Assistant Chief Constable Stephen Martin said it wouldn't have taken much more for the conditions to have become more difficult.
He said the preparations in place were in no way an "overreaction" as demonstrated by the high water levels at around 12pm.
"Over the past few hours we have experienced extreme tidal surges in many coastal areas across Northern Ireland. In preparing for these types of events we must plan for the worst but thankfully, on this occasion, our defences held in most areas," he said.
"At points yesterday, we were putting in place plans to evacuate hundreds of homes in the Sydenham area, such was the extent of our concern."
According to ACC Martin, the last time the region had a similar weather event was in 1903 and he thanked those involved in the operations for their efforts and vigilance.
However, he warned that the severe weather risk remained over the next three days, particularly on Monday.
I think our response was not only vindicated, but I think we were lucky with the way the weather ameliorated over the period of the early hours of this morning.
PSNI ACC Stephen Martin
Water levels rose significantly in many areas in east Belfast but flood defences held, without major flooding.
Coastal areas in Holywood, Carrickfergus, Portaferry, Donaghadee, Newcastle, Newtownards and other parts of the east coast have experienced some flooding.
Coleraine town centre, Carnlough and the north Antrim coast have also been affected.
There are no reports of any significant damage to homes, with gales easing on Friday night.
Earlier last-minute temporary flood defences were erected by police in the Docks area of Belfast to protect the Clarendon Dock, Corporation Street and Sailortown areas.
Residents in the Sydenham and Victoria Park areas of the city were also told they were at risk of flooding, and had been advised to "move their valuables upstairs" and "pack a case" in the event of an evacuation. Thousands of sandbags were distributed, with people queuing at the Inverary Community Centre overnight and throughout the morning.
Extensive preparation work was undertaken from Thursday afternoon, with police urging the public not to remove sandbags placed at key points protecting the area.
On Friday, former Lord Mayor Gavin Robinson, of the DUP, tweeted: "Water level at Sydenham and Mersey Street was critically high, but seems to be subsiding."
The Connswater River burst its banks, flooding the entrance of Victoria Park.
The Northern Ireland Fire & Rescue Service with specialist teams and pumping appliances was deployed into areas at risk.
There was a reduced risk of flooding in the city centre area and the Victoria Square area of Belfast - the underground car park there has now reopened.
All Rathlin Island ferries were cancelled, while a spokesperson for P&O said their services may be disrupted and advised passengers not to travel unless deemed necessary. Strangford Lough ferry services have resumed.
Motorists are advised to continue to exercise caution due to the risk of fallen trees and debris, while there is a warning to stay away from coastal paths and walkways for anyone who is out and about over the weekend.
The PSNI has been co-ordinating a multi-agency planning team in anticipation of the high tides and harsh weather, which will continue until Monday.
Other coastal surges are expected on Sunday and Monday. The Met Office has also issued a yellow warning for snow on Saturday and heavy rain on Sunday across Northern Ireland.
PSNI have said a range of agencies including the Office of First Minister and deputy First Minister, Belfast City Council, NI Fire and Rescue Service, the Rivers Agency, Belfast Health Trust, Road Service, NI Water, NI Electricity, British Telecom and Translink have been working together to ensure plans are in place to deal with all eventualities.
An emergency Executive meeting chaired by Peter Robinson and Martin McGuinness was held at Stormont to review the multi-agency flooding response on Friday morning.
The Ministers said in a statement: "We are (...) very grateful for ongoing efforts of those from a variety of organisations who have been working through yesterday and last night, and who continue to work, to mitigate against potential risk."
Mr Robinson then visited flood defences at Victoria Park before high tide.
Meanwhile Met Éireann said high winds, heavy rain, high tides and localised flooding have affected coastal areas, including counties Donegal, Clare, Cork, Kerry and Limerick in the Republic of Ireland, where the River Liffey burst its banks in Dublin.
Anyone who needs to report flooding can call a flooding incident line on 0300 2000 100 or the police non-emergency line on 0845600 8000. More information is available here.