As insurance companies wait for calls from Aucklanders whose homes were flooded last night - they've released figures showing last month's flooding in Otago cost them $28 million.

The record deluge that swamped Otago between June the 2nd and 4th resulted in nearly 2000 domestic claims costing $20 million.

Another 200 commercial and small business interruption claims have added an extra $8 million to that.