In the two decades since the Koa Ridge development first appeared on the drawing board, the planning landscape has shifted around it.

Ground was broken on Thursday for the Central Oahu planned community, after a protracted and sometimes bitter land-use fight, pitting environmental groups against the developer, Castle &Cooke Hawaii. The battle was fought in the state’s high court and before the state Land Use Commission.

Ultimately the project fell within urban classification and was allowed to go forward. This happened much to the disappointment of neighboring communities who worried about adding to the already congested highways, and of those who advocated instead for the preservation of agricultural land and open space.

In the meantime, however, the demand for housing continued to accelerate on Oahu, compelling leaders to rethink how to fill the demand.

Koa Ridge, a $2 billion project, now is slated to yield its first finished homes in mid-2019. The full buildout, taking about a decade, will include 3,500 homes, priced from the high $300,000s to the low $900,000s. Castle &Cooke struck a deal with the city to provide 30 percent of these, or 1,050 homes, as affordable to moderate-income households.

But given that the shortage of homes needed on Oahu in the next decade is closer to 25,000, the solution to the housing crisis can no longer lie in sprawling subdivisions such as Koa Ridge, occupying 576 acres.

Instead, city officials must seize on the potential for more densely built communities to rise around the 20 stations of the Honolulu elevated rail system, all along its 20-mile alignment. Development regulations to guide this process are supposed to provide incentives for many more of these housing units to be affordable where the need is greatest, for families earning between 60 and 80 percent of the area median income.

How well this succeeds depends on the will of elected officials to hold developers to a firm mandate, and that already has been shown to be wavering. But in any case, the future lies in neighborhoods that are more urbanized and less dependent on individual cars for transport to work and daily routines.

Koa Ridge, which lies a good distance from the rail line and on a freeway and highway corridor that’s already packed every rush hour, is at a distinct disadvantage there.

Transportation planners need to start now to devise links to the rail system, whether that means carpools, shuttles, bus lanes or other routes to the park-and-ride facility planned at Pearl City to the south. Residents of Koa Ridge, and even Mililani to the north, should not be discounted as regular users of the rail system.

In the 20 years since the inception of Koa Ridge, fortunately, there have been changes that will work in its favor as well. The long-debated and anticipated “second city” is taking shape in Kapolei to the west. The University of Hawaii at West Oahu now has a campus, and there are city and state offices located in the town center. There is a major shopping center, Ka Makana Ali‘i, open for a year now, that is a big draw.

Within its own boundaries, plans for Koa Ridge have filled out as well. At the groundbreaking ceremony, Castle &Cooke President Harry Saunders recalled when the project was envisioned as a retirement community with a medical complex. Even as the concept evolved into a community for a more diverse population, it was still assumed to be a bedroom community, most of its working residents heading out for jobs closer to urban Honolulu.

Now there are blueprints for shops, restaurants, a hotel, a hospital and a light industrial park.

These are positive developments, hopeful signs that increasingly, West Oahu residents will feel less of a pull toward town and that more of them will be able to work and play closer to home.

Lawmakers and planning officials at both city and state levels must continue to direct more such opportunities near the second city. The center of gravity is shifting away from Honolulu proper, and that is a good thing if the goal is to make Oahu more livable.

But it’s not the only factor. Striking the right balance for this island means preservation of the open space and farmland that remain, largely to the north of Wahiawa and around Kunia, as well as in parts of the Waianae Coast and North Shore. Ensuring that breathing room persists for future generations means accepting more housing in the areas that are already urbanized.

Certainly there will be single-family homes built in pockets here and there, but not on a large scale, at least no longer on Oahu. Those who have supported Koa Ridge surely are pleased to see more homes coming into the pipeline, but the reality is that this community, and the remaining subdivisions set for Kapolei, represent the end of an era.

Home is always where the heart is, but now that’s more likely to be in the heart of the city, too.