Access

Rainbow Reach is 11.2 km down SH 95 (Te Anau-Manapouri Highway). The Kepler Track is signposted on the right and a large DoC sign on the right indicates Rainbow Reach. The unsealed road continues 1.5 km to the parking area by the swingbridge. A shelter and toilet here. So are the sandflies.

Track

Cross the long suspension bridge over the Waiau. This bridge was constructed as part of the Manapouri Power Scheme and opened on 11th September 1976. Views downstream along the Waiau lead to the mountains south of Lake Manapouri, often mystically shadowed in cloud and always moody. Erosion on the banks was as a result of uncontrolled discharge from Lake Te Anau, with larger flows than would normally have occurred. These have now been legislated against.

Cutting a sinuous course through the terminal moraine, the Waiau performs a series of large looping curves, one of which, Balloon Loop, is to the left of the track. This will soon be cut off to form an oxbow lake.

This entire section of track from the mouth of the Iris Burn, past Rainbow Reach to the Control Gates is sited on a huge terminal moraine, which separates Lakes Te Anau and Manapouri and gives the Waiau River it’s upper course. Rivers rarely flow straight, in fact little in Nature does, and the upper Waiau here is no exception.

Cross the boggy section on the boardwalk and take the detour to the lookout platform to admire the mire. Interpretation panels give information on these Fiordland biodiversity hotspots. Over 200 plants species are recorded in these bogs and provide habitat for birds, fish and invertebrates.

Bogs such as this form in poorly drained hollows in the moraine. They act as giant sponges, holding water in times of flood, dissipating flood waters’ energy, then releasing it slowly in times of drought. European pioneers in their wisdom saw bogs, marshes and swamps as stinking holes, the stuff of Hell and completely unsuitable for establishing productive economically viable land. One of their first actions was to set about draining as many wetland areas as possible. It is fortunate some such as Amoeboid Mire remain.

The track now undulates through lowland beech forest with occasional rimu, matai and Hall’s totara. Kahikatea also enjoy their wet feet beside occasional bogs.

20 minutes before Moturau Hut is a signposted 30 minute-return detour to Shallow Bay Hut. The track shortly exits the forest and heads for the beach. On the left is a display panel naming prominent mountains and island on the far side of the lake. A brief description is given on the parameters set by Guardians of Lakes Manapouri and Te Anau on permissible lake level fluctuations. The track continues along the beach then dives into the forest behind the lake arriving at the quaint 6-bunk good old fashioned Kiwi style back-country hut. Retrace your steps to the main track.

Moturau Hut is sited on the toe of a hill behind a beach. The views of Lake Manapouri are sublime, whatever the weather (so long as it’s not pea soup).

Return via the same track.

Geology

A cross section through the profile of a river’s current reveals a line of fastest flowing water, that weaves from one outside bank to the other. This is known as the Thalweg. Carrying more energy, the water has the potential for greater erosion and gnaws away at the outside of the bank. This is why you always see a cross section of a bank on the outside of a river’s curve, while deposition in the form of braids, occurs on the inside of the bend. An idealised course for a river would be a sine wave, however varying hardness on the rock types and fault lines varies this. When the sharpness of a bend becomes pronounced, only a narrow neck exists at the apex of the bulbous curve. Eventually the river bursts through, stranding the former course as an oxbow lake. This is what’s happening at Balloon Loop, so named because the bend resembles the shape of a balloon.

Flora

The sun orchid Thelymitra verosa, with its deep blue petals which only open when sunny, is an attractive plant, and grows on beds of sphagnum moss. Red sundews such as Drosera arcturi, D. spathulata and D. binata also add splashes of colour. These small red plants look harmless, and are, unless you happen to be a small insect that is attracted by the sweet scent and spray of red sepals, cunningly coated in a sticky gelatinous adhesive. The poor insects become trapped, and are slowly ingested by these carnivorous beauties. Other notable cushion plants include the comb sedge (Oreobolus pectinatus) and the moss-like (Centrolepis ciliate).

Fauna

Scaups swim on the waters, fernbirds scurry around the rushes and dragonflies and grasshoppers make forays around the fertile habitats. Celery and bog pine form occasional shrubs in the flats with Dracophyllum oliveri, wiwi, Empodisma minus and sphagnum. A look in any direction, but best noted behind the lookout platform, shows the forest succession from sphagnum moss through tall rushes to celery pine and bog pine on the fringes.

European History

The idea for the Kepler Track was first mooted by prominent Te Anau locals, including Les Henderson and Alf Hexall, as a way to celebrate Fiordland National Park’s centennial in 1988. The idea to build a circular walk with easy public access without the need for a boat was high on the agenda of the Fiordland National Park Board.

Investigations started in the summer of 1985. Chief Ranger Paul Green, John Ombler, John Trotter and Tom Patterson, walked to Mount Luxmore, following a track originally cut by cullers. They walked over the Keplers on a beautiful sunny day, tracing a route roughly mirroring today’s track and dropped into the Iris Burn, the idea sold.

The section from Rainbow Reach to the Control Gates was mostly constructed by the hands of long-time ranger Ken Bradley and others, from the late 1970s. The section to Shallow Bay was completed under the Employment Scheme as a way of keeping unemployed workers doing something. Now there’s a good idea!

A full survey was later carried out and construction of the main track commenced in 1986. Much of the work was carried out by supervised Operation Raleigh volunteers. A small digger (in four parts) and a mechanical barrow were flown in, the first time the region had used mechanical plant in track construction. It took nearly two years to complete the work and the official opening took place late in 1988.

The popularity of the walk has slowly escalated, spurred along by the annual Kepler Challenge, usually held in early December. The event now involves around 400 competitors running the 67 km circuit. Many come from overseas and around New Zealand, but a healthy number are Southland locals. The winning time? Under 5 hours!