Combining results

The results in the previous paragraphs have been combined to give an insight into the rough costs estimations of self-reliance. A distinction has been made in costs of continuation of compartment 1 including the unembanked areas, and fast recovery in compartment 2 and 3. Furthermore an insight is given in the flood proofing costs of environmental risk hotspots.

4.4.1 Cost of continuation in compartment 1 and unembanked areas

At this stage it is possible to give an insight in costs for continuing operation of infrastructures during different flood events, with flood proofing achieved by different types of measures. A distinction has been made between the different types of infrastructures to provide a clear view on how total costs are composed for each infrastructure.

In each of the following tables flood proofing costs for minimum and maximum flood depth is shown based on the map in appendix 1. These costs are divided in levels of criticality at which hotspots function, in the same manner as is introduced in the frameworks in paragraph 4.3. Each table is based on a different type of focus measures and shows combinations flood height for minimum and maximum flood depths. Focus means the cheapest measure in the mentioned type is chosen; if no measure of this type is present, the overall cheapest measure is chosen. This focus therefore does not rule out use of a different type of measure but gives priority to the mentioned type of measure. In table 7 a focus on temporary measures is shown. Temporary measures are also the lowest cost measures; this table therefore simultaneously shows the lowest cost measures. The measures covered are: sandbags, container/gabion, geotech tube, tube, flexible free-standing and flexible frame. Temporary measures will be put in place only shortly before a flood occurs.

Table 7 – Flood proofing costs for infrastructural hotspots, focus on temporary measures

Flood proofing costs Focus: temporary measures (=lowest possible cost)

Flood depth min max min max min max min max min max

Criticality level 1 € 18 € 442 € 0 € 0 € 0 € 0 x x € 0 € 31 Criticality level 2 ? ? € 0 € 4 € 0 € 0 € 20 € 429 ? ? Criticality level 3 ? ? € 0 € 1 € 0 € 0 ? ? - - Criticality level 4 - - ? ? - - - - Total € 18 € 442 € 0 € 5 € 0 € 0 € 20 € 429 € 0 € 31 Electricity infrastructure Sewerage infrastructure Drinking water infrastructure Natural gas infrastructure Heat network infrastructure

€ 0: hotspots present but do not need flood proofing

x: no hotspot present on the island to be flood proofed on this level ?: hotspots not located but perhaps need flood proofing

39 An overview of semi-structural measures, which are demountable and pre-installed, is shown in table 8. These measures are structural in the sense that their application has to be facilitated by a

structural adjustment on the hotspot. They can also be seen as semi-temporary measures because human interference is always needed before a flood occurs.

Table 8 – Flood proofing costs for infrastructural hotspots, focus on semi-structural measures

Costs for structural, in this case being levee/dike, floodwall, wet proofing or dry proofing, can be found in table 9. These measures do not need human interference before a flood occurs, once they have been implemented on a hotspot.

Table 9 – Flood proofing costs for infrastructural hotspots, focus on structural measures

Flood proofing costs Focus: semi-structural measures

Flood depth min max min max min max min max min max

Criticality level 1 € 230 € 944 € 0 € 0 € 0 € 0 x x € 0 € 619 Criticality level 2 ? ? € 0 € 64 € 0 € 0 € 268 € 624 ? ? Criticality level 3 ? ? € 0 € 1 € 0 € 0 ? ? - - Criticality level 4 - - ? ? - - - - Total € 230 € 944 € 0 € 65 € 0 € 0 € 268 € 624 € 0 € 619 Electricity infrastructure Sewerage infrastructure Drinking water infrastructure Natural gas infrastructure Heat network infrastructure

Flood proofing costs Focus: structural measures

Flood depth min max min max min max min max min max

Criticality level 1 € 237 € 939 € 0 € 0 € 0 € 0 x x € 0 € 756 Criticality level 2 ? ? € 0 € 122 € 0 € 0 € 253 € 448 ? ? Criticality level 3 ? ? € 0 € 24 € 0 € 0 ? ? - - Criticality level 4 - - ? ? - - - - Total € 237 € 939 € 0 € 146 € 0 € 0 € 253 € 448 € 0 € 756 Electricity infrastructure Sewerage infrastructure Drinking water infrastructure Natural gas infrastructure Heat network infrastructure

40 4.4.2 Cost of fast-recovery

In total, five hotspots have been identified within compartments 2 and 3. To facilitate fast recovery of desired critical infrastructures in these compartments, these hotspots should be flood proofed. Table 10 shows the costs for flood proofing minimum and maximum flood depths with temporary measures. Tables 11 and 12 respectively show the same minima and maxima for semi-structural and structural measures.

Flood proofing of one water quantity hotspot, pumping station # 16, could not be calculated because no flood proofing option was available. The total amount for the maximum flood depth therefore is in grey because it does not cover for flood proofing all the hotspots.

Table 10 – Flood proofing costs for recovering hotspots in compartments 2 and 3, focus on temporary measures

Table 11 – Flood proofing costs for recovering hotspots in compartments 2 and 3, focus on semi-structural measures

Table 12 – Flood proofing costs for recovering hotspots in compartments 2 and 3, focus on structural measures

Flood proofing costs Focus: temporary measures

Flood depth min max min max min max

Total € 0 € 1 € 42 € 39 € 23 € 97

Sewerage

infrastructure Water quantity Health care

Flood proofing costs Focus: semi-structural measures

Flood depth min max min max min max

Total € 69 € 156 € 42 € 39 € 466 € 1.265

Sewerage

infrastructure Water quantity Health care

Flood proofing costs Focus: structural measures

Flood depth min max min max min max

Total € 69 € 156 € 42 € 39 € 570 € 888

Sewerage

41 4.4.3 Cost of flood proofing environmental threat hotspots

Contamination of the living environment could prevent fast recovery of flooded areas. Environmental threat hotspots have to be taken into account in order to be able to prevent this long term

contamination after an extreme flood event. Costs to do so can be found in tables 13, 14 and 15. Flood proofing costs are generally high because of the large area of the plots. Insight in necessity of flood proofing the entire plot or just parts of has not been determined. The given costs are therefore maximum values; actual costs could be lower when only parts of the areas need flood proofing.

Table 13 – Flood proofing costs for recovering environmental hotspots in compartments 2 and 3, focus on temporary measures

Table 14 – Flood proofing costs for recovering environmental hotspots in compartments 2 and 3, focus on semi-structural measures

Table 15 – Flood proofing costs for recovering environmental hotspots in compartments 2 and 3, focus on structural measures

Flood proofing costs Focus: temporary measures

Flood depth min max min max min max min max min max

Total € 0 € 11 € 0 € 7 € 9 € 25 € 40 € 294 € 55 € 154

Risk 41 Risk 44 Risk 45 Risk 46 Risk 47

Flood proofing costs Focus: semi-structural measures

Flood depth min max min max min max min max min max

Total € 0 € 220 € 0 € 140 € 115 € 260 € 529 € 1.196 € 719 € 1.625

Risk 41 Risk 44 Risk 45 Risk 46 Risk 47

Flood proofing costs Focus: structural measures

Flood depth min max min max min max min max min max

Total € 0 € 269 € 0 € 119 € 30 € 48 € 213 € 294 € 131 € 195

42