- Highway Design
- Drainage Design
- Drainage Modelling
- Sub-Consultant Appointment & Management
Homes and Communities Agency
Public Sector/Greenfield Development
The scheme delivered link road provision with re-routing of 2 km of Internal Drainage Board (IDB) 3 metre deep, by 9 metre wide land ditches for the Capitol Park industrial/commercial development in early 2016. The proposed scheme provided 60ha of developable land in Flood Zone 3 to create up to 3000 future employment opportunities for which the Homes and Communities Agency (HCA) were the client, with significant support received from the East Riding of Yorkshire Council, the IDB and the local community, and which was part funded by the European Regional Development Fund.
SCP were the lead designer in the delivery of the scheme, for which they designed all the Civil Engineering, Drainage, IDB Watercourse, Highways and managed their sub-consultants for delivery of the Geotechnical and Environmental works.
Through the delivery process, design development was considered from the outset, enabling design options to be agreed and captured in the detailed design, achieving best value for the client. A full approval process with the HCA was delivered for the design and construction processes, which was supported by the HCA, ERYC, and Goole and Airmyn IDB through delivery of the works.
The design development, sought to deliver design options that would deliver sustainable design solutions, considering the construction process, whilst seeking to minimise future maintenance.
A fundamental part of the delivery of the scheme, was the existing and proposed land drainage, which took the form of swales and ditches, which cut across and intersected the site. The existing drainage consisted of ditches of varying sizes, which were linked by varying size conduits, which acted as throttles.
On review of the existing ditches, and through consultation and coordination with the IDB, it was confirmed that the site flooded in parts of the site, as a result of the ditches was a regular occurrence due to the pipes acting as a throttle when in operation. To fully understand the problem, SCP analysed and confirmed the catchment areas for the existing ditches, and created a drainage model, to simulate the current on site conditions. This includes a catchment zone outside the site, of which we analysed the contributing connections in to the site.
Through this assessment, and early consultation with the Goole and Airmyn IDB, design optioneering was carried out to agree improvements to the design, and benefits to the overall scheme for both the delivery period, and the future maintenance of the scheme.
This was achieved through realigning the existing ditch network to achieve an alternative ditch alignment of a comparable lengths and volume. This enabled the piped connections / throttles to be removed from the network thereby mitigating the flooding and maintenance issues that were being realised on site.
To obtain best value for the scheme, innovative design solutions were considered at the outset, and realised through the delivery of the design, which included:
- Rerouting and design of the IDB ditch network through the site, to reduce the level of maintenance through removal of culverts within the ditches which created throttle points to the flows, achieving a saving in the region of £200,000
- Improved watercourse access to aid long term maintenance
- Modelling of the existing and proposed watercourse models
- Redesigning as opposed to retaining the existing ditches around the development site to support future employment opportunities.