CES/AES Software









Download the CES/AES Standalone software!

Any software that is made available to download from this server ("Software") is the copyrighted work of the Environment Agency, Scottish Government, Rivers Agency Northern Ireland and Wallingford Software Ltd. and/or their suppliers. Use of the Software is governed by the terms of the end user licence agreement, which is included with the Software ("End User Licence Agreement “ or “EULA"). An end user will be unable to install any Software unless he or she first agrees to accept the terms of the EULA.


  1. CES User Manual (pdf, 4.46MB)
  2. AES User Guide (pdf, 2,29MB)
  3. Afflux Advisor: User Guide and Technical Reference(pdf, 1,67MB)
  4. CES Development supporting documentation
  5. AES Development supporting documentation

Frequently Asked Questions

Roughness and conveyance - technical questions

Q: How is the unit roughness derived?

Q: What exactly is the definition of "conveyance"?

Q: Will the unit roughness value be larger or smaller than the Manning n values?

Q: How do I convert from a unit roughness value to a Manning n value?

Q: Is it necessary to have a value for all the components making up the unit roughness value?

Q: If the spatial roughness description is altered, will this influence the cross-section water level?

Q: Does the CES/AES take account of losses due to changes in shape of consecutive cross-sections?

Q. Can you explain how the effect on flood level of local retention of in-stream habitat / plants can be estimated?

Q.Why is there no time varying roughness for some of the vegetation types?

Q: Are the CES/AES water levels appropriate for tidally influenced rivers?

Q: Can the CES/AES be used for alluvial streams?

Q. What is the link to the River Habitat Survey, and its relevance?

Backwater technical questions

Q. Can the flow in a section go super-critical?

Q: When I view my bank markers on the plot of the longitudinal section they are not at the correct section locations - why is this?

Q: In some instances when I plot a backwater, with the same inputs as before, I get different results – why is this?

Q: When I run the backwater calculations, in some instances, the cross-section user entered slopes are updated – why is this?

AES technical questions

Q. What exactly is the definition of "afflux"?

Q. How can the effect of waterway blockage be estimated ?

Q. What is the correct way to add a structure to a river reach?

Support queries

Q. Why can’t I telephone someone for support in using the CES/AES Stand-alone that I’ve downloaded?

Contact Details

The CES/AES Standalone and Afflux Advisor are provided “as is” and are not formally supported.  However, users are welcome to submit general feedback, issues and questions to: support@innovyze.com and we will respond where possible. 

We recommend that new users should attend a training course.


A standard one day training course in the use of the CES/AES Standalone is available. This is run periodically at HR Wallingford and can be held elsewhere by arrangement.

For further information on the standard one day training course as well as dedicated courses tailored to specific applications (e.g. channel maintenance, scheme design, flood risk), please contact Caroline Hazlewood.

Last updated: June 2013