Paschali Stauroula Karanika Chrisoula Kokovinos Konstantinos Koujianos Ioannis Vatistas Panagiotis

Transcription

1 Evros River Flood Lavara Case Study Chouvardas Konstantinos (Coordinator) Papapostolou Christos Chamitidou Maria Partsias Christos Doulgeraki Chrisoula Paschali Stauroula Paschali Stauroula Karanika Chrisoula Kokovinos Konstantinos Koujianos Ioannis Vatistas Panagiotis

2 Proforma A : Data regarding the site to be assessed TASK 1. Topographic map, with the flood plain at Lavara Blue=Flood Hazard Zone Pink= Main Embankment Red=Case Study Area limits

3 Site map for a small area of the floodplain Part of the cultivated area Residential and non Residential Properties at Risk TASK 2. Detailed site map, showing locations of the urban area and individual properties at risk Evros River

4 TASK 3. Administrative authorities responsible for Flood Management. In National Level: Ministry of Environment and Energy Special Secretariat for Water. Ministry of Infrastructure, Transport and Networks Directorate of Flood Management and Land Reclamation Works. Ministry of Interior General Secretariat of Civil Protection. In Regional Level: Region of Eastern Macedonia and Thrace Regional Unit of Evros. Infrastructure authorities. Civil Protection authorities. Municipality of Soufli. Infrastructure authorities. Civil Protection authorities. Local Police and Fire Departments.

5 TASK 4. Flood risk management rules and guidelines from: Directive 2007/60/EC on the assessment and management of flood risks and its implementation in Greece (Historic Flood Incidents Database, Important Flood Incidents Database, Flood Incidents Registration Database). Handbook on good practices for flood mapping in Europe, 2007, European exchange circle on flood mapping (EXCIMAP). Flood Risk Management Plan Phase I-III. Ministry of Environment and Energy - Special Secretariat for Water And other relevant studies in the wider Case Study Area. End of Proforma A

6 Proforma B : Details about (a) the current flood risk situation and (b) the key features at risk today and in the future from flooding at the site; Flood History in the Study Area: Local District Population(2011) Numberof flood events ( ) Amorio Lavara 1, Mandra Important Flood Events ( ): Event Date Local District Damaged Area (m ) Compensation ( ) 17/05/1998 Lavara 5, , /05/2006 Amorio 2, , /05/2006 Lavara 6, , TASK 5. Flood Extent and History

7 Damages of Crops of the Lavara Area Year Area of SqrKhm Crop ,500 Cereals, Clover ,000 Cereals, Clover ,570 Cereals,Clover ,170 Cereals Cotton Sunflower Corn Clover ,170 Cereals Clover ,120 Cotton Corn Cereals, Clover ,000 Clover, Cereals

8 Lagina area flood 2010 Mandra area flood 2010 Pragi area flood 2010 Lavara area flood 2010

9 Primary sectors affected by flood events: Agriculture. Livestock. Trade and Business. Transport Infrastructure. Properties (Public and Private). No archeological sites & monuments in Case Study Area. TASK 6. Details of flood damage in the past Damaged pump station Flooded area

10 There are no human casualties recorded Bund break (caused by the water pressure) TASK 7. Details of injuries and loss of life in the past Bund break (caused by human intervention)

11 Evros River: Basin Area: 53,000 km % in Bulgaria 27.5% in Turkey 6.3% in Greece River Length: 528 km Estimated flow (annual average): 103 m 3 /s TASK 8. Flood hydrology (flows; return periods; flood extents; etc)

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13 Main causes of flooding in Case Study Area: Evros River flooding. Stormwater flooding from streams vertical to Evros River.

14 Evros River Mandra Stream

15 Flood Hazard Map by Return Period of 20 years TASK 9. Modelled or estimated flood extent for geographical areas by return period (20, 50, 100 and 1000 year floods)

16 Flood Hazard Map by Return Period of 50 years

17 Flood Hazard Map by Return Period of 100 years

18 Flood Hazard Map by Return Period of 1000 years

19 Flood Depth per Return Period alongside the Railway and National Road Embankments Return Periods(years) Flood Depths alongsidethe Railway Embankment (m) > > >2.00

20 Current Flooding Situation - Damage estimations per Return Period Damage in buildings Return Periods (years) Residential Properties Non Residential Properties TASK 10. Property numbers and types in the Task 9 areas Damage in cultivated areas Return Periods (years) Area(ha) , , ,380

21 Population affected by the flood incidents Return Periods (years) Population TASK 11. Population numbers in each of the Task 9 areas Population of Lavara: 1093 residents End of Proforma B

