Damage Type | Methodology/Source | Brief Description of
Approach | Values Taken from Source | Key Sources of Uncertainty | Other Notes/Comments | | | | |
Low | Mid | High |
Damage to building fabric | Multi-Coloured Manual | Applies to residential properties (per
property) LOW: 1 in 10 year flood, mean depth 0.2m
above floor level MID: 1 in 50 year flood, mean depth 0.4m
above floor level HIGH: 1 in 100 year flood, mean depth 0.5m
above floor level | £6,110 | £8,650 | £9,350 | Based on average for all residential
properties; flood duration <12 hours | May 2002 prices - need to be updated | | | | |
Damage to household inventory items | Multi-Coloured Manual | Applies to residential properties (per
property) LOW: 1 in 10 year flood, mean depth 0.2m
above floor level MID: 1 in 50 year flood, mean depth 0.4m
above floor level HIGH: 1 in 100 year flood, mean depth 0.5m
above floor level | £16,250 | £17,680 | £18,120 | Based on average for all residential
properties; flood duration <12 hours | May 2002 prices - need to be updated | | | | |
Damage to services in commercial
properties | Multi-Coloured Manual | Based on values per property, using High
Street Shop (211), with typical area of 550m2,
DDBasic depth-damage data LOW: mean depth of 0.2m MID: mean depth of 0.4m HIGH: mean depth of 0.5m | £14,480 | £34,784 | £56,981 | Used High Street Shop as figures in Tables
5.6 and 5.7 give very high numbers when
multiplied by typical areas | Values are still high (per property) and may
over-estimate damages - Hotel (511) gives lower
values, but pub, café all are much higher | £109,383 | £308,097 | £511,102 | |
Damage to moveable equipment in commercial
properties | Multi-Coloured Manual | Based on values per property, using High
Street Shop (211), with typical area of 550m2,
DDBasic depth-damage data LOW: mean depth of 0.2m MID: mean depth of 0.4m HIGH: mean depth of 0.5m | £32,188 | £95,166 | £159,494 | Used High Street Shop as figures in Tables
5.6 and 5.7 give very high numbers when
multiplied by typical areas | Values are still high (per property) and may
over-estimate damages - Hotel (511) gives lower
values, but pub, café all are much higher | | | | |
Damage to fixtures and fittings in
commercial properties | Multi-Coloured Manual | Based on values per property, using High
Street Shop (211), with typical area of 550m2,
DDBasic depth-damage data LOW: mean depth of 0.2m MID: mean depth of 0.4m HIGH: mean depth of 0.5m | £40,874 | £109,590 | £173,393 | Used High Street Shop as figures in Tables
5.6 and 5.7 give very high numbers when
multiplied by typical areas | Values are still high (per property) and may
over-estimate damages - Hotel (511) gives lower
values, but pub, café all are much higher | | | | |
Damage to stock in commercial properties | Multi-Coloured Manual | Based on values per property, using High
Street Shop (211), with typical area of 550m2,
DDBasic depth-damage data LOW: mean depth of 0.2m MID: mean depth of 0.4m HIGH: mean depth of 0.5m | £21,841 | £68,557 | £121,234 | Used High Street Shop as figures in Tables
5.6 and 5.7 give very high numbers when
multiplied by typical areas | Values are still high (per property) and may
over-estimate damages - Hotel (511) gives lower
values, but pub, café all are much higher | | | | |
Clean-up costs | Multi-Coloured Manual | Per property, irrespective of flood
duration, house type, age and social class of
residents LOW: average clean-up costs taken from Table
4.4 for flood depths below 0.1m MID: taken as average of low and high
costs HIGH: average clean-up costs taken from
Table 4.4 for flood depths above 0.1m | £5,725 | £7,855 | £9,985 | Bungalows and ground floor flats may have
higher clean-up costs. | Includes costs of dehumidifiers (should not
be included in indirect costs) | | | | |
Erosion of assets (including land) | Multi-Coloured Manual Land values taken from
Nix (2004) | Prices are per hectare multiplied by 0.45 to
remove effect of subsidies LOW: Based on per ha price of land in
NE MID: Based on per ha price of land in
Yorkshire and Humber HIGH: Based on per ha price of land in
NW | £1,802 | £2,538 | £2,915 | Land prices refer to areas in England | | | | | |
Change in agricultural output | Multi-Coloured Manual | Prices are per hectare for the economic
gross margin for extensive grass LOW: Very bad drainage MID: Bad drainage HIGH: Good drainage | £109 | £134 | £155 | | Prices are 2001 values | extensive grass | | | |
| Multi-Coloured Manual | Prices are per hectare for the economic
gross margin for intensive grass LOW: Very bad drainage MID: Bad drainage HIGH: Good drainage | £209 | £266 | £328 | | Prices are 2001 values | intensive grass | | | |
| Multi-Coloured Manual | Prices are per hectare for the economic
gross margin for grass/cereal rotation LOW: Very bad drainage MID: Bad drainage HIGH: Good drainage | £173 | £266 | £341 | | Prices are 2001 values | grass/cereal rotation | | | |
| Multi-Coloured Manual | Prices are per hectare for the economic
gross margin for all arable: LOW: Very bad drainage MID: Bad drainage HIGH: Good drainage | £136 | £259 | £341 | Prices for all cereal, extensive and
intensive arable are very similar, combined for
ease of use | Prices are 2001 values | all arable | | | |
Impact on environmental sites | Environmental Stewardship Scheme | Based on per ha payments: LOW: Entry level stewardship for Less
