Page 91 - Hillingdon SuDS DESIGN & EVALUATION
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Approach 2
Where volumes cannot be managed to
predevelopment status, then outflow rate Detailed Design
should be controlled to a maximum of Qbar
rate (which is equivalent to a 1 in 2 year or
Qmed which is used by FEH methods) for all
rainfall return periods up to the 1 in 100 year
rainfall event plus climate change allowance.
This is the approach most commonly utilised
by industry at present due to simplicity of
analysis, but can result in a greater storage
requirement due to more restricted outflow
rates. (NSTS S6)
Riverside Court, Stamford.
Permeable pavement delivers a controlled flow of clean water to
landscape canal and rill features and to the River Welland.
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London Borough of Hillingdon SuDS D & E Guide © 2018 McCloy Consulting & Robert Bray Associates
