The Marsh Behind Kailua Is Having a Very Busy August

Stand at the end of Kaha Street, where the pavement gives way to a gravel path into Kaha Park, and you are looking at roughly 830 acres of the largest wetland left in Hawaii. The same view is available from the top of Ulupō Heiau, or from the Na Pōhaku o Huawahine trail off Kapaʻa Quarry Road. Kawainui Marsh does not announce itself the way Kailua Beach does. It sits low and green behind the town, bordered by Kalanianaʻole Highway, Kailua Road, and Kapaʻa Quarry Road, doing the quiet work of catching runoff before it reaches Kailua Bay.

For most of the year, that quiet is the point. This month it is not. Over the past three weeks, the marsh and the ground around it have produced three separate local stories: a fight over where Oahu puts its trash, the yearly return of a bird many Kailua residents consider a member of the household, and a bridge project that has reshaped the morning commute. Treated separately, they read like three unrelated items in a community newsletter. They are not unrelated. They are one piece of ground doing four or five jobs at once, and this is the month all of those jobs are colliding.

One Watershed, Doing Several Jobs

Kawainui Marsh is not decorative. The state's Division of Forestry and Wildlife lists it as a federally recognized waterbird recovery area, home to four endemic and endangered Hawaiian waterbird species, and a functioning part of the Koʻolau Poko watershed that provides flood control and sediment filtration for the urbanized valley below. Water moving through the marsh eventually reaches Kailua Bay by way of the Kawainui Canal. That single sentence, water in, water out, is the thread connecting everything below.

The marsh has also carried a harder history than its current calm suggests. The surrounding Kapaʻa watershed hosted major quarry operations, at least two municipal sanitary landfills, and an unrecorded county dump over the past several decades, all draining toward the same wetland now protected under the Ramsar Convention as a wetland of international importance. The ground remembers what it has been used for. That is worth knowing before the next section, because the city is proposing to use it again.

The Birds That Already Treat It as Home

Long before any of this month's headlines, the marsh and the lawns around it were already doing one job with no controversy attached: hosting kōlea.

The Pacific Golden-Plover spends its winters on Oahu lawns, parks, and marsh edges after a nonstop flight from Alaska, and the marsh's fringes and surrounding yards are exactly the kind of ground they favor. According to Kōlea Count, the citizen-science project run by the Hawaii Audubon Society, female birds typically arrive first, from late July into early August, with males following mid to late August. The Honolulu Star-Advertiser's Kokua Line column addressed a reader's plover question on August 6, walking through the same male-first arrival math local birders have tracked for years.

What makes kōlea different from almost any other seasonal marker in Kailua is that the same individual bird tends to come back to the same patch of grass, year after year. One kōlea documented on Kōlea Count returned to the same Kailua yard for 15 years, learning to eat mealworms from its owner's hand. Residents up and down the Windward side name their birds. Jake. Lady. Mr. Necker. The marsh's edges and the surrounding neighborhood lawns are, in effect, a long string of small, fiercely defended territories that a handful of four-ounce birds have decided are worth flying 3,000 miles to reclaim.

The point is not the bird trivia. The point is that this same ground, prized enough that a plover defends four square feet of it for over a decade, is also the ground now under discussion for something considerably less welcome.

The Quarry at the Marsh's Edge

In late July, Mayor Rick Blangiardi's administration named Kapaʻa Quarry, an HC&D-operated aggregate site near the H-3 freeway interchange, as the city's preferred location for Oahu's next municipal landfill. The current site, Waimanalo Gulch Sanitary Landfill in Kapolei, is under a state Land Use Commission order to close by March 2, 2028, and the city has spent years failing to find anywhere else that clears legal and political hurdles. Kapaʻa Quarry does not sit over a drinking water aquifer, which keeps it clear of a law passed just last year. It does, however, sit inside the half-mile buffer zone that Act 73, a 2020 state law, requires between landfills and homes, schools, and hospitals. Moving forward would mean the legislature repealing or amending that law.

State Rep. Lisa Marten, who represents Waimanalo, Enchanted Lake, Keolu Hills, Kailua Gardens, and Lanikai, was blunt about what the site actually borders.

"Like this amazing wetland the largest wetland in our state, cultural artifacts, heiau in this area as well."

Honolulu City Councilmember Esther Kiaʻaina has raised a different objection: the quarry is one of the island's largest sources of concrete for construction, with an estimated 50 years of aggregate capacity remaining. Converting it into a landfill trades a long-term construction material supply for waste disposal, on a piece of ground that Windward lawmakers point out has already hosted five landfills since 1940: the Aikahi Landfill, Kawainui Dump, Kapaʻa Central Landfill, Kapaʻa Landfill, and Kalaheo Landfill.

There is a physical reminder of what that history left behind. Pahukini Heiau, a luakini heiau believed to have been built around 1110 A.D. by High Chief Olopana, sits above the now-closed Kapaʻa landfill, overlooking the marsh. Community groups and the Kailua Hawaiian Civic Club have spent more than three decades trying to protect and restore access to it. It is not an abstract cultural reference. It is a stone structure sitting on top of the last time this exact question got answered the same way.

The city's position, delivered through mayoral spokesman Scott Humber, is that Oahu generates roughly 1.5 million tons of solid waste every year and that waste has to go somewhere. That is true. It is also true that a Kailua resident wrote to the Star-Advertiser on August 10 describing what living near the current Kapaʻa Transfer Station already involves: the smell during Kona wind conditions, and truck traffic crossing the Pali, Likelike, and H-3 highways. No decision on Kapaʻa Quarry has been finalized. The legislature has not repealed Act 73. But the site under discussion is the same low ground the marsh drains, a few hundred yards from where a kōlea is currently re-establishing its winter territory.

The Bridge That Crosses All of It

If the marsh is the low point collecting water from the valley, the Kawainui Canal is where that water leaves, and the North Kalāheo Avenue Bridge, City bridge No. 445, is the crossing over it. That bridge has been under active rehabilitation since March 30, 2026, when sheet pile installation began. Work paused for a utility conflict and resumed on August 10 after the contractor coordinated with the utility company, and the city's Department of Design and Construction has published a rolling schedule of contraflow and detour patterns through mid-September.

The city has also requested a police officer at Kaha Street and Oneawa Street, the same Kaha Street that dead-ends into the marsh trailhead, to help direct traffic during the heavier weeks. None of this is happening at that bridge by coincidence. It exists because the canal exists, and the canal exists because the marsh needs somewhere for its water to go.

Same Ground, Same Season

None of these three stories started this month. The marsh has been draining this valley for centuries, the kōlea have been returning to the same lawns for as long as anyone has been counting them, and the argument over what to do with Kailua's old quarry has surfaced before, more than once. What is unusual is having all three active in the same few weeks, on the same few hundred acres, in a way that makes the connective tissue hard to miss once you see it.

If you live near the marsh, the bridge, or the quarry road, the next few weeks are worth paying attention to regardless of where you land on the landfill question. The legislature has not acted on Act 73. The bridge schedule will keep shifting. The birds, at least, have already made their decision.

If you are trying to understand how any of this touches a specific address in Kailua, whether it is proximity to the transfer station, the marsh, or the bridge detour route, that is exactly the kind of local detail Kalei Wodehouse works through with clients every week. Schedule a personal consultation if you would like to talk through what it means for your street.