The cleanup is still underway in South Maui, but one thing is already clear: this was not just a storm. It was a system failure that has been building for decades. Homes are gutted, some will be rebuilt, some demolished, and many residents, especially those without flood insurance, are facing a long and expensive recovery. Entire neighborhoods are still pulling mud, debris, and silt out of homes that were never expected to flood like this. But longtime Kīhei residents know something different. They have seen this before.
Record Rainfall Hit the Entire System at Once
Maui County is still tallying the damage after what many are calling one of the most significant storm events in recent memory. Some have described it as the heaviest rainfall in more than 70 years. Kona storms are not new to Maui, and the leeward-facing shores of South Maui have always been vulnerable when strong onshore winds push moisture into areas that are usually dry. What made this storm different was not just the intensity, but the scale. South Maui and many other parts of the island were hit at the same time. Upslope catchment areas that are often dry, dusty, and unstable suddenly received intense rainfall and released it downslope all at once. That water carried silt, mud, rocks, and debris through narrow gulches and undersized drainage corridors until it reached the coastal plain, where the system began to fail.
The Floodplain Did What Floodplains Do
One of the clearest lessons from this storm is that the floodplain still exists whether people understand it or not. Water followed the old pathways. It moved through gulches, low-lying land, and historic drainage corridors exactly as it has in previous storms. Many longtime residents were not surprised to see this happen. Some newer residents were. The word floodplain is not decorative language. It is a warning built into the map. Areas that are naturally meant to carry or hold floodwater will do exactly that when the rain comes hard enough. As seen again in Fong’s Gulch, these channels are not optional features in the landscape. They are part of the island’s natural drainage system. When they are narrowed, clogged, neglected, or built around without respect for what they do, the water does not vanish. It backs up into roads, homes, and neighborhoods.
Undersized Infrastructure Was Exposed Again
This storm did not reveal a new problem. It exposed an old one at full scale. Maui County has had studies, plans, and engineering recommendations for years that describe South Maui’s drainage limitations. The same themes come up again and again: undersized culverts, constrained gulches, poor stormwater capacity, and development patterns that increase runoff faster than the land can absorb it. These issues have already been examined in earlier Save Kīhei reporting on drainage and community solutions for flooding. This storm simply pushed the system past the point where those weaknesses could be hidden. Water hit bottlenecks, overtopped channels, and spilled into streets and homes in places many residents have been warning about for years.
The System Was Calculated for Clean Water, But Real Floods Carry Debris
One of the most overlooked problems in South Maui is that stormwater infrastructure may look adequate on paper, but real floodwater is not clean water. When the Kīhei drainage master planning work looked at carrying capacity, the numbers were based on flow through pipes, culverts, intakes, and channels as if the water were moving cleanly. But in actual Kona storms, floodwater does not arrive clean. It comes loaded with mud, silt, branches, trash, rocks, brush, and other debris washed out of the dry upslope catchment areas. That debris clogs intakes, reduces flow, snags on structures, and turns already limited stormwater systems into chokepoints almost immediately.
That is one reason residents keep seeing the same pattern during major storms: overflows at storm drains and gulch crossings that might appear sized well enough in a model but fail in the real world once debris starts piling up. The Waikōākoa Bridge area in North Kīhei near Suda Store has long been one of the places people watch closely. The culvert at Kulanihākoʻi Gulch Bridge gets overwhelmed. The stormwater drain under South Kīhei Road at Waipuilani Gulch is widely seen by residents as grossly inadequate for the kind of muddy, debris-filled water that actually shows up in these events. And these are only the most obvious examples. The same basic problem likely exists across many drainage structures throughout Maui County. Debris is not some unusual extra variable. It is a fact of life in Maui flooding, and when it is not properly factored in, the real carrying capacity of the system is far lower than the paper capacity.
