Last week, as a supplement to all 15 newspapers in the state, virtually every Alaskan received a 28-page, tabloid-size, full-color brochure, offering a brand new state capital - beautiful, livable, energy-efficient, ecologically sound and easily accessible.

If the legislature approves, the voters of Alaska will buy or reject the project in a bond authorization referendum next November. The total cost to get the new capital city built and functioning by 1994 is about $3.5 billion, taking inflation into account. Alaska's taxpayers would invest about one-third of this amount.

Alaskans voted in 1974 to move their capital from Juneau, which is 600 miles from Anchorage and accessible only by air for a $200 round-trip ticket.

Alaskans voted again in November 1976 to choose the site, near Willow, in the Matanaskua-Susitna Valley, 70 miles north of Anchorage, the largest city in the state.

The natural beauty of the site is breathtaking. The city, as planned by a special commission, would be built amidst rolling farmlands and wilderness, covered with spruce, willow and birch, dotted with small lakes and bogs, and framed by rugged mountain ranges, dominated by the distant majesty of Mount McKinley.

The site is in the path of Alaska's inevitable urbanization, so that building the planned city with its ecological safeguards would, in effect, save this beauty from the ruin of urban sprawl.

The planners would consolidate the small lakes and bogs into three large lakes and build the city between them. To serve the state government and all the support that requires, the capital requires a population of 37,000. These people would have complete freedom of choice how to live. Some Some would live in downtown apartments and townhouses, others would live in "urban villages," in various types of housing, including mobile homes.

Under the plan, the government buildings would be tightly interwoven with business, cultural and recreation structures into bustling downtown that includes a theater, department stores, a hotel, high school and university.

One might call it "a convertible downtown," because shopping malls, plazas and walkways are largely roofed and enclosed by glass walls in Alaska's bitter winter. In summer the walls opened up.

The planners were asked "to make the city look Alaskan." Their answer is to bring Alaska into the city. There are trees and views everywhere. As in a summer resort the important buildings are oriented to look out on the mountains and the walkways are along lakefronts. As in a winter resort, shops and other attractions are on the sunny side of the street. There is always some recreation in sight - outdoor and indoor ice skating, swimming, tennis and other games.

The four residential villages, each clustered around a junior high school that also serves as social center, are designed to foster a sense of community. Each village would have a shopping center, a church or two, playfield, repair shops and the facilities needed to allow people of all ages and incomes to live together.

The villages consist of several neighborhood clusters, each with its elementary school and neighborhood store around the corner.

The city is laid out to make the private automobiles a luxury, rather than a necessity. You can get conveniently around in small buses, running on their own busways, with frequent, shetltered stops. Most residents live within 1,000 feet of a bus stop. The limited arterial auto roads don't come in conflict with human activities and have few intersections. Cars, therefore, move at relatively high speeds.

The entire city is served by one central heating plant which also supplies electric power. All utilities, including advanced sewage and solid waste disposal, will be consolidated in common corridors.

The city would be built by a Alaska Capital City Development Corporation endowed with considerable state powers but working in full partnership with private contractors. The corporation is designed to self-destruct. It would gradually hand the city over to home rule as the citizens get settled. The corporation would, however, assure continued government oversight and review on matters involving the public interest.

What all this adds up to is an extraodinarily expeditious and thorough effort to distill the highest state of the art of town planning and apply it to Alaska's needs. It is not, as so often, only an architectiural, a visual plan, but gives social and economic and environmental planning equal weight.

This remarkable job was done by a small staff, headed by Morton Hoppenfeld, the chief designer of Columbia, Md., and a host of specialized consultants.

Once the commission had its data together, it heard the ideas of five architecture and planning teams and selected the development plan of a San Francisco team (Bull, Field, Volkmann & Stockwell and Sedway-Cooke) as the basis for further design work. The final drawings bear a strong resemblance to Columbia, which is now 10 years old and clearly a success.

Alaska's capital city is conceived the way we should have conceived all the abortive new towns that went sour during the Nixon years. It is based directly on the much misunderstood "garden city" idea Ebenezer Howard first proposed 80 years ago in England - the idea of "social cities" designed to place people and nature in harmony.

But it is not at all certain that this new capital city will be built.

The new capital brochure states clearly that Juneau would be hard hit by the capital relocation. Indemnity payments would be high - and what could they buy to fill empty office buildings, homes and businesses?

It would help to move only part of the state government to the new city to soften the impact on Juneau. But would that not also weaken the proposed new city and incur additional expense?

All this is now being hotly debated discussions seem to center on cost in the Alaska legislature. Most of the rather than the new capital project's clear benefits.

But even if cost and politics defeat or compromise the plan, it is bound to have a beneficial influence on future community planning.