This attenuation feature has been in the news. The following pdf’s relate:-
In the second pdf, the final report, there are 31 instances of the word ‘natural’, 18 of ‘natural process’, 42 of ‘SUDS’, zero of ‘NFM’, zero of ‘Natural Flood Management’, 7 of ‘filter-strips’ as hydrologic features, but with no reference to filter strips as hydrodynamic tools.
As an alternative to inundation, flood defence ‘ponds‘ engineered dry will be agriculturally productive – at least until the overspill of a 30-40RP uninsurable loss-event – with downstream low-lying areas defended in the meantime by diffuse hydrodynamic green reservoirs (harnessing the NFM capacity of the upstream floodplain). Attenuation therefore, ‘point’ or ‘diffuse’, presents options and useful benefits to operating authorities, but, in general terms, the more diffuse, the less the impact.