Strengthening the piers and building a new bridge could have cost up to $3.3million, and the walkway for the bridge would have had to be "very high" to be sufficiently above the 100-year flood level, Vincent and Teviot Valley property and facilities officer Christina Martin told Vincent Community Board members at their meeting on Wednesday.
"It would have to go near the top of the arch [of the piers], much higher than where the bottom of the bridge used to be, and there would need to be a gradient at either end for people to access the bridge. Aesthetically, it wouldn't look right."
Ms Martin said it had been a "hard call", but members of the Alexandra Suspension Bridge Working Group, formed in 2005, had realised the findings of a report from Beca engineers and consultants meant a bridge could not be reinstated, as they had initially hoped. This was "gutting" for them, and she praised the work they had done exploring the bridge options.
Working group member Clair Higginson said group members had "tried hard" to make the project work, "but in the end we realised it just couldn't happen".
The Beca report said the "top end" estimate of strengthening the bridge piers and constructing a bridge would be $3.3million, but using the piers as a gateway rather than part of the bridge structure would have needed a "lighter touch" in strengthening.
However, two other options will now be investigated.
One is a "clip-on" to the blue road bridge, and the other is a new, stand-alone suspension bridge for cyclists and walkers.
The Central Otago Queenstown Trail Trust has been pledged $1.7million of funding to build a bridge across the Clutha River in Alexandra as part of the $26.3million project to build new cycle trails in Central Otago.
Board members adopted Ms Martin's recommendations, which were for the board to collaborate with the trail trust to ensure any clip-on to Alexandra's road bridge would be "sympathetic with the historic bridge piers".
A maintenance strategy would be developed for the piers; the board would collaborate with the Alexandra Miners' Village and Riverside Park Trust and the trail trust about the "whole river precinct landscape" from the Shaky Bridge to the boat ramp; and a viewing platform will be investigated.