ESP Autumn 2006 Newsletter
ST MELLONS LINK ROAD – CARDIFF
Over the winter of 2005/2006, ESP completed a site investigation and assessment for a major new highway scheme under our partnering agreement with Cardiff Council. The scheme is set to transform transport links in the east side of Cardiff. The proposed route layout begins at Wentloog Corporate Park, extending approximately 2km northeast across water meadows towards St Mellons Business Park. Part of the scheme incorporates an embankment 7m in height is required to take the proposed road over the Swansea to London Railway.
The project required >£100k of investigation which was delivered on-time and on-budget. The site forms part of the Severn Levels with deep deposits of clays and peat. Historically, major earthworks projects have suffered serious disruption owing to delayed consolidation of these soft deposits. Protection of water quality is also a major consideration in the area. In response to over-riding programme constraints we identified a number of strengthening measures with different balances between expense and speed of construction. These allowed for construction periods ranging from 3 to 24 months.
HYDROGEOLOGICAL IMPACT ASSESSMENT – YEMEN DESERT
ESP recently won a contract to undertake a hydrogeological assessment of an area of desert in Yemen to assess potential impacts of proposed infrastructure associated with hydrocarbon prospecting. Matthew Eynon, an Associate of ESP, undertook the works over a fortnight which involved nearly two weeks of studies carried out in the desert under the protection of a Yemenese Army Escort.
MERTHYR VALE RENEWAL AREA
In our Spring 2005 newsletter, last year, we introduced our work on the Merthyr Vale Renewal Area. This project involves a major residential development on the site of the former Merthyr Vale Colliery, which was reclaimed by coal recovery operations in the 1990s. In addition, a number of existing houses over 100yrs old, which are adjacent to the River Taff and prone to severe flooding, are to be relocated/rebuilt on higher ground.
Planning permission was granted in autumn of 2005 and subsequently the case was “called-in” for inquiry by the National Assembly for Wales. The reasons for this include:
- The visual and environmental implications of the proposed development;
- Risks posed by potential flooding from the River Taff.
ESP have been engaged to act as expert witness to the Inquiry on Environment, Flood Risk and Engineering Solutions.
Our proposals for the area include improving the river bank environment and creating wildlife corridors, with a particular emphasis on protection of otters and bats. We have included channel improvements to reduce ongoing maintenance and create new wetlands for wildlife. Channel widening is proposed and, by setting the bed level of the widening at about the 50 year flood level, habitat enhancement will be achieved together with flood alleviation.
Building new flood protection banks is not sustainable. They can increase the impact of extreme floods more severe than they are designed for. Our sustainable solutions include local land raising and remodelling parts of the river.
The engineering challenges at Merthyr Vale include: replacement of an existing river crossing; phased introduction of a new foul sewer system so it does not overload an existing siphon which has limited capacity; and minimising highway noise impact on a new school.