Appendix 1 - Short Listed Options
Perth and Kinross Council · 27 November 2023
Back to Climate Change and Sustainability Committee — 27 November 2023 and its agenda
Text extracted from the council's PDF. Layout and reading order may differ from the original.
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Appendix 1 - Short-listed Options Option Description Progress to Modelling? Progress to Further Evaluation? Capital Cost (£M) Benefit/Cost Ratio (BCR) 1 Upstream flood storage and natural flood management south of M90 Yes Yes Not fully costed as required land take (10% of upper catchment) to achieve benefit would take BCR significantly below 1. 2 Improve drainage on M90 and Broxden area Ruled out prior to modelling as no data available from Trunk Road operator. To be investigated further as part of the Perth Surface Water Management Plan. 3 Increase flood storage at existing Perth Flood Scheme ‘wet’ ponds, Glasgow Road Yes Yes £0.47M 0.66 4 Increase flood storage at existing Perth Flood Scheme ‘dry’ pond, Glasgow Road Yes Ruled out due to increased flood risk in more frequent flood events (1 in 5-year and 1 in 10-year floods) 5 Culvert upsizing and flood storage area, Necessity Brae (Cherrybank) Yes Ruled out as only provides limited localised benefit at high cost 6 Culvert upgrade, Buckie Brae Ruled out prior to modelling – would increase flood risk; main issue is blockage, not capacity 7 Channel modification (dredging) Buckie Braes to South Inch Yes Yes £0.21M 1.0 (was found to be of limited benefit; additional costs for culvert upgrades and bank stabilisation would reduce BCR well below 1.0) 8 Flood storage area, Low Road to Orchard Place Yes Yes £0.55M 0.60 9 New flood defences, Orchard Place Yes Ruled out due to limited benefit
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10 Improve culvert capacity, Queen’s Avenue Yes Yes £0.27M 1.39 11 Improve culvert capacity, Queens Avenue and modify adjacent river channel Yes Yes £0.31M 1.42 12 New flood defences, Croft Park & improve Craigie Burn to South Inch reservoir spill mechanism Yes Ruled out due to high cost and increased flood risk from reservoir in extreme flood events 13 Improve Craigie Burn to South Inch reservoir spill mechanism Yes Yes £0.31M 0.88 14 Options 11+13 combined Yes Yes £0.62M 1.0 (not considered a robust enough economic case at this stage).
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Location Plan of Short-Listed Actions