You could call it the case of the Lost Lawrencians.

But whatever you call it, city leaders now believe it is a mystery that needs to be solved.

City commissioners soon will begin their own sleuthing to determine why the U.S. Census Bureau has estimated the city’s 2005 population to be 81,816 people but the city’s planning department has estimated it to be nearly 10 percent higher at 89,643 people.

“We think the population figures the Census Bureau has produced don’t reflect Lawrence’s past and don’t chart an accurate path for Lawrence’s future,” Interim City Manager David Corliss said Wednesday.

That’s the first public indication that the city may officially challenge the Census Bureau numbers, which in June showed that Lawrence in 2005 had actually declined slightly in population. If true, that would mark the first time since at least 1900 that Lawrence’s population had fallen.

The June report, though, was just the latest indication Lawrence isn’t growing as fast as it once did. For five years in a row, the Census Bureau has estimated the city’s population to be far below what city leaders have estimated. The Census Bureau has estimated that since 2000, Lawrence has had an annual growth rate of just 0.3 percent. That is significantly below the city’s historical average of about 2 percent.

City report forthcoming

Corliss said that following the latest Census report, he asked members of the city’s planning staff to begin researching how the city estimates its population and whether the Census numbers could be correct. City staff members are finishing a report of their own and are scheduled to present it at next Tuesday’s City Commission meeting.

Corliss said the city report would point to a number of factors that dispute the Census numbers. They include the fact that residential building permits have generally grown in number and that the number of utility bills sent out by the city do not suggest a decline.

Figuring out which set of numbers is correct could have significant implications. For example, the city is planning to open a new $80 million sewer treatment plant by 2010. All the city’s financial plans have called for there to be about 100,000 residents in the city by the time the plant opens.

But if the Census Bureau is correct in its estimates, the city will have only about 83,000 people when the plant comes on line. That would mean the number of households available to pay for the plant would be off by several thousand.

“That would be very significant, but we don’t think the Census Bureau is correct,” Corliss said. “I do believe we’re not growing like we grew in the ’90s, but we’re taking that into account as we plan that project, and we’re also strongly looking at increasing our economic development efforts.

“I don’t want people to think we’re just yelling at someone we disagree with. We are seriously looking at how we grow.”

Census support

Lawrence school district leaders also are studying the issue.

During the same period for which the Census reported a slowdown in Lawrence growth, the number of students in the school district also declined. On Monday, the district confirmed that trend held true for this new school year, too.

Earlier this year, the school board hired an Overland Park demographics company to provide guidance on what school leaders should expect in terms of future enrollment. That report also is near completion and is expected to be presented to school board members at their Monday meeting.

Tom Bracciano, director of facilities for the school district, said the report would recommend the district put its faith in the Census Bureau numbers.

“We’re going to use the Census report because we think they are the best numbers out there,” said Bracciano, who hasn’t yet seen the city report responding to the Census Bureau.

“My personal opinion is that the Census Bureau is right,” said Bracciano, who previously has run for the City Commission. “We just have less kids coming to Lawrence. It makes sense when you look at the price of housing and the number of available jobs that will support a family.”

Bracciano pointed to enrollment at the district’s Langston Hughes School. It is in the western-most portion of town and is designed to serve what is generally regarded as the fastest-growing area of the city. Yet the school gained only 30 students this year. Bracciano said that’s much different from when the district built Quail Run School in the mid-1980s to accommodate West Lawrence growth. It was not uncommon for that school to see increases of about 100 students per year.

Questions remain

City commissioners, who also have not yet seen the city’s analysis of the Census Bureau numbers, have been split on the accuracy of the Census population projections.

“I’m convinced that things have slowed,” City Commissioner Mike Rundle said. “I think it is a combination of cost-of-living factors. I think it has as much to do with our low income levels as it does the price of our housing.”

But City Commissioner Sue Hack said she thought there were too many signs of growth in the community for the Census Bureau numbers to be correct.

“We need to determine a method to reconcile these differences,” Hack said. “I’m not an expert in counting people, but the Census numbers don’t make sense to me.”

A key piece of information in the city’s upcoming report likely will be what the city estimates the community rental vacancy levels to be. Several landlords have said rental vacancies have increased significantly over their historical averages as more renters have become homeowners during the recent period of low mortgage rates. Low interest rates also have spurred new apartment construction.

The city has about 20,000 rental units, so a significant uptick in the vacancy rate could mean thousands of homes in the city are sitting empty. But both city leaders and landlords admit there is no good study conducted regularly to determine the city’s overall vacancy rate. The Census estimates vacancy rates once every 10 years, but that data becomes outdated quickly.

Census Bureau officials said they have not changed how they determine population estimates, which rely on a formula and use data from federal filings such as tax returns. In other words, it is the same process the bureau was using to come up with the growth rates of 2 percent that generally were accepted by city leaders during the 1980s and 1990s.