This absorbing analysis to measure the movement of pools in the lower Tongariro River has taken 19 years of patient study. Anglers often have to survive the cold exposed river conditions with desperate periods of deep meditation waiting in anticipation for a strike. This provides enough time to study the annual movement habits of stray pipes. They act as visual markers to demonstrate how much the character of pools changes from aggradation and drift downriver between seasons. Fly fishing distractions can be so fascinating…

Tongariro River – 22 June 2006 at the Braids car park. The Waikato Regional Council contractors all organised to construct a ramp across the “Plank Pool” as it was known then. A large plank prevented cars from entering the bypass. According to the “authorities”, the aim was to remove gravel from the Braids – remember the Swirl Pool, Honeypot, Spot X, etc. – as a flood prevention measure. According to locals it was more about turning the Braids into a shingle quarry. As indicated in the photo below, there was ample evidence of their work further downriver at the time.

The work progressed well. The bypass was much wider back then and highly regarded by anglers for easy wading and great summer dry fly fishing. SWMBO, Honorary Clerk of Works, (She Who Must Be Obeyed tries to manage everything She sees) inspecting it on 23 June, 2006 below.

Two days later the weather won. The new access road was washed away.

So what is this blog all about? The large concrete pipes have been monitored by fishos ever since as they slowly make their way downriver during each flood. They provide easy visual illustrations of how the ever-changing contours and geography of pools alter every season.

Rather than go on and on monitoring the pipes annual migration movement, the next photo below was taken 16 years later, in September 2022. By then the pipe had been moved about 100 metres below the site of the original ramp. It looked as though it would stay in this location as it was buried end on end.

But then the latest two 700 cumec floods earlier in 2025 arrived… The pipe has been flipped over again and is now a further 100 m downriver at the lowest point of the braids.

At their present rate of progress a pipe would take until 2095 to reach the delta, but below the braided area the speed and power of the flow diminishes and the wide meandering river lacks sufficient hydro power to move them much further. By next season, a giant brown trout will have taken up semi-permanent residence in the pipe to emerge only at night to feed when the anglers are not there.

Despite the ugly scenery of willow snags, these lower river pools still attract more anglers than any other pools on the Tongariro River. The Braids car park is full most weekends, with most keen anglers heading further downriver for 20-30 minutes towards Reeds and beyond to intercept and ambush fresh run trout on their spawning runs. The WRC tried to flush it out when they excavated a canal beyond the Braids down the TLB, but the river has since reverted to the original course. Nature always wins on the Tongariro River.

Tourist anglers have remarked that in any other world-famous trout fishing river, the authorities would insist contractors remove pipes and other debris left behind after their quarry excavation plans failed. But perhaps after 19 years the Waikato Regional Council are now using them as visual markers to assess aggradation effects… If the annual study of pipes becomes boring, occasionally there are other more enjoyable distractions for anglers on the Tongariro River.