After three years of exhaustive discussion and analysis on a wide range of issues from nitrogen loading in coastal ponds to traffic backups at key intersections, the Island Plan is ready for public release.

A draft version of the final plan will be released by the Martha’s Vineyard Commission this morning.

An ambitious and far-reaching initiative by the commission seeking to chart the Island’s course over the coming decades, it is the most comprehensive planning document ever drafted for the Vineyard. It was created with the assistance of dozens of steering committee members and public testimony gathered at dozens of informational meetings.

The draft plan is posted on the commission Web site (mvcommission.org).

The plan will also be the subject of a series of open houses at the commission offices at the Olde Stone Building on New York avenue in Oak Bluffs.

Architects of the plan were broken into several groups, each of which has focused on specific planning concerns that include water resources, housing, natural environment, livelihood, commerce, energy, waste, growth and development.

Commission executive director Mark London said the plan looks at the Vineyard now — recording things like water quality, the number of houses and open space — while also charting a course to sustain the Island environment, character and quality of life.

“This looks at where the Vineyard is today, and looks ahead to where we are going. We can use it to see if we need to make adjustments to our current course and wind up where we want to wind up,” he said yesterday.

Several hundred pages in length, the draft plan is broken into eleven sections. The introduction notes that despite rapid development in recent years, the Island has seen many success stories.

The distinct character of each town has been retained, and small business has continued to thrive in the healthy absence of big box stores and chains, the plan concludes. The Island has a strong public transportation system in the Vineyard Transit Authority, and the community remains diverse with seasonal and year-round residents, a wide range of income levels and a variety of ethnic groups.

But there remain real challenges and problems, the plan finds. The introduction bluntly concludes that growth on the Island is unsustainable at the current rate; the population has increased from 6,034 in 1970 to 15,444 today.

“The amount of development cannot be sustained, because this growth is the fundamental cause of many of our other challenges . . . such as traffic congestion and pollution in our ponds . . . since the Island is of limited size, we have to face the fact that we simply cannot grow indefinitely,” the plan says.

Character and scenic vistas are also deteriorating, the plan finds, largely because of incremental growth that often goes unnoticed. “Many small changes — a large new house here, a roadside stockade fence there — continue to undermine this character.”

The plan also finds that suburban sprawl is consuming the countryside, as development fragments habitat and forces residents to drive to work, the store or school. Meanwhile increasing traffic is making it harder to get around, and some Island roads are at capacity.

“We are nearing a threshold where we could see serious gridlock for much of the year,” Mr. London said, adding: “It gets to the point where adding 20 per cent more cars does more than just increase traffic by 20 per cent . . . the more cars and traffic, the more exponential the problem is.”

The plan reports that wastewater is polluting coastal ponds, and energy will be more expensive and scarce in the coming years. “We are especially vulnerable to rising energy costs, since the Vineyard is inherently energy-inefficient, mainly because our detached, single-family houses are hard to heat and our spread-out settlement makes us car dependent,” the report says.

The plan offers a bleak long-term forecast for the Vineyard economy, noting that an estimated two-thirds of spending by year-round residents takes place off-Island. And while the strength of the local economy remains in locally owned businesses, these same businesses face competition from the Internet and big box stores.

Fishing and farming are threatened occupations; the cost of living is 57 per cent higher than the national average and there is an acute lack of affordable housing.

There is a constructive element too; the plan offers recommendations for improving the quality of life on the Vineyard in the coming years, such as restoring the health of salt ponds and bays by rebuilding eelgrass beds to support shellfish and sustaining the year-round community by addressing the affordable housing problem. It also recommends a move back to compact, mixed-used, walkable town and village centers.

“An important and exciting principle of the Island Plan is that we cannot only ensure that future development better responds to community needs, but we can repair many errors of the past, such as by bringing polluted coastal ponds back to health, by restoring fragmented habitat and by reestablishing scenic beauty,” the report states.

Open houses on the draft Island Plan are set for the following dates at the Martha’s Vineyard Commission office in the Olde Stone Building on New York avenue in Oak Bluffs: August 26 from 4 to 7 p.m.; August 29 from 10 a.m. to 1 p.m., and August 31 from noon to 3 p.m.