22 Proforma C : Overview of the impacts that is expected under the do-nothing scenario; Depth / Damage Data in Residential Properties Residential Sector d/d curve: residential Depth (cm) Damage (Euros) 1,280 7,715 10,640 13,400 14,255 14,920 15,555 16,165 17,130 Depth (cm) Damage (Euros) 18,035 18,880 20,495 21,670 22,415 23,195 24,035 24,940 Depth / Damage Data in non Residential Properties TASK 12. Undertake research into all the available depth/damage function data that might be used in the appraisal (both Residential and Non- Residential properties) etc. Non Residential Damage/m 2 of ground flood building area Depth (cm) Damage (Euros) Depth (cm) Damage (Euros) Agricultural losses Flood cost ( /ha) Horticulture Intensive Extensive Intensive Extensive arable arable grass grass 1,

23 Potential Damage in Buildings for the do-nothing scenario TASK 13. Return Periods (years) Houses at risk (No.) Non-residential properties at risk (No.) Mean depth of flooding inside properties (m) Potential Damage in agriculture for the do-nothing scenario Return Periods (years) Number of hectares flooded , , ,380 Assign likely future flood damage values (in ) to each property for each return period using whatever data is available, even approximations

24 Potential damage in Buildings for the do-nothing scenario Return Periods (years) Total Damage for Residential Properties Total Damage for non - Residential Properties 2 536, , ,777,500 6,080, ,699,000 6,960, ,018,800 11,400, ,706,600 12,480,000 Potential damage in agriculture for the do-nothing scenario Return Periods (years) Agricultural Losses 2 22, , , , ,600 Total potential damage for the do-nothing scenario TASK 14. Total the damage values for each return period areas. Return Periods (years) Total damage 2 988, ,918, ,923, ,691, ,490,200

25 RP (years) Probabilit y Damages ,918, ,923, ,691, ,490,200 Interval probability Mean damage Interval damage Cumulative annual damages Discounted AAD ,959,220 3,131,649 3,131,649 89,848, ,420, ,622 3,594, ,121, ,807, ,073 3,802, ,090, ,590, ,318 4,032, ,698,780 Total Annual Benefit: TASK 15. Tabulate the lossprobability function to calculate future annual average damages for the site as a whole (see Table C11in Annex C of the FloodCBA Guidelines for a detailed example). The result is the annual average of those damages. End of Proforma C

26 Proforma D : An assessment of the possible future changes and/or interventions that may affect the site The Lavara Case Study list of intervention scenarios: 1. Do-nothing. 2. Closing of 3 National Road and Railway underpasses (Do-minimum) 3. Enhancing of the main by-pass channel in the irrigation network 4. Enhancing of the river s main embankment TASK 16. Review all likely interventions to reduce flood risk at the site and their likely effective functional lives (i.e. when they remain effective)

27 Shortlist of proposed flood protection interventions: 1. Closing of 3 National Road and Railway underpasses (Do minimum) 2. Enhancing of the main by-pass channel in the irrigation network 3. Enhancing of the river s main embankment TASK 17. Decide on a shortlist of, say, 3-6 interventions at different costs and hence standards of protection.

28 1. Closing of 3 National Road and Railway underpasses: I. Overpass protection (2 Alternative Designs) II. Arrangement of the existing flood protection and drainage infrastructure Alternative A: Extended berms No land redistribution Construction of 3 berms Height: 4.00m Road Grade: ±7% TASK 18. Estimate the likely whole life costs of each of the above interventions (i.e. capital costs and maintenance costs), as economic costs (i.e. not including taxation elements). Costs Value ( ) Capital Costs 300,000 Maintenance Costs 300,000 Total Costs 600,000 Alternative B: Shorter berms Land redistribution - expropriations

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30 2. Closing of 3 National Road and Railway underpasses AND Enhancing of the main by-pass channel in the irrigation network Length: 12km Indicative depth: 3.00m Indicative bed width: 3.00m Indicative slope: 2:3 Costs Value ( ) Capital Costs 1,300,000 Maintenance Costs 1,300,000 Total Costs 2,600,000

31 3. Closing of 3 National Road and Railway underpasses AND Enhancing of the main by-pass channel in the irrigation network AND Enhancing of the river s main embankment Length: 16km Existing height: 3.00m Proposed height: 5.00m Proposed crest width: 6.00m Indicative slope: 2:3 Costs Value ( ) Capital Costs 2,600,000 Maintenance Costs 2,600,000 Total Costs 5,200,000 End of Proforma D

32 Proforma E : The potential of a range of flood risk prevention measures and assess their efficacy based on CBA and/or MCA methods Costs (Present Values) Closing road and rail gaps Closing road and rail gaps AND Enhanced bypass channel in floodplain Closing road and rail gaps AND Enhanced bypass channel in floodplain AND Enhanced main river embankments Capital Costs 300,000 1,300,000 2,600,000 Maintenance Costs 300,000 1,300,000 2,600,000 Total Costs 600,000 2,600,000 5,200,000 TASK 20. Discount the recurring estimated maintenance costs of each intervention, to get a full present value of the costs of each intervention.

