Townsville’s 2025 floods

This is just a short overview of our big rain event in Jan-Feb to provide context for Too many 1-in-100-year floods (next post).

Two long posts about our 2019 floods, one about the weather event and one about its consequences in daily life, provide the basis for all my comparisons. Back in 2019 the BOM issued a Special Climate Statement, which I quoted from at the time, but they haven’t (yet) done so this year. All my rainfall data is from their site, although I have often rounded-off their figures.

Comparison of 2019 and 2025 rain events

In 2019 we had 1390 mm over 13 days while in 2025 we had 1260 mm over 16 days, i.e., about 10% less overall, so the two events were certainly very similar.

However, by far the wettest two-day span came this year, 545 mm compared to only 375, a 45% difference. This makes me think that peak “2019-repeat fear” was due to those two days, Feb 1 and 2. We had already had 100 mm over the previous four days and then it started to really rain. A couple of days later we had a respite and our fears eased.

Casual conversations around town suggest that this year’s event was not as difficult for most of Townsville as 2019. Most people thought that was largely because the dam releases were better managed. That may be true, too, but the fact that the average rain rate this year was so much lower than in 2019 (110 mm vs 80 mm, a 35% difference) must have made management easier.

Ross Dam in 2019

That said, the dam did help, a lot, in 2019. According to the FAQ’s on the council’s dam management page:

How much water did the dam store during the 2019 flood?

During the monsoon event from 27 January – 8 February 2019, the total volume of flood waters received in the Ross Dam catchment would have filled the dam (to Full Supply Level) nearly four times over (932,748 ML).

How severe would the 2019 flood been if the dam had not been there at all?

The peak inflow into Ross River dam occurred on 3 February 2019 with 4,900 m³/s of water flowing into the catchment. The peak outflow of water at the spillway on the same day was 1,900 m³/s. The dam was able to reduce the volume of flood water released downstream by 258%.

Ingham in 2025

The heaviest rain in the 2025 event was on the coast to the north of Townsville. The top ten February rainfall totals, nationally, were all in that area: Paluma (2920 mm), Cardwell Range, Mutarnee, Macknade Mill, Ingham (2050), Allingham, Rollingstone (1970), etc, down to Townsville at number 18 with 1200 mm. Paluma is the only one that isn’t on the coastal plain. (My chart doesn’t include the end of January but those few days wouldn’t change the rankings much.)

Ingham had 1940 mm in the start of Feb , with 1160 over Feb 1 – 2 – 3 and 502 on Feb 3 alone. That was after 450 Jan 28 – 31, making nearly 2400 for the whole event, nearly twice what Townsville got. No wonder our news was full of the flooded town!

Ollera Creek took second place in our news rankings for a while, because the bridge on the highway was washed out. Where is Ollera Creek? At the foot of the Paluma Range.

Our major roads to the south and west were also cut (again!), as they often are by heavy rain. The fact that our Premier was an Ingham boy and a Townsville resident may improve our chances of getting the upgrades we need; let’s hope so.