The state Legislature created an agency 37 years ago to devise an urban plan for Kakaako, at that time covered with warehouses, car repair shops and various rundown structures. For the first time, the Hawaii Community Development Authority has released a comprehensive view of numerous skyscrapers projected throughout the 450 acres with build-up tied to the upcoming elevated rail and bus systems. It is both impressive and scary. The agency will need to assure an open process that resists temptations to overbuild when it comes to elements such as unprecedented tower heights, density leading to unbearable congestion, retaining valuable open space, and manageable capacity on sewage and other infrastructures.

This Kakaako process has been unusual, unlike the happenstance growth of Waikiki and downtown Honolulu. Several tall residential buildings have emerged from earlier HCDA plans but drawings accompanying the agency’s longterm plan released last week — in its draft Transit-Oriented Development (TOD) Overlay — reveals what a highly urban Kakaako could look like in the decades ahead. That includes:

» Up to three "exemplary iconic buildings" up to 700 feet tall — almost twice the existing 400-foot maximum in most of Kakaako.

» Other new "tower types" to reach up to 550 feet high, within the 450-acre district bound by Ala Moana and South King, Punchbowl and Pii­koi streets.

The HCDA in December already chose a developer for the 690 Pohukaina St. project; at that time, the proposed 800-unit workforce rental tower on state-owned land was touted to be Hawaii’s tallest building at 650 feet. And while the project still needs further approvals, it’s increasingly clear that it’s not envisioned to be the only, let alone tallest, 650-foot-plus tower in town.

With the Kapolei-Ala Moana rail line under construction and planned to pass through the heart of Kakaako with two transit stations, HCDA’s TOD overlay plan calls for an "interplay" of residential, light industrial, entertainment, a grocery store and a limited number of hotels appealing to "travelers and business professionals wishing to stay outside of Waikiki."

"Together," the plan says, "these buildings will create a skyline of views through and between towers, as well as green spaces on podiums that will enhance views down from neighboring buildings and residential areas on the slopes of Punchbowl, Makiki and Pacific Heights."

At this point, it’s commendable that a global planning view of the Kakaako district is being taken, in the interest of comprehensive and cohesive build-out.

Understandably, observers were stunned by pictorial reviews of the plan but not dismissive.

"Wow!" said Bob Loy of The Outdoor Circle, who expressed concern about allowing towers beyond the tallest existing buildings on Oahu.

It will fall on HCDA — and the public — to ensure that exceptions or overreaches beyond existing development rules are wholly justified with community benefits, and not developer giveaways.

HCDA rules, for example, allow for land-use exemptions in exchange for more affordable housing units.

Robert Harris, director of the Sierra Club of Hawaii, said his organization wants to "watch very closely" to determine if several green design concepts, including networked bicycle lanes and open public areas, are included.

The Sierra Club is "open to the concept" of the building plans, preferring urban development rather than loss of prime agricultural land on the island.

Indeed, HCDA promises "green spaces" in the plan, including improvements to Mother Waldron Park, across Halekauwila Street from the Pohukaina skyscraper, and "a comfortable street environment for all users."

That is easier to promise than produce. Long-range details of the plan are to be released May 23 on HCDA’s website and open-house meetings are scheduled May 23-30.

The public needs to pay attention and stay engaged. HCDA’s eventual decisions for construction should be subjected to close scrutiny each step of the way in the years and decades ahead.

This is Honolulu in the 21st century — but it’s still Hawaii with a unique sense of place — and there are big changes in store.