Page 51 - Hillingdon SuDS DESIGN & EVALUATION
P. 51
approach 1 approach 2
inflow inflow Concept Design
rainfall rainfall
x x
area area
interception losses interception losses
other
attenuation long attenuation
storage term storage
losses
variable outflow outflow for 1in100 yr
from 1in1 to 1in100yr 2L rainfall event limited
greenfield runoff /sec to 2yr greenfield 46
rates /ha runoff rate
Approach 1 and Approach 2 - Discharge Requirements
1 in 1 year rainfall 1 in 100 year Long term
(maximum rainfall storage-
outflow rate) (maximum volume
outflow rate) control
Approach 1 1 in 1 year 1 in 100 year Yes
greenfield rate greenfield
rate
Approach 2 Qbar/ Qmed Qbar/ Qmed No
London Borough of Hillingdon SuDS D & E Guide © 2018 McCloy Consulting & Robert Bray Associates
