as construction activities progresses. Each of those detailed method statements were reviewed by us for compliance with the EA agreements.  

One such area of work that has been completed is the demolition of the existing river wall. Part of the civil sub-contractor Greenford’s method statement had to address how a temporary cofferdam with silt traps was created within the river bed to allow for safe demolition of the existing wall.

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Once the wall was demolished, the new wall was built using sheet piles. This construction method allowed for substantial loading of the wall for the piling of the Pavilion Building.

EAP 2 EA bespoke permit application River Pilled Wall.jpg

Due to the riverside setting, the sheet pile wall has perforations to allow ground water to flow through the wall. The top of wall follows the ground profile.

EAP 3 EA bespoke permit application River Pilled Wall.jpg

The new sheet piling is then stone faced. During construction the level of the stone support was changed to run flush with the water level. This change required a further bespoke EA permit.

EAP 4 EA bespoke permit application River Pilled Wall.jpg

It remains important to ensure the time period to apply for river permits with the EA is understood and considered in the overall project programme. Solid Structures have also recently been involved with EA river permit applications for Christ Church Punt Station, Asthall Manor Battery House refurbishment and Nuffield College refurbishment along Park End Street.