Rhonda Zazzara prefers to do sidewalk enforcement during the daytime, when most property owners are working.

That way, the longtime Portland Public Services employee can leave the bright green notices on doors and be on her way.

“People are not always happy to see us,” Zazzara said this week as she checked out complaints the city had received about snow-covered sidewalks on Grant and Sherman streets in the Parkside neighborhood.

The record-level snow that has fallen on Portland in the last few weeks has created challenges for anyone who has had to clear snow off sidewalks. Another big storm forecast for this weekend won’t help.

Sidewalks, especially in a city like Portland, are particularly problematic, in part because not everybody knows what the expectations are, say city officials.

Portland’s Public Services Department is responsible for clearing about 100 miles of sidewalks throughout the city, mostly downtown and around schools. The rest falls to property owners, who don’t always meet their responsibilities.

That’s when Zazzara or one of her colleagues pays a visit.

According to city code, commercial property owners are required to remove snow from the sidewalks next to their properties within 12 hours after snow stops falling. Residential property owners have 24 hours to clear sidewalks in front of their houses or apartment buildings.

In years past, city workers patrolled areas intermittently, looking for violators. This winter, the Public Services Department has responded to complaints that have come in through the Fix It! Portland online portal.

As of this week, there were nearly 300 complaints about sidewalks, according to city spokeswoman Jessica Grondin, although not all of the complaints were still active.

Zazzara said her department didn’t have many opportunities to respond to complaints before the latter half of this week, simply because employees were tied up with clearing snow.

Through Friday, the city had investigated 156 violations and served 136 notices this winter. For all of last winter, the city investigated 236 complaints and served 184 violations.

Toby Alves, who owns Union Bagel on Cumberland Avenue, was among those cited this week. It was the first time that has ever happened, he said.

“It was more funny than anything,” he said. “Someone complained, which is fine, but when you look down the street, everyone else is in the same boat. There is nowhere for the snow to go.”

The city’s warning notices say property owners must clear snow from sidewalks immediately. Those who don’t can be penalized, and if the city has to send workers to clear snow, it will bill the owner. Grondin said the cost of removal typically ranges from $200 to $500. The city can also impose a civil fine, but Grondin said that hardly ever happens.

Alves said he went out immediately Wednesday to fix the problem.

“The city employee was really nice about it,” he said. “I tried to offer him a bagel, but then I thought that could be considered a bribe, so I rescinded the offer.”

But not everybody responds the way Alves did.

Zazzara said one of her employees who delivered a notice to a house on Munjoy Hill this week was met by a threatening property owner. The Public Services employee ended up calling police.

Zazzara said the standard is to clear sidewalks to a width of 4 feet, noting that some people try to get away with clearing “goat paths,” barely wide enough for a person to walk through. Four feet is wide enough for a parent and child to walk side by side, she said, and wide enough for a typical wheelchair.

Dennis Fitzgibbons, director of Alpha One in South Portland, an organization that helps people with disabilities live independently, said the last few weeks have been a struggle for many clients. Among their biggest complaints are slippery or uncleared sidewalks and people piling snow in parking spaces for the handicapped.

“People really need to do a better job of snow clearing,” he said. “I understand they need to clear the roads first, but the sidewalks are just as important.”

Fitzgibbons, who uses a wheelchair, said many sidewalks on the Portland peninsula are simply impassible. “Some are about half the width of a chair,” he said. “And if it’s a motorized chair, forget it.”

If the sidewalk isn’t clear, he’ll travel in the road, but he doesn’t like doing that.

City officials say the first priority is to clear the major roads, then move to secondary and tertiary roads. After that come the sidewalks.

“If we can dispatch sidewalks units at the same time as roads, we will,” said Eric Labelle, Portland’s assistant director of public services.

Labelle said Portland has 10 sidewalk tractors out during any snow event.

“The last couple weeks have certainly been a challenge,” he said. “One of the bigger concerns is when sidewalks get plowed back in, which we don’t always know about.”

Labelle agrees that safety is a concern.

“It’s a resource challenge. We continue to pursue every street and sidewalk we can,” he said. “Right now, it’s an issue of volume.”

Some pedestrians are taking the voluminous snow in stride. Vincent Rowe walks his daughter Ramona to Reiche Elementary School every morning and returns to pick her up in the afternoon. He’s often accompanied by Ramona’s younger sister, Mika, who is in preschool.

The school is only a few blocks from their home in the West End, Rowe said, but the last few weeks have been challenging, to say the least.

“You walk down the sidewalks and you don’t always know where it’s going to just stop and become a wall of snow,” he said.