Jim Watson was testifying at a public inquiry looking into whether it was warranted for Canada to invoke emergency powers to end the protests.
The so-called Freedom Convoy protests began at the end of January and gridlocked Ottawa for three weeks.
Prime Minister Justin Trudeau invoked the Emergencies Act on 14 February.
The Public Order Emergency Commission began six weeks of hearings last week to examine the Trudeau government’s decision to invoke the federal act, the circumstances that led to that declaration, and the measures put in place by Ottawa to clear the anti-vaccine mandate and anti-government protests.
Invoking the law requires that a formal inquiry be held.
The hearings have given a behind-the-scenes look at the confusion and frustration between the municipal, provincial and federal governments as well as local police as they sought a solution to end the protests.
In his testimony, Ottawa’s Mayor Watson said his city had “lost control” of the protest site and that Ottawa police were outnumbered.
At the time, Mr Watson had called Mr Trudeau and the federal ministers of public safety and emergency preparedness to ask for help.
“Show me the Mounties,” Mr Watson said, according to a call transcript, requesting more Royal Canadian Mounted Police on the ground to help control the protests.
Last week the inquiry heard from two Ottawa residents who detailed “extensive” effects of living in the city during the three-week protest, including the constant noise of idling trucks and honks that interrupted sleep, harassment over face masks and the loss of city services because of the gridlock.
It has also heard that police and city officials were warned early on by a local hotel group that protesters were planning an extended stay. Demonstrators made inquiries about booking hotel rooms for 30 days or more and had suggested they planned to block access to the city.
City officials and police, however, thought protesters would leave after the first weekend.
The “Freedom Convoy” arrived in the city on 28 January and was cleared by police over the weekend of 18 February.
It gridlocked much of Ottawa’s city centre with hundreds of heavy trucks at the time – a protest deemed an illegal blockade by police and the federal government – while smaller, shorter-lived protests blocked two key US-Canada border crossings.
The Trudeau government has insisted that the use of the Emergencies Act – for the first time since it became law in 1988 – was a necessary “last resort” to deal with unprecedented protests.
In his testimony, Mr Watson said he believed the city needed the law or else it “would have been at a stalemate for several more weeks”.
The inquiry is expected to hear from some 65 witnesses over the coming weeks, including Mr Trudeau.
A final report on the findings will be released early next year.