Poor planning, insufficient quality control and lack of input from senior staff are to blame for the "floodgate" debacle in Hamilton, a review has found.
Hamilton Mayor Julie Hardaker ordered chief executive Barry Harris to carry out the urgent review into why thousands of letters were sent to residents incorrectly saying their homes were at risk of flooding.
City councillors were forced to call a halt to the $121,610 district plan review process because of the huge public backlash.
Mayor Hardaker has received the review and said it showed the process was lacking.
"The letters went out without sufficient and quality control - so that was a staff management issue and the right checks and balances weren't in place at the time those letters went out and they should have been."