Perth and Kinross Council has admitted a delay in closing the North Inch floodgates last month may have led to nearby properties being damaged.
Four flood gates beside the North Inch remained open for a period of time during the heavy rainfall in October.
The authority said a full investigation was being carried out as there were existing sewer, surface water and groundwater issues in the area.
Councillors will review the handling of the flooding at a meeting on Wednesday.
The authority said 34 properties, including the Bell's Sports Centre and North Inch Bowling Club, were flooded during the weekend of 7 and 8 October.
In a new report to councillors, the authority said it acknowledged it had been "a very difficult time, particularly financially and emotionally" for those affected.
The council said its flood gate closure triggers were based on tide levels and water flow levels from the Scottish Environment Protection Agency (Sepa).
It said Sepa called at 20:14 on 7 October with information on river flow levels that indicated the closure of all gates except Tay Street, Queens Bridge and three gates at Friarton.
The council said as this was 91 minutes before high tide and the gates take 4.75 hours to close, there was not enough time or staff to do so.
As a result, it decided to monitor the water level until 06:00 the following day.
When the water levels began to rise, the council deployed staff to close the gates at Perth Harbour and Commercial Street/Bridgend Court to "focus on protecting the most vulnerable residents and business premises".
Three hours later, water was seen coming through the open gate at the War Memorial into North Inch and one of the council teams was redeployed there.
When they arrived 30 minutes later, they were unable to close the flood gate as the force of water was too strong to stand up in and padlocks were submerged.
The remaining four North Inch gates were closed by 11.40, but the force of water at the War Memorial gate remained too strong for workers to stand in.
The report states: "Four flood gates adjacent to the North Inch remained open for a period of time during the flood event.
"The council acknowledges that the delayed closure of these may have contributed to the flooding of some properties."
Sepa said previously that it began warning public partners, including Perth and Kinross Council, of potential flooding on Wednesday 4 October in its daily flood guidance statements.
It added that on Friday 6 October, a flood alert covering the region was issued - a Met Office Amber weather warning for heavy rain was already in place - and a major incident was declared by Police Scotland.
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