Hawaii’s Kakaako planning agency must make full use of an opportunity that won’t come again: enhancing the public enjoyment of the waterfront, in one of the last parcels available to urban Honolulu.

Kewalo Basin and its state-owned small-boat harbor have been an underused recreational resource, and one that has been deteriorating for lack of sufficient maintenance. The improvements to the boating facilities at least now seem to be in better hands with the state leasing the harbor to Howard Hughes Corp., which plans to invest up to $20 million in new slips and other features.

It’s the redevelopment of the small parcels edging the harbor, however, that is key to success. The plan that emerges in the coming months will either add the needed finishing touches on those 2.1 acres, or put up barriers. The place should be as comfortable for residents as for visitors.

Last week a one-year period lapsed, a period during which the Japan-based restaurant operator Bellavita Inc. had exclusive rights to negotiate terms of a lease for part of the property. The same thing happened with the prospective developer of the remaining area, three other Japanese firms comprising Kewalo Waterfront Partners Inc.

Collectively, the entities had proposed an Italian restaurant and other eatery and retail venues, as well as a wedding complex — all of which seemed targeted primarily for the tourist market.

Kakaako approaches the gateway to Waikiki, but the waterfront is simply too important to urban Honolulu residents, hemmed in as they are by rising condo towers, to give over to tourist-oriented attractions.

Now there will be competition to come up with the best concepts, designs that should reflect a sense of place and a Hawaii aesthetic. What emerges should be a blueprint accommodating venues and spaces for residents as well as visitors to gather.

Howard Hughes, which owns the 60 acres of largely upscale developments mauka of the harbor and Ala Moana Boulevard, is expected to submit a competitive development proposal to the Hawaii Community Development Authority, the state agency that owns the parcels. Other bids could be entertained, as well.

This is excellent news. There should be competition, and thorough public review. Already commercial fishermen and tour operators based at Kewalo have expressed some worry about how traffic flow and parking provisions will affect their businesses.

In addition, surfers arrive when waves beckon, and they vie for the 100 parking stalls around the harbor. Parking that accommodates the various uses of the harbor remains an issue to be resolved in the final plans.

Some of the critique from boaters and existing business owners is that harbor-related facilities rather than restaurants and other venues should be developed. Anthony Ching, HCDA executive director, has said more diverse commercial developments would bring new life and activity to the area.

He’s right about that, but that’s not the only metric for evaluating the incoming proposals. What the harbor also brings is a break in the concrete-and-glass maze that’s rising behind it. Kewalo affords a view of the land, sea and sky, and what’s built around it should preserve those elements. Retail and restaurants are important parts of the scene, but there also needs to be green space and places for people to come and simply sit and enjoy their surroundings.

Quite a lot of new Kakaako dwellings will be high-end, especially those with the closest view of the ocean. But community leaders and residents have fought long and hard to keep public access to the waterfront. A redeveloped Kewalo will be key to that — a fun place, and one that’s welcoming to all.