At 6 October 2020 meeting, Matters Arising from 1 September included comments by a group of residents regarding the flood defence scheme.
Over 20 householders, whose properties adjoin The Water of Leith downstream of The Railway Viaduct at Pansy Walk, asked that their observations be raised with the City Council. Moreover, they said a more general level of support for their views was held in their local area.
In summary, their views and the response of the City Council are as follows:
RESIDENTS: Since the Phase 2 works, higher water levels disproportionately affect the lowered residents'-side bank (opposite the Murrayfield Stadium back pitches-side bank), in terms of water elevation and bank erosion, which further increases flood risk where trees are undermined.
COUNCIL: The erosion on the residents'-side bank is caused by people accessing the water's edge. Scouring and undermining of tree roots will be considered as part of the annual watercourse inspections.
RESIDENTS: Baird Drive and the Saughtonhall estate are at risk of major flooding whenever the residents'-side bank is affected by higher water levels, which condition the Phase 2 works have made more likely. Even before the works, this condition was associated with 3 major floods and 3 'near misses' in the last 35 years.
COUNCIL: The flood scheme offers protection from river flooding up to the 1:200 return period. (Following meetings with residents and to provide reassurance, the trigger for closing the Baird Drive floodgate has been lowered and a new level sensor at the bridge with an alarm in place for when to close the gate).
RESIDENTS: The lowering of the residents'-side river bank, while retaining or building-up the Murrayfield Stadium-side bank, was a late decision and not in the original design. The lower bank height results in excess water disproportionately diverting along Pansy Walk to the, also lower, Baird Drive floodgate.
COUNCIL: This is as designed, including the flooding of the Pansy Walk footpath at high water levels.
RESIDENTS: The Baird Drive floodgates, which were designed for a reasonable level of flood risk, are higher than residential boundary walls upstream and flood walls protecting residential areas downstream.
COUNCIL: The floodgate is slightly lower than the walls (which have coping stones).
RESIDENTS: Residents request the reinstatement of the residents'-side river bank, the removal of which takes no account of the course of the river upstream, and which was not in the original designs, and which results in disproportionate deflection of high level flows to lower-level defences on the residents' side, rather than under the Baird Drive bridge.
COUNCIL: The course of the river has not been altered by the development of the flood scheme, with the base of the river banks still being the same as before construction. The scheme has been designed to accommodate the high flows from a 1:200 event. The modelling does take account of upstream topography.
RESIDENTS: Residents have a better visual understanding of the situation than remote flood teams, who appear never to have closed both sets of floodgates at the same time.
COUNCIL: The Council has multiple telemetry systems and has also acted in anticipation of predicted flows before telemetry and alarms are triggered. Both floodgates are only required in cases of very high anticipated flows.
For more about the Flood Prevention scheme from this website, type flood into the search box at the top of this page.
Image credit: A 2008 drawing from Phase 2 scheme planning application, (c) City of Edinburgh Council / Arup