Mr McClymont said the only additional cost had been incurred by having to hire a barge to ferry a concrete breaker to the island when an unexpected concrete structure had been uncovered by the diggers and needed to be smashed up.
That had cost around $2000.
"Even then, I may have been able to risk getting the concrete breaker over by some other means, but I was a bit gun-shy by then and could just imagine having the concrete breaker stranded in the middle of the lake, begging to be rescued."
Mr McClymont said that, overall, the weather had been kind to the crew doing the work and now that it was all over he had been fielding "compliments from all over the place, especially as we seem to have created a haven for the black-billed gulls".
The island is to be replanted but the intention is to leave a portion of it in metal so the gulls can colonise it.