Rapid assessment of surface-water flood-management options in urban catchments

Figures & data

Figure 1. Framework for surface-water intervention assessment.

Table 1. Parameter values for land-use types in CADDIES.

Type	Roughness (Manning’s n)	Infiltration (mm h^−1)
Urban	0.065	12
Green space	0.110	15
Building	0.300	0
Road	0.015	12

Table 2. Parameter values for intervention types in CADDIES.

Type	Roughness (Manning’s n)	Infiltration (mm h^−1)	Rainfall capture (mm h^−1)
Do Nothing	No change	No change	No change
Intervention A	No change	No change	20
Intervention B	No change	20	No change
Intervention C	No change	20	20
Intervention D	0.010	No change	No change
Intervention E	0.010	No change	20
Intervention F	0.010	20	No change
Intervention G	0.010	20	20
Intervention H	0.110	No change	No change
Intervention I	0.110	No change	20
Intervention J	0.110	20	No change
Intervention K	0.110	20	20

Figure 2. Peak flood depth for ‘do nothing’ simulation with the area of most extensive flooding highlighted.

Figure 3. Relative maximum flood depth for intervention scenarios in the urban area.

Table 3. Building-damage cost comparison in the highlighted urban area.

Rank	Intervention	Total damage (10^3) (GBP)	Damage cost reduction (%)
1	K	411	86
2	C	470	84
3	G	609	79
4	I	1040	64
5	A	1226	58
6	E	1301	55
7	J	1623	44
8	B	1818	38
9	F	1890	35
10	H	2625	10
11	D	2829	3
12	Do Nothing	2920