The final phase of a project aimed at improving fish migration along the River Almond is set to get underway, after plans for changes to a historic Edinburgh weir were approved.
Councillors on the culture and communities committee were told that without investment in Dowies Mill Weir in Crammond, a "great majority" of the river will remain "largely inaccessible to migratory fish".
Salmonid, sea trout and salmon migrating through the Almond are said have been obstructed by seven local authority weirs in "very poor condition" in recent years, with Dowies Mill set to be the last to undergo alterations as part of the Almond Barriers Project.
READ MORE: Edinburgh slavery review chair says 'no evidence' in bid to remove Dundas plaque
"If Dowie’s Mill Weir were to fail, this could potentially put the upstream riverbanks, gas main, sewer, and Cramond Brig at serious risk of erosion and damage," a report to councillors said.
"The weir is in a noticeably poor state of repair and would appear likely to further degrade in the future. This is likely to alter passability for fish in unpredictable ways and be a risk to the long-term success of future improvement works unless action is taken."
After investigating, officials found that completely removing the barrier, which dates back to the 1600s and sits 180m downstream from the A-listed Crammond Brig, would be the best option to aid fish migration. However, this solution was opposed by the local community and proposals were drawn up to create a 'rock ramp' instead.
In order to "enhance the historic fabric," a roughened slope will be constructed on the downstream side of the weir to create the rock ramp fishway.
The estimated cost of the project is between £900k and £1.6m, and speaking at the committee Lib Dem Hal Oser raised the issue of maintenance costs for the new ramp.
"I'm a little nervous that there's no understanding of how much maintenance costs would be for this, it could place quite a large burden on the city," Cllr Osler said.
Council environment officer Steven Cuthill said in the medium term removal of sediment could be required, costing "probably cost a few thousands pounds to do on occasion".
He added monitoring at other local weirs where changes to enhance fish migratory conditions have been completed found some debris including shopping trolleys had been collected
"None of these have actually caused any blockage of the low flow channels and as a result hasn't required maintenance, intervention, other than having to remove trolleys and such like," Mr Curhill said.
"We've got an ageing structure at the moment that will need quite substantial investment if it was to remain in its current format."
READ NEXT:
Edinburgh swingers club investigated by council over lack of planning permission
- Edinburgh health bosses brace for winter covid wave as people urged to get vaccinated
- Edinburgh pupils blocked from YouTube after 'concerning material' accessed
Edinburgh Council give update on closure of Filmhouse and end of Film Festival
- Edinburgh whistleblowers call for public inquiry into Scottish child protection
