New Zealand Tour Map Travel Blog

Many overseas travellers and New Zealanders alike are not aware that these small river crossings can become almost unpassable on the return crossing as river levels can quickly rise.

Heres a little story of a German couples experience on the road to Mt Aspiring National Park.

I was following their small rental car to the start of a very popular road into the park the ends at a large car park known as Raspberry Flat which is popular for walkers and picnickers alike. The road involves crossing 4 or 5 very small rivers that on the way to the car park would only have been 400mm deep.

The day was almost ideal, only partly cloudy with no sign of rain on the road or at the Raspberry flat car park. We headed for our favourite picnic spot and after a few hours playing in the river we headed back to our four wheel drive vehicle.

I noted the mountain forecast before our trip mentioned possible rain at higher altitudes. Although this was not evident from our valley position, the first of the river fords clearly indicated that there had been rain somewhere. The depth of the river had almost doubled to less than a metre and was flowing very fast. This was not a problem for a 4W drive vehicle that was also equipped with a snorkel.

As I approached the second crossing I noticed the small rental car that I had been patiently following previously. It was “nose” in the deep part of the small river with water well above the front wheel.

The German couple were very distressed and wet. They could not understand why their cars engine had just stopped mid way through this small and relatively shallow river crossing. I pointed to my vehicles black plastic snorkel snaking its way from the side of the engine up past the side of the front window edge. I explained that the purpose of this device was to move the engines air intake high up to the top of the roof.

Most medium size cars would not have sucked air through the engine air intake in those conditions however the Germans car was small and low to the ground. They also could not understand how the river rose so quickly in the space of a couple of hours in clear weather. Perhaps they don”t have mountains in Germany!

After I towed their car out of the river they tried in vain to restart the engine. On the road back to Wanaka I explained how mountain fed rivers can rise quickly from rain that may be falling far from view and the issues of water being sucked into the engine.

In their case the water was not above the engine air intake. It was the velocity of the water hitting the engine, gurgling and splashing the air intake that created the problem. Even a small amount of water sucked into the intake will cause the engine to stop with little chance to restart it.

These travellers are one of many who get stuck attempting to cross small river fords. Like them most are rather unlucky rather than being naive to the dangers. It is however a timely reminder to check not just the local weather but also the mountain forecast.