The floodwaters have eased and it's time to look at what Maitland has experienced over the past couple of weeks. We need to put what's happened in context and work out what we can learn from the event to build a more flood-resilient future.

First, where did the July 2022 flood come from and how bad was it? At the Belmore Bridge gauge it peaked last Friday at 10.41 metres as the 13th-highest flood known since 1820. That made it well short of the great floods of Maitland's history those of 1955 (12.1 metres), 1949 (10.96 metres) and 1893 (11.16 metres). But it was the highest flood ever recorded in Maitland in July, and it caused substantial problems for two groups of people - the farmers on the floodplain and those (farmers and others) who were isolated for days or still are.

The event was triggered by a low-pressure trough that lingered along the coast for nearly a week. Three 'cells' (east coast lows) formed in it. The first of these drenched the South Coast and the second brought significant rains to the catchments of four tributaries of the Hunter River Wollombi Brook and Black, Anvil, Fishery and Wallis creeks.

That rain produced a minor flood which peaked at 7.1 metres at the Belmore Bridge last Monday (4 July). At that stage there was no flooding upstream on the Hunter at Singleton, indeed barely a fresh there and further up the valley, and not much in Wollombi Brook. The other tributaries noted between them brought flooding to rural areas around the town of Maitland.

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The second and third of the weather cells caused huge falls over the catchments of Wallis and Fishery creeks which caused the bypass (Les Darcy Drive to the New England Highway) to be closed. There was also very heavy rain over the Wollombi catchment, the floodwaters from which brought the flood to its eventual peak at the Belmore Bridge on Friday, 11 July.

Overall, the flooding had many parallels with what happened in 2007 as a result of the so-called 'Pasha Bulker' flood. Both floods were caused by east coast lows, the predominant weather mode that produces winter flooding on the Hunter. On both occasions the heaviest falls were over the catchments of the southern tributaries. The Paterson and Williams rivers, entering from the north, came into play only late in the event (when the third east coast low-pressure cell struck) and then to only a limited extent.

Things could have been much worse had the rainfalls been like those of Kangaroo Valley on the South Coast, where more than 800mm was recorded in three days last week, or at Brisbane which a few months ago saw more than 1100mm (roughly the city's annual average precipitation) in a similar period. On Wednesday and Thursday Taree had 307mm in one 24-hour period, its heaviest one-day fall for 140 years.

This time only small portions of the Hunter catchment had very large falls. In 1955, almost all of it (except the Wollombi Brook) was severely hit. Back then in Maitland there were huge flows down the Oakhampton Floodway and more than 20 houses in Mount Pleasant St were destroyed. Parts of the Long Bridge collapsed. The rather primitive levees of the time were breached in many locations and the damage done to dwellings and commercial interests was massive. Recovery was long and painful.

In the scheme of things this has not been a devastating flood. But it has had unpleasant consequences of considerable significance to some in the community (in particular farmers and those who were or are still cut off), and it is a reminder that floods still matter. As it happens we have had, by Maitland's standards, a relatively flood-poor period since about 1980, and the fact that we have had five floods over the past 18 months may suggest that we have entered a more flood-rich era. Our history over the last century and a half is one of roughly 30-40 year periods of flood richness followed by 'flood poverty' for similar lengths of time.

Within these long periods there appear to have been shorter 'sub-cycles': Maitland had five years (2016-21) when no floods were recorded at all at the Belmore Bridge gauge, and now we have had five in only several months. Between 1949 and 1955 we had flood after flood after flood, and several were severe including the defining and most disastrous flood of our history, 'the 1955'. 'Clusters' of floods occurring in quick succession, followed by long periods with none at all, are the Maitland norm. This is also the case elsewhere in Australia.

And every now and then we get a really big one, as Lismore did earlier this year. We should not forget that: big, invariably disastrous floods are inevitable, even if they don't occur frequently. They are part of the Maitland experience, and sometimes they overwhelm us and our coping strategies. Our levees, which have performed well for over half a century, will one day be overtopped. Indeed they are designed to be in rare, very large but nevertheless certain-to-happen floods.

We should not forget that, or that the 1955 flood will one day be exceeded in height and severity. Nor should we forget that we are only halfway through July, a time of year when east coast lows strike frequently. The ground is saturated and another rain event now could plunge us right back into a flood, and possibly a big one. Nobody would want that.

Mr Keys books are: Maitland, City on the Hunter: fighting floods or living with them? (2008) and Maitland Speaks: the experience of floods (2020)). The second of these books can be bought from McDonald's Bookstore in High St, Maitland.

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