The Rising Sea and the Runway: Why Airfield Master Plans Must Now Start With Climate

Field notes

I'm Nathaniel Pyron, a military urban planner specializing in military master planning with an airport and airfield focus. Most master planning starts with a simple question: where does everything go? Lately, on airfield projects, I've been asking a question first that used to come last: where will the water go?

Living and working in Honolulu, that question is never abstract. Typhoon season, king tides, heavier downpours — the Pacific keeps reminding us that the ground under a runway is not a constant. And military planners across the services are coming to the same conclusion: climate is no longer an environmental footnote in a master plan. It is a first-order planning constraint, right alongside mission requirements and airspace.

The numbers explain why. The Department of Defense maintains more than 5,000 installations worldwide, and more than 1,700 of them sit in coastal areas that have been or may be affected by sea-level rise or extreme weather. This is not a future risk — it is a repair bill. In 2018, Hurricane Michael caused an estimated $4.7 billion in damage to Tyndall Air Force Base in Florida, with more than a dozen F-22 fighters damaged. Weeks later, Hurricane Florence dropped 36 inches of rain on North Carolina, inflicting about $3.6 billion in damage across three Marine Corps installations. A 2019 DoD report found 53 of 79 surveyed installations at risk of flooding.

Those are installations my community — planners, engineers, installation commanders — has to keep operational anyway.

What climate actually breaks on an airfield

An airfield is a large, flat, hard-surfaced thing. That makes it predictable for airplanes and vulnerable to water. The failure modes are straightforward:

Flooding. Runways, taxiways, and aprons are graded to move water off the pavement fast. But airfields are also enormous impervious surfaces — millions of square feet that shed water onto whatever is downstream. When a storm drops rain faster than the drainage system was designed for, the water ponds on the field. Standing water on a runway shuts down operations. Flooding of airfield lighting vaults, fuel systems, and navigation aids does worse — it degrades the mission long after the storm passes.

Sea-level rise. Many Pacific installations sit on atolls and coastal plains just a few feet above the ocean. The Defense Department-funded research on the Pacific's low-lying islands has been stark: scientists studying Roi-Namur in the Kwajalein Atoll found that roughly 16 inches of sea-level rise could make wave-driven overwash frequent enough to ruin the island's freshwater supply year-round. Diego Garcia — the atoll the U.S. military uses to launch operations across the Indian Ocean and southern Asia — sits about one to two meters above sea level. When the ground itself is that low, every planning decision becomes a water decision.

Heat. Hotter pavement ruts faster under heavy aircraft loads, and extreme heat strains air conditioning, water, and electrical systems that keep both people and mission systems working. A 2019 DoD assessment flagged dozens of installations at risk from heat and drought alongside flooding.

Storms. Typhoons and hurricanes don't just damage buildings — they close airfields, scatter equipment, and knock out the utilities a base depends on. When Tyndall was rebuilt after Michael, it was rebuilt to a harder standard: elevated utilities, hardened structures, designs that assume the next storm is coming. That's a planning decision, not just an engineering one — where to put the critical nodes, what to harden, what to relocate out of harm's way.

How the planning rules changed

The Pentagon has begun writing climate into the rules that govern how installations plan and build. The FY2019 defense authorization act directed that new military construction in the FEMA 100-year floodplain be built two to three feet above the base flood elevation, and ordered the building criteria — UFC 1-200-01 and 1-200-02 — amended to incorporate long-term, site-specific climate projections. In other words: don't design to yesterday's weather.

To support that, DoD built the Climate Assessment Tool, or DCAT — a screening-level tool that assesses every installation's exposure to eight hazards: coastal flooding, riverine flooding, heat, drought, energy demand, land degradation, wildfire, and historical extreme weather. It runs two warming scenarios out to 2050 and 2085, so planners can compare exposure across sites and prioritize where deeper study — and deeper investment — is warranted.

The department's Climate Adaptation Plan sets the end state plainly: ensure DoD can operate under changing climate conditions, preserving operational capability. For a planner, that sentence translates into site selection, grading, drainage, utility redundancy, and phasing — the ordinary machinery of a master plan, aimed at a new target.

What this means on the drawing board

Here's how climate-resilient airfield planning shows up in practice, at the scale where I work:

Siting first. The cheapest resilience measure is not building in the floodplain. Installation master plans and area development plans are the right place to make that call — reserving low ground for uses that can flood (parking, open space, recreation) and keeping mission-critical facilities on high ground. Every compatible-use decision I write near an airfield now gets a flood question too.

Drainage as mission infrastructure. On airfields, the stormwater system is as mission-essential as the runway lighting. Master plans increasingly treat drainage networks, detention basins, and pump stations as protected infrastructure — sited, sized, and redundant for the storms of 2050, not the storms of 1970.

Harden, elevate, relocate. The three verbs of resilient construction: harden what can't move (hangars, control towers), elevate what must stay (electrical substations, fuel systems), and relocate what's expendable or cheaper to move than to defend. Tyndall's rebuild is the case study every planner knows — and the precedent every installation is now measuring itself against.

Redundancy. A base that loses power, water, or communications in a storm loses its mission. Planning for resilience means backup generation, independent water sources, and utility loops that let parts of the installation keep running when other parts go down. Microgrids — local power systems that can operate independently of the commercial grid — have become a standard line item in installation energy planning for exactly this reason.

Nature-based solutions. Wetlands, dunes, and mangroves absorb storm surge and hold shorelines in place better than seawalls alone, and they're cheaper to maintain. For installations with coastal airfields, the natural systems around the fence line are infrastructure — and they belong in the master plan.

Nathaniel Pyron's rule of thumb: the runway doesn't negotiate with water, either. You can design around it, build above it, or retreat from it — but you can't argue with it.

The principle

Military master planning has always been about putting the right thing in the right place. Climate change just raised the stakes of getting it wrong. A hangar sited in a floodplain isn't a design preference — it's a readiness problem waiting for a storm to activate it. The installations that stay mission-ready through the next fifty years will be the ones whose master plans treated climate as a constraint on day one, not a retrofit on day ten thousand.

The water is already on the move. The plans should be too.

About the author

Nathaniel Pyron is a military urban planner specializing in military master planning with an airport and airfield focus, based in Honolulu, Hawaii. He has served with the United States Marine Corps for the last 3 years as a community planner, based at Camp Blaz and Darwin, Australia, and studied urban planning at Arizona State University, School of Urban Planning. His LinkedIn title is "Urban Planner (Land Use & Airspace)".