July 2026
Recoded rainfall eased to 164 mm at the site of the Waipa Stream spawning trap in July, with no flood events recorded. Overall fish numbers were down compared to the previous month, where rainfall was much higher.
Brown trout numbers in particular dropped, with 71 fish processed, compared to 157 in June. This is partially due to reduced flows but also reflects historic patters, where brown trout tend to start their migration earlier, peak earlier and drop away earlier. The longest and heaviest brown was a hen of 660 mm and 3.9 kg.
Rainbow numbers were also slightly down. Rangers processed 241 fish, which was a reduction of 40 fish compared to the previous month. The longest rainbow (590 mm) was a hen with a fin-clip scar indicating it was a repeat spawner. The heaviest was a jack that had also spawned previously, which weighed 2.45 kg.
We anticipate higher rainfall and increased flows will trigger further pulses of rainbow trout heading upstream.
Graphs and tables July 2026 (XLXS, 67K)
June 2026
The return of significant rainfall at the site of the Waipa trap prompted a surge in fish numbers, with both brown and rainbows significantly up on the previous month. A total of 438 fish were processed with rainbows now in a clear majority. There was a single flood event.
Fishery Rangers processed 157 brown trout through the trap in June, which is much higher than the 35 trout processed the previous month, and nearly double the numbers recorded during June last year. The longest and heaviest brown was a hen that recorded 690 mm, 4.05 kgs.
Rainbow trout numbers trapped in June also jumped dramatically compared to last month. Only 36 fish were processed in May, compared to 281 recorded in June. The heaviest rainbow was a hen that registered 2.2 kgs, while the longest was another hen of 580 mm.
Data confirms the spawning migrations are in full swing, with large numbers of trout are in the rivers. Fresh fish will regularly enter the rivers and move rapidly upstream during rain events.
Graphs and tables June 2026 (XLXS, 67K)
May 2026
The Waipa Stream fish trap was recommissioned in May, enabling Fishery Rangers to collect data about trout spawning migration patterns. This important work allows consistent data collection across multiple years at this important Tongariro River headwater stream.
Rainfall was very low this year with only 52 mm recorded at the site of the fish trap throughout May. There were no flood events.
Brown trout spawn early but limited rainfall and reduced flow rates likely impacted the numbers reaching this headwater stream. Fishery rangers processed only 35 browns, which is higher than the 23 trapped last year but much lower compared to 80 fish recorded in both 2022 and 2023. Overall, browns averaged 558 mm in length and 2.2 kg in weight. These figures are slightly down on last season and well below the exceptional fish encountered in 2022, where browns averaged 607 mm and 3 kg respectively.
The rainbow trout numbers trapped this year also reflect the reduced flow rates. Only 36 fish were recorded compared to the 71 processed last year. Rainbows averaged 478 mm and 1.23 kg which is slightly below last years figures but significantly down on the solid fish trapped during May 2022 (531 mm and 1.9 kg).
We will continue to publish updates from the Waipa Stream fish trap throughout the winter season.