Thought it was time to exhale, when Tropical Storm Olivia finally swept away to the west-southwest? Not so fast.

If the cyclones Olivia and Lane taught Hawaii anything, it was that the current storm patterns are defined by the parameters of an extended weather disturbance. This would be one in which the worst damage comes from the flooding and rain clouds that trail along behind, after most of the wind dies down.

It’s essential that the community not let down its guard prematurely.

On Thursday, while much of the state sighed with relief (excepting poor Maui County, which bore the brunt of a direct hit), more startling news caught people unawares. Overflowing sewage. “Brown water” advisories for Oahu residents and visitors, warning against venturing in for an ocean swim.

Topping it off, the Honolulu Board of Water Supply was, for a time, scrambling to siphon off water contained behind the dam of Nuuanu Reservoir No. 1. Located near Oahu Country Club, the reservoir was collecting the pelting morning downpour, and its surface level was rising above where officials wanted it to be.

The water board called in help to pick up the pace of pumping, and when activity drew media attention, the agency issued a statement explaining the problem.

Ernest Lau, board manager and chief engineer, added that there are plans ready for emergency response, including the potential of evacuating some 10,000 residents downstream of the reservoir should there ever be an overflow crisis.

Not that there was ever such a crisis, mind you: Lau assured people within hours that the dam itself was never in danger of a breach, that the water was just getting close to reaching the opening to the spillway. That’s like a release valve keeping the reservoir from overtopping the dam.

But at the time nobody was sure how long the rain might persist. Had it continued for much longer at that volume, there could have been a spill, causing more flooding of streams.

Ultimately, the Board of Water Supply did need to lay out the facts of its emergency plans, though doing so in calmer weather, when people’s nerves were less frayed, would have been ideal.

People do still remember bitterly the deadly breach of the Ka Loko Dam on Kauai. It spurred a state crackdown, requiring management plans for the state’s dams. But the tragedy, which claimed seven lives, even now remains in the public consciousness.

The good news is that the water board now is working on a broad community education outreach project, to explain to neighbors of the board’s three state-regulated dams what to expect in an emergency.

The rest of the state could use a bit of education as well. The fact is that Hawaii remains two months away from the end of hurricane season and, although forecasters expect a bit of respite in the near term, experts are advising people to expect the unexpected.

Some of the erraticism of tropical cyclones has been a constant, but with improved forecasting technology and heightened public attention, people simply are more aware of it. But climate change has affected the temperature of the seas, increasing the uptake of moisture in storm clouds, resulting in sustained heavy rains in the storm bands that follow behind the organized storm system.

Hawaii comprises a train of small islands, with limited evacuation options, and even more limited infrastructure for handling all this water. Storm drains and wastewater treatment plants lack the capacity to bounce back from Lane, Olivia and their siblings to come.

And — now we know — so do the reservoirs.

Further, the state’s agricultural industry, already under duress from the costs of land and other factors, can be dealt a severe blow — even from storms that, unlike the deadly Hurricane Florence in the eastern U.S. and Typhoon Manghut in Asia, are relatively mild.

Finally, nobody needs to be reminded that such devastation leaves a dent in the appeal remote Hawaii has to tourists. Setting standards in land-use planning and construction that strengthen the state’s resilience has become imperative — not for the misty future, but for right now.

It’s become increasingly difficult, if not impossible, to ignore the actual effects of climate change, from king tides to weather extremes. Gov. David Ige and Mayor Kirk Caldwell were part of the global gathering at a climate conference last week in San Francisco. Officially, Hawaii recognizes the threat, and has positioned itself to deal with it.

But have the rest of us had our reality check?

Of course, everyone is feeling tired, ready to put this in the past and drink in Hawaii’s famous weather. A year that began with a bogus missile threat and included a volcanic eruption and multiple storms has residents reeling with disaster fatigue.

So, OK. Take a deep breath, Hawaii. Enjoy a nice weekend.

Then we have to get back to the need for planning, preparedness and vigilance. We’re in for more stormy weather — and that’s the inescapable reality of it.