Development Has Reduced Nature’s Room to Work
Nature is actually very clear about what it needs. Water needs room. It needs open land, functioning gulches, protected floodplains, wetlands, and green space where it can slow down, spread out, and soak into the ground. That is not just good for flood control. It is also how rainwater recharges the aquifer. But over time, too much of that natural drainage infrastructure has been compromised. Open areas have been paved, filled, boxed in, or pushed aside for development. Hard surfaces like roads, roofs, and parking lots shed water quickly. They do not absorb it. As discussed in Save Kīhei’s reporting on unregulated development, this shifts the burden onto downstream neighborhoods. Instead of infiltrating into the ground where it falls, stormwater becomes fast-moving runoff that gets pushed onto somebody else’s property.
This Has Happened Before, and the Warnings Were Already There
Many residents have pointed to earlier flood events, especially storms from around 1980, as reminders that this kind of flooding is not unprecedented. That matters because it pushes back against the idea that this was some completely unimaginable event. The individual pieces of this disaster have all been seen before. Heavy Kona rain. Muddy runoff from upslope. Gulches overtopping. Streets flooding. Homes taking water. What is different this time is the scale. So many parts of South Maui and other parts of the island were hit at once that the damage feels bigger, more widespread, and harder to absorb. But the broader pattern was already known. Maui County has had drainage master plans and related studies for years. The problem has never been a total lack of information. The problem has been failure to act on what was already known.
Climate Change Is Making Severe Storms More Dangerous
Climate experts have warned repeatedly that severe rainfall events are becoming more intense and more frequent as the climate changes. Warmer air can hold more moisture, and when that moisture is released, it can come down in heavier bursts over shorter periods. That does not mean every storm is identical, but it does mean the pressure on Maui’s already strained drainage systems is likely to grow. What might once have been considered a rare storm no longer feels rare enough to ignore. If the island does not upgrade both its built infrastructure and its natural drainage protections, these failures will keep repeating under more extreme conditions.
Maui Keeps Studying the Problem but Rarely Solves It
This is where the frustration sets in for many residents. Maui does learn from disasters, but too often only on paper. There are reports. There are plans. There are community meetings, presentations, and consultant studies. There are ideas for retention basins, channel improvements, better culverts, stronger protections for wetlands and gulches, and smarter ways to slow and infiltrate water before it becomes a destructive flood. But implementation is where the process keeps breaking down. The reasons vary depending on who is asked. Some say there is not enough money. Others blame politics, bureaucracy, weak enforcement, or the constant pressure of development. Whatever the excuse, the end result feels the same. The public hears that lessons have been learned, and then the next storm arrives before those lessons were ever fully put into practice.
The Water Is Telling Maui Exactly What Needs to Change
If there is one clear message from this storm, it is that South Maui cannot keep treating drainage as an afterthought. The water needs somewhere to go. That means protecting floodplains instead of pretending they are ordinary building sites. It means preserving and restoring gulches instead of narrowing or clogging them. It means defending wetlands and open spaces that act like natural sponges. It means improving urban stormwater systems so they do more than just rush water off one property and onto another. Shedding runoff as fast as possible may be the cheapest short-term solution, but it is also one of the most destructive. It transfers the problem instead of solving it. Maui needs a system that slows, stores, spreads, and infiltrates water wherever possible, while also upgrading the hard infrastructure needed to protect homes and roads when the big storms come.
This Was a Warning, Not an Exception
The cleanup will eventually end. Some homes will be repaired. Some buildings will come down. Life will move forward because it always does. But this storm should not be treated like a freak event that came out of nowhere. It was a warning written across the landscape in mud, floodwater, debris, and ruined homes. The floodplain got its name for a reason. The gulches got their shape for a reason. The old residents who have seen these patterns before were not imagining things. The real question now is whether Maui County will finally do more than document the problem. Because if the island keeps refusing to act on what nature keeps showing it, the next cleanup will not feel like a surprise either.
Read More
Fong’s Gulch Kīhei Flooding
Community Solutions for Flooding Issues
Drainage
Unregulated Development
