The government commissioned the report following floods in southern Alberta in 2005 that killed three people and caused more than $400 million in damages.
Municipal Affairs Minister Doug Griffiths said he isn't sure why the report was not released earlier and said the government is now sorting out how many of its 18 recommendations have been acted on.
"I wish I knew. I don't know why the report wasn't released," Griffiths said Friday. He was appointed minister eight months ago.
"We have to compile a list to see how far we have come along. I am not even sure if $300 million is an accurate figure anymore."
Griffiths said the figure could even be higher now, especially after the heavy rains that have soaked the province this year and last year.
The report was submitted to the government in November 2006, just weeks after former premier Ralph Klein announced his plan to resign after 14 years in office.
Klein's resignation sparked a hard-fought leadership campaign to succeed him that saw Ed Stelmach become premier in December following a run-off vote.
Other controversial recommendations in the report call on the government to stop selling Crown land in flood zones and to stop making disaster relief payments for new developments built in high-risk areas.
The report points out that 36 communities in Alberta require flood-risk assessments.
Other recommendations include having Alberta Environment designate flood risk areas and requiring people selling property in flood-prone zones to disclose the information to buyers.
Griffiths said some of the recommendations aren't workable and others would involve complex funding arrangements with the federal government and municipalities.
He said when a disaster takes place in Alberta, the province picks up the immediate costs, but anything over a certain amount is cost-shared, with the federal government paying up to 90 per cent of the bill.
He said Alberta and Ottawa agree it makes more sense to prevent and mitigate floods than to pay for damage and clean up after the fact.
Government payments for disaster claims for the 2005 Alberta floods topped $160 million.
Griffiths said some progress has been made on some of the report's recommendations and pledged that all of the flood mitigation projects would be completed, but no one is quite sure when.
"Eventually we are going to do them all. They need to be done," he said.
"There hasn't been one focused co-ordinated strategy. We are working on the inventory now to see what we have completed so far and what more needs to be done."
Wildrose Party Leader Danielle Smith said it's a "shame" that Albertans had to wait almost six years to see the report.
“There’s no telling how much damage and distress could have been avoided over the course of the last six flood seasons had this report been released and its recommendations implemented in a timely manner.”
Smith said the report’s 18 recommendations appear reasonable and cost-effective, but the government blundered its handling of the report.
“I see no apparent reason why it was withheld from the public until now,” she said.
“However, by sitting on the report for so long, the PC government may have even missed an opportunity to apply for federal stimulus dollars towards implementing the report. That drives up the cost to taxpayers to act on recommendations."
Smith said her party will press the Tory government to give a plan on how it will protect flood-prone communities.