An estimated 5,681 people in Erie County were homeless at some point in 2012, an annual survey has found.

That’s about 600 more homeless people than in 2011, although the authors of the report said at least some of the increase was the result of better data collection.

“We counted people we may have missed before,” said Dale Zuchlewski, executive director of the Homeless Alliance of Western New York.

Still, the survey noted a disturbing 16 percent increase in the number of homeless families, estimated at 2,017.

And more than three-quarters of them are single mothers.

“There are just too many single moms living on the edges of homelessness and more are falling in,” Zuchlewski said. “This is a nationwide problem. It’s not unique to Buffalo.”

Family homelessness often has devastating effects on children, and it results in poor school attendance and performance, perpetuating a cycle of poverty, he added.

The survey covered Oct. 1, 2011, to Sept. 30, 2012.

It found that 540 people – up from 492 in 2011 – spent some portion of the year living on Buffalo’s streets or in cars and abandoned buildings.

The number of chronically homeless people fell by 20 to 463. The U.S. Department of Housing and Urban Development defines chronic homelessness as being without a home for one year or longer or four or more times in a three-year period.

The survey noted a bright spot: The number of homeless veterans fell to 207 from 223 in 2011. The number could decrease further thanks to a new Veterans One-Stop Center that opened recently on Main Street and more federal funding to address the issue.

But the area needs more affordable housing for people living in poverty to overcome homelessness in general, Zuchlewski said.

He pointed to the loss of 300 single units of low-income housing when the Lafayette Hotel was renovated into boutique hotel rooms and high-end apartments.

The project was a great success for downtown Buffalo, he said, “but those units were never replaced.”