Culvert, screen and outfall manual - New CIRIA guidance

This webinar will provide an overview of the new CIRIA manual on culverts, screens and outfalls, the scope of which incorporates four previous documents on culverts, trash and security screens and drainage outfalls.


There are hundreds of thousands of culverts across the UK providing a means for railways, highways, canals, footpaths etc. to cross watercourses. Some of these culverts also have screens for security purposes or debris management. There are also numerous highway drainage outfalls.

Culverts, screens and outfalls are superficially simple structures, but they have the potential to restrict flow (causing flooding), can be more expensive to maintain than open channels or soakaways, and can adversely affect the aquatic environment and create new health and safety hazards. As a result, there is a presumption against the construction of new or replacement culverts.

Assessment of the hydraulic performance of a culvert, screen or outfall can be complex. This manual provides a number of methods from hand calculation to computer modelling to assist.

In service, a well-designed culvert or outfall may require little attention from an asset manager other than routine inspection and maintenance. It should also not require a screen. However, there are thousands of existing culverts, screens and outfalls across the UK, many where conditions have been significantly altered by urban development, climate change and concern about the quality of the natural environment. Problems of decaying structural fabric, sedimentation, blockage by debris, and inadequate capacity present an asset manager with a constant demand for assessment, rehabilitation, repair and enhancement. Also, there are increasing environmental and potential liability pressures, driven in part by legislation, that require asset managers to examine options for improving the environmental, hydraulic and health and safety performance of culverts, screens and outfalls, including restoring the watercourse back to a more natural state by means of ‘daylighting’ and removal of screens that are no longer necessary.

This event will provide an overview of how the new manual will help understand, consider and address the above challenges.

It will also provide information on how to download this free manual.

This  CIRIA project was funded  by the Environment Agency, Network Rail, Highways England, Transport Scotland and written under contract to CIRIA by JBA Consulting and Mott MacDonald.

NOTE: A complementary webinar launching the new Environment Agency Blockage Management Guide is also being arranged.
See below for further details.

 Why attend

  • To understand how the new guidance helps with the design, assessment, modification and removal of culverts.
  • To understand the principal differences between the new guide and the CIRIA, Environment Agency and Highways England documents on which it is based


10:00  Introduction and background to project:  Owen Jenkins, CIRIA

10:10  Overview of document, - Jeremy Benn, JBA Consulting

10:30  Principal changes – Amanda Kitchen, Mott MacDonald

10:50 Questions and discussions

11:15 Close

Who should attend

Asset managers, consulting engineers and scientists, flood risk management practitioners, local authority, highway and drainage engineers, infrastructure planners, environmental professionals, regulators


Friday 13th December 2019
10:00 - 11:30

FREE for all to attend

Please sign in or create an account to register for this event.
The link to attend the webinar is strictly personal and should not be shared. 
CPD certificates will only be issued to attendees registered on our booking system 
prior to the webinar.
If you are experiencing issues registering for this event online please contact us on 
020 7549 3300  or 
Joining instructions will be sent 10 days before the webinar

Terms and Conditions
Click here for details of our terms and conditions that will apply.
Personal data is gathered in accordance with CIRIA's privacy policy.

Further information


 A complementary webinar is being arranged by the Environment Agency to launch the new Blockage Management Guide     
10th December 2019 (10:15- 11:15) 

To register to attend, please contact

For further information on CIRIA membership and other services, please contact:
Tel: 020 7549 3300
Fax: 020 7549 3349
13/12/2019 - 13/12/2019

Sign In to register