Regional slump won’t slow rise in island population, planners project.

If Bainbridge Island keeps growing at the relatively steady rate it has experienced over the past 30 years, it will add 9,500 new residents by the year 2025, and will reach a “buildout” population of some 33,000 by the year 2030, according the estimates endorsed by the Planning Commission last week.

And while regional officials expect the rate of growth to slow, the economic travails of the aircraft and high-tech industries are expected to have a lesser effect here.

“(Slowing of growth) is a region-wide trend and may not be as significant on the Island due to the desirability of its location,” long-range planner Steve Morse said in a memorandum prepared last week for the Commission.

Morse’s estimates were prepared as part of the planning process required by the state’s Growth Management Act. The GMA requires the state’s Office of Financial Management to estimate 20-year population growth for each county, and then requires the counties to apportion that growth to their cities and unincorporated area.

Cities must revise their Comprehensive Plans to accommodate the projected growth, but the estimates are in no sense a quota – cities that achieve their projected growth sooner than expected cannot then cut off future growth by placing a moratorium on new building, for example.

The island’s current Comprehensive Plan runs through the year 2012. It projects a population in that year of 24,280, up some 3,000 from the current estimate of 21,350.

The county is currently making new population projections through 2025, and has asked each city for its estimate.

The island’s population growth has been relatively stable, Morse said.

“A review of the population growth for Bainbridge Island indicates that it has been basically linear for the last 30 years,” he said in his memorandum, rising from 8,495 in 1970 to 12,314 in 1980 (the decade with the greatest percentage increase), then to 15,846 in 1990 and 20,308 in 2000, according to the last official U.S. Census.

Using that 30-year rate of growth, Morse projects a population of roughly 22,400 in 2010, 25,100 in 2020 and 27,800 in 2030.

Using only the experience of the last 13 years, which takes out the slow-growth decade of the 1980s, Morse projected a higher rate of growth – to 24,500 in 2010, 28,800 in 2020 and 31,000 in 2025 and 33,000 in 2030.

A slower rate of growth, taking into account the projected regional economic slump, projects island populations of 22,400 in 2010, 25,100 in 2020 and 27,800 in 2030. But because the island attracts relatively few Boeing employees or Eastside high-tech workers, Morse said the slow-growth

scenario would likely not apply to the island.

He asked that the 13-year numbers and the slow-growth numbers be forwarded to the county to use in the process of allocating a population to Bainbridge for the next round of comprehensive planning, which the Planning Commission endorsed.

The City Council’s land-use committee will consider the recommendation beginning at its meeting today.

Somewhere between 2025 and 2030, Morse said, the island should achieve “buildout,” meaning the population that could be accommodated if all available land is built out under the present code, which zones much of the island for one home per two-and-one-half acres.

But the Growth Management Hearings Board declared in 1998 that the island could not, at that point, deem itself “full” and resist taking additional population.

As a city, the board said, the island must accept “urban density,” which it has deemed to be at least four homes per acre, if and when such zoning is required to accommodate the projected population growth.

Morse noted that the availability of water is considered by some to be a factor limiting the island’s ultimate population, but he said a consultant study done in 2000 calculates that enough water is available to support a population of approximately 40,000 people.

“The study has its critics, but it is the best available information the City has to work with in determining the water available for future development,” he said.