33 Options Interventions discounted future potential losses Benefit* Likely total costs** Total cost 1. Closing road & rail gaps 684, ,014, , , Closing road and rail gaps AND Enhanced bypass channel in floodplain 3. Closing road and rail gaps AND Enhanced bypass channel in floodplain AND Enhanced main river embankments 395, ,303,535 2,600,000 3,200, ,698,780 5,200,000 8,400,000 TASK 21. Make up a table of interventions (in ascending order of cost), showing (a) the present value of all damages to be avoided and (b) the present value of all costs

34 TASK 22. Calculate the ratio of benefits to costs Options(Repeated) Benefit : Cost ratio 250,00 Benefit:cost ratios 200,00 1. Closing road and rail gaps ,00 2. Closing road and rail gaps AND Enhanced bypass channel in floodplain ,00 3. Closing road and rail gaps AND Enhanced bypass channel in floodplain AND Enhanced main river embankments ,00 0,00 1. Closing road & rail gaps 2. Closing road and rail gaps AND Enhanced bypass channel in floodplain 3. Closing road and rail gaps AND Enhanced bypass channel in floodplain AND Enhanced main river embankments

35 Current flooding situation: Discounted future potential losses: approx. 115,698,780 After Closing the 3 National Road and Railway underpasses: Total Cost: 600,000 Discounted future potential losses: approx. 684,651 Benefit: approx. 115,014,129 After Closing of 3 National Road and Railway underpasses AND Enhancing of the main by-pass channel in the irrigation network: Total Cost: 2,600,000 Discounted future potential losses: approx. 395,244 Benefit: approx. 115,303,535 After Closing of 3 National Road and Railway underpasses AND Enhancing of the main by-pass channel in the irrigation network AND Enhancing of the river s main embankment: Total Cost: 5,200,000 Discounted future potential losses: ø Benefit: approx. 115,698,780

36 Options(Repeated) Benefit minus cost Incremental BCR 1. Closing road and rail gaps TASK 23. Calculate the value of (a) benefits minus costs and (b) the incremental benefit:cost ratios 2. Closing road and rail gaps AND Enhanced bypass channel in floodplain 3. Closing road and rail gaps AND Enhanced bypass channel in floodplain AND Enhanced main river embankments , ,15 End of Proforma E

37 Proforma F : To enable conclusions to be drawn Costsand Benefits not taken into account Impact Decision changers Injury and loss of life impacts Recreation enhancements Amenity aspects TASK 24 Assess any costs and benefits that the above analysis does not take into account. Make a judgement as to how large these are likely to be: could they be decision changers. If so, consider a full MCA analysis. Ecosystems services gains or losses Wildlife changes that provide no ecosystems services

38 The 1 st intervention (Closing of 3 National Road and Railway underpasses) is by far the most efficient, economically. The 2 nd intervention (Closing of 3 National Road and Railway underpasses AND Enhancing of the main by-pass channel in the irrigation network) appear to be less economic efficient. The 3 rd intervention (Closing of 3 National Road and Railway underpasses AND Enhancing of the main by-pass channel in the irrigation network AND Enhancing of the river s main embankment) appear to be the least economic efficient. TASK 25. Draw conclusions as to the economic efficiency of each proposed intervention

39 The 1 st intervention (Closing of 3 National Road and Railway underpasses) is the most sustainable, because of the very low maintenance costs. The 2 nd intervention (Closing of 3 National Road and Railway underpasses AND Enhancing of the main by-pass channel in the irrigation network) appear to be less sustainable than the 1 st. The 3 rd intervention (Closing of 3 National Road and Railway underpasses AND Enhancing of the main by-pass channel in the irrigation network AND Enhancing of the river s main embankment) appears to be the least sustainable. TASK 26. Draw conclusions as to the sustainability of each proposed intervention

40 The 1 st intervention (Closing the 3 National Road and Railway underpasses) is proposed to be contracted for detailed design and construction immediately. However, the competent authority should proceed with the implementation of the designs for all 3 interventions, in order to develop a holistic solution for the flooding problem in the case study area. TASK 27. Make recommendations as to which intervention to pursue further with (a) public consultations etc and (b) detailed design End of Proforma F

41 Thank you for your attention.