Climate change and sea level rise spurred by global warming threaten the islands from mountain to sea, with the potential for destructive floods and erosion caused by stronger, less predictable storms sending contaminants, soil and debris downhill to a vulnerable ocean. Add that threat to the man-made damage done to our watersheds, from peaks to coast, and the risk rises that a future storm will cause catastrophic damage — not only to the natural environment, but to the dense communities nearby.

That’s one impetus for a welcome surge in federal spending to shore up coastal environments against changing climate patterns and extreme weather.

East Oahu is a recent beneficiary, with an $8 million grant from the National Oceanic and Atmospheric Administration (NOAA) to a group of nonprofits led by Malama Maunalua. The combined groups will work to remediate conditions in the ahupuaa of Maunalua, a land division that includes the watersheds flowing into Maunalua Bay, and to restore coral reefs in the bay.

The project stands out as the first to involve a densely populated, highly degraded area. It’s a forward-looking action, all the more praiseworthy because it is led by a local group that is closely familiar with an area, and should serve as a prototype for similar ventures throughout the islands.

The Maunalua ahupuaa, which includes the Niu, Kuliouou and Wailupe watersheds of East Oahu, could use improvement. Deforestation at higher elevations leads to high levels of soil runoff. Feral pigs add to the problem. Maunalua Bay, battered by the uphill conditions, is an “impaired waterbody” with poor water quality, as assessed by the state Department of Health. Silted with runoff, its coral reefs are some of the most degraded in Hawaii.

NOAA’s grant funds the nonprofit partners to employ an ahupuaa, or ridge-to-reef, strategy to address the problems, alongside state agencies and NOAA itself. The goal is to restore both watersheds and reefs so that they — and we — can persist despite a changing climate.

Before Western contact, Hawaiians’ concept of the ahupuaa incorporated the knowledge that what happens upstream affects downstream ecosystems. Today, more than 90% of the land within the Maunalua watershed is “hardened” — overlaid with houses, driveways, condos, shopping centers and parking lots. Dirt, leaked oil and rubbish on pavements washes quickly downstream. Most streams have been lined with concrete, also pushing contamination and debris quickly into the ocean. Studies of fish in the bay have revealed elevated levels of arsenic and lead.

The three-year effort will include reforestation at higher elevations — removing invasive species, planting native species and installing fencing to keep feral pigs out. Close to 500 acres of the Pia Natural Area Reserve above Niu Valley will be protected in this way.

In populated areas, partners will work with homeowners to use “green infrastructure” that helps capture rain and allows it to sink into the ground — for example, porous driveways — reducing runoff and lowering flood threats.

Streams will be modified so that water can be diverted back into the ground where practical. Wailupe Stream, the only stream in the ahupuaa not channelized, will be rerouted to create shallows and pooling areas, and continue to support native fish and shrimp species.

All of these approaches are suitable for additional ahupuaa, and particularly the Ala Wai watershed, also densely populated, and recognized as a flood threat via the Ala Wai Canal. Indications are that the U.S. Army Corps of Engineers will not be taking an ecosystem approach to its flood control project to protect Waikiki, but that shouldn’t prevent federal and state support for a program similar to Maunalua.

A healthy, resilient environment supports a resilient community. Although NOAA is funding this approach in a heavily urbanized area for the first time, it should not be the last.