Drainage/Civil Engineering


TJA provides a strategic drainage view of large and small projects to contribute to the master planning of infrastructure. The drainage section utilises the latest design technology and is respected by the drainage authorities for our knowledge and ability in applying solutions to our clients needs.

TJA has extensive experience in all aspects relating to drainage and flooding and have undertaken a series of extensive drainage strategies for Clients to incorporate Sustainable Urban Drainage Systems to satisfy not only Client requirements but Environment Agency, drainage authorities and other organisations.

Areas of work undertaken include:

  • Pre purchase drainage advice.
  • Preparation and agreement of foul and surface water drainage strategies;
  • Determination of utility servicing strategies and procurement;
  • Surface water attenuation calculations and negotiations.
  • Consultation and negotiation with statutory authorities to secure technical approvals.
  • Building over sewer design and advice.
  • Sustainable Urban Drainage designs and advice.
  • Pumping station specification.
  • Water Authority negotiations.
  • Soakaway design and testing and advice.
  • Flood protection advice.
  • Drainage expert witness.

TJA staff have provided drainage advice for a wide range of developments throughout the British Isles including residential, retail, industrial, leisure and mixed developments.


Flood risk assessments are a statutory requirement of any new development over 1 hectare and, with the introduction of PPS25, play a large part in the layout and scale of a project. NLC have extensive knowledge and experience in the production of such drainage strategy plans and use their strong relationship with Environment Agency engineers to prepare cost effective designs for the most difficult of sites.

We have a great deal of experience in preparing Flood Risk Assessments (FRA) and employ the latest software packages (including Microdrainage, HecRas and Tuflow) in providing FRAs compliant with PPS25.this includes the preparation of Flood Risk Assessments, including breach analysis and two dimensional hazard modeling;


Civil engineering

The TJA Infrastructure team specialise in the design of infrastructure, including roads, drainage and sewerage systems, for national building firms, highway authorities and water companies. We are involved in developments of all sizes and are proud of the extensive and varied development experience of our staff who are able to offer a wide range of services, drawing upon their extensive and varied experience of working on development schemes within multi-disciplinary project teams. It is this breadth of experience which enables us to offer a wide range of transport and infrastructure services. It also means we are always able to see the bigger picture and consider implications outside our specialist areas of expertise.

We design for all standards of road, from rural roads through to urban distributor roads plus Section 38 housing estate roads. We provide guidance and support on link design, junction design, signs and road markings, and Section 278 works.

We specialise in detailed negotiations with highway authorities to enable our client’s sites to be connected with the developed highway infrastructure.

Each project requires a different group of services but these typically include:

  • Vertical and Horizontal Highway and Drainage Alignments designs and detailing including Contract documentation.
  • The production of a coordinated services drawings through liaison with public utility companies.
  • Drainage design
  • Terrain modelling and earthworks calculations using design software
  • Junction Design.
  • Site lines assessments.
  • S278 Agreements
  • S38 Adoptions.
  • Project management.
  • Contract documentation  ICE and NEC