Project: M74 Raith Interchange Water Environment (Drainage & Hydrology)

Central Scotland
Transport Scotland
Part of £415m CAPEX (DBFO)

the commission

M74 Junction 5 is an integral link in the Central Scotland trunk road network. The improvements provide free flow movement for A725 traffic, reducing queuing on approach roads at peak periods and allowing traffic on the surrounding all-purpose road network to move more freely.

Transport Scotland awarded Mouchel Consulting and Fairhurst Joint Venture (MFJV) the commission to develop design solutions for the proposed improvements, including production of the DMRB Stage 2 and 3 Environmental Assessments, Environmental Statement, Specimen Design and contract documentation.

MFJV also acted as Scottish Ministers Site Representative; auditing contract compliance and monitoring construction activities.

our input

As the junction sits in the floodplain of the River Clyde, adjacent to a nationally designated site of special scientific interest, environmental considerations were integral to the design. This specifically involved:

  • Developing drainage provision in line with the Design Manual for Roads and Bridges (DMRB) and incorporating Sustainable Drainage Systems (SUDS);
  • The inclusion of floodplain attenuation in the scheme to compensate for the loss of existing storage;
  • Provision of flood protection measures to ensure continual effective operation of the junction in extreme flood events;
  • Watercourse realignment and culvert design on affected watercourses in line with CIRIA best practice guidance.

Effective design development was informed through ongoing consultation with the Scottish Environment Protection Agency (SEPA), ensuring compliance with the Water Environment (Controlled Activities) Regulations 2005 (CAR).

Additional services were provided in preparing the CAR application and other pre-tender documents, such as the Specific Requirements and Watercourse Notices.

Water Engineering