Favoured Area MID: Entry Level HIGH: Organic Entry Level | £15 | £30 | £60 | No data for other levels,
e.g. higher level | Seem low compared with
ESA payments?? | | | | |
Worry about future flooding | Defra methodology | Applies to residential properties (per
property discounted over 100 years (to change,
alter cell I13)) LOW: 1 in 100 year standard of defence MID: 1 in 50 year standard of defence HIGH: 1 in 10 year standard of defence | £716 | £4,351 | £6,297 | | | 99 | years | 28.62336529 | |
Damage to historic buildings | Replacement costs (building cost
database) | Based on costs of repairing walls,
replastering, etc. LOW: £80/m2 of wall area MID: £100/m2 of wall area HIGH: £120/m2 of wall area | £80 | £100 | £120 | Based on 'normal' building costs rather than
historic building specific | 2001 prices; seem low and may be difficult
to get m2 of wall affected!! | | | | |
Damage to physical and/or mental health,
death or injury | HM Treasury (2004): Managing
Risks to the Public: Appraisal Guidance, Draft
for Consultation, October 2004 | Based on Table 5.2, source: Highways
Economics Note No. 1, 2002 - SLIGHT injury LOW: medical and ambulance costs only MID: medical and human costs only HIGH: medical, human costs and lost
output | £740 | £9,080 | £10,830 | | 2002 values | | | | |
Damage to physical and/or mental health,
death or injury | HM Treasury (2004): Managing
Risks to the Public: Appraisal Guidance, Draft
for Consultation, October 2004 | Based on Table 5.2, source: Highways
Economics Note No. 1, 2002 - SERIOUS injury LOW: medical and ambulance costs only MID: medical and human costs only HIGH: medical, human costs and lost
output | £10,030 | £123,900 | £140,450 | | 2002 values | | | | |
Permanent evacuation of area | Market price costs from National Statistics,
Survey of Mortgage Lenders, 2001 | Based on average dwelling prices: LOW: terraced house in Scotland MID: average (all dwellings) in Scotland HIGH: detached house in Scotland | £58,190 | £73,570 | £121,705 | | 2001 prices | | | | |
Disruption to household due to flood
damage | Based on rented accommodation costs. Source:
CORE Annual Digest
2002/03 | Based on average weekly rent (all
regions): LOW: 1 bedroom property MID: 2 bedroom property HIGH: 3 bedroom property | £51 | £60 | £68 | All regions does not include Scotland | Rents seem low? | | | | |
Evacuation costs and emergency services
costs | Multi-Coloured Manual | Based on 10.7% of residential property
damages (from above), per property | £2,393 | £2,817 | £2,939 | Applies to residential properties only | | | | | |
Emergency repair and response costs | Based on actual costs in Wales from Oct/Nov
200 floods | Based on costs of emergency repair: LOW: £50,000 MID: £100,000 HIGH: £150,000 | £50,000 | £100,000 | £150,000 | Based on data for Wales | 2000 prices | | | | |
Loss of utility services | Cost of providing alternatives? | | | | | | | | | | |
Loss of income/earnings | Working days lost; source: National
Statistics - Survey of Personal Incomes, Inland
Revenue | Based on average income from Scotland (per
day): LOW: for females: £14,100 per year over 225
working days per year MID: mean of males/females HIGH: for males: £21,400 per year over 225
working days per year | £63 | £79 | £95 | | 2000/2001 | | | | |
Loss of leisure and recreational
opportunities | Multi-Coloured Manual | | | | | | | | | | |
Increased travel costs: road traffic
disruption | DETR (2000) in
Multi-Coloured Manual | Based on costs per non-
PSV vehicles (
e.g. car,
LGV,
OGV) travelling at different
speeds (can take diversion length at same
speed, or change in speed) LOW: 20 kph (12 mph) MID: 50 kph (31 mph) HIGH: 100 kph (62 mph) | £0.13 | £0.22 | £0.50 | Based on
DETR (2000) | Need length of diversion (then are assuming
that travel speeds are the same) | | | | |
| | Based on costs for
PSV (per
PSV) travelling at different
speeds (can take diversion length at same
speed, or change in speed) LOW: 20 kph (12 mph) MID: 50 kph (31 mph) HIGH: 100 kph (62 mph) | £0.84 | £1.50 | £3.46 | Based on
DETR (2000) | Need length of diversion (then are assuming
that travel speeds are the same) | | | | |
Increased travel costs: rail disruption | Halcrow (2000): Costs of Substitute Bus
Services | LOW: Based on 800km/day bus services MID: Based on provision of emergency
800km/day bus services HIGH: Based on provision of 1200km/day bus
services, visiting three intermediate
stations | £480 | £600 | £805 | 2000 prices, focused on
SE of England | Doesn't take into account costs of time
delays, etc. | | | | |
Increased cost of shopping and recreational
opportunities | Increase in time and travel costs (
MCM) | | | | | | | | | | |
Cost of repairs to roads | | LOW/MID/HIGH: £2000/m based on average cost
of repairing roads of £2,000,000 pr km | £2,000 | £2,000 | £2,000 | Based on
JA assumptions | | | | | |
Costs from failure of guide level bathing
water standards | Eftec (2002) | LOW: Small beach (rural beach with few
facilities) MID/HIGH: Small resort (beach with some
resort facilities) | £48,000 | £96,000 | £96,000 | 2001 prices, based on England &
Wales | Relates to a 2.3% reduction in risk of
catching gastroenteritis. It is assumed that
this is equivalent to a 2.3% increased risk
(move from mandatory standards to guide
values). Is a per year value, hence, relates to
failure for one whole year | | | | |