The population of Manhattan below Chambers Street has more than doubled since the terrorist attacks of September 11, 2001, according to a survey released yesterday by the Alliance for Downtown New York.

Before the attacks, the area's population was 25,000 and it is now estimated at 55,000, the report maintained, adding that it has grown 14 percent in the last three years.

About 88 percent of the residents surveyed plan to remain Downtown for at least three more years, the study found, compared to 82 percent in 2007 and 77 percent in 2004.

Many of the people who moved to Lower Manhattan as renters have stayed and purchased a home, it continued, noting that "the incidence of homeownership in Lower Manhattan is increasing, with 47 percent of survey respondents indicating they were homeowners, up from 40 percent in 2007."

Nearly two-thirds have lived in the area for five or more years and "87 percent of survey respondents said that the area's overall quality of life was a key reason for choosing to live in Lower Manhattan; trailed by 84 percent who cited the quality of their apartment; 82 percent, access to mass transit; and 81 percent, area safety."

"This survey highlights the increasing numbers of individuals and families who have put down roots and built a home in our dynamic, 24/7 community - and I'm one of them," said Elizabeth H. Berger, President of the Downtown Alliance.

The survey said that "two-thirds of renters" expressed "an interest in buying a home Downtown" and "Lower Manhattan is home to more couples and households with children than singles and roommates," adding that "about 23 percent of households Downtown have children under the age of 18."

The report said that the number of Lower Manhattan households with children "likely will continue to rise as 40 percent of households without children responded that they were likely to have children in the next three years."

The area's population is affluent and well-education: the report indicated that "85 percent have a college degree, and 42 percent have done post-graduate work, compared with 39 percent of residents city-wide and 57 percent in Manhattan who have college degrees." The average and median household incomes in the area, the study said, are very high at $188,000 and $143,000 respectively.

PKS Research Partners conducted the residential survey in the fall of 2009 in three phases: a quantitative questionnaire was sent to 6,000 randomly selected residents of Lower Manhattan, achieving a 13 percent response rate; focus groups were held with residents; and, interviews were conducted with residential brokers.