The design capacity of the Jubilee River is 215 cumecs, actual capacity about 180 cumecs.  The channel sustained significant damage on first use in January 2003 and is still unable to carry its design capacity.  Please see the expert view of Mr P Ackers below:

Extract from 1992 Maidenhead, Windsor and Eton Flood Alleviation Scheme Public Inquiry - Report to Minister.

15.  Further aspects of hydraulic performance

15.1. It would be very embarrassing to all concerned if the intended discharge capacity of the FRC ⁽¹⁾ was not achieved.  Thus the hydraulic computations are particularly important, and in this context the sensitivity of the channel to the roughness coefficients used and the method of dealing with two-stage channels implicit in the modelling are dominant issues.

This is the largest fluvial flood alleviation scheme ever to be carried out in the Thames region, and any deficiency in capacity would bring wide-spread – and justified – criticism.  It would be the largest man-made river to be created in the UK with full regard to the latest policies regarding environmental enhancements.

The question of the flow capacity likely to be obtained is not an issue that can be clouded over in the hope that design tolerances could later explain away any deficiency.  It is my firm view that there is no room for retaining optimistic assumptions in the hydraulic design:  in view of the novelty and scale of environmental enhancements proposed, some conservatism, some consideration of tolerances on assumptions is necessary.

Assessor: P Ackers - M Sc(Eng) FCGI FICE MIWEM MASCE

⁽¹⁾ [Flood Relief Channel now called the Jubilee River]  Jubilee River - MAP (EA) 163Kb.pdf   

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