Distance: 3.7 km (2.5 DOC hours) - Unmarked route, clear - Moderate terrain
Altitude: 415m to 446m. Gain: 79m. Loss: 102m . Gradient: 3 deg (Gentle)
Skills: - Prolonged rivers (4/6)

Unmarked route, clear (7/9)
Unmarked route, follows obvious geography (river, spur, trail, etc)

Primary, mapped (1/5)
Formal route, on maps, principal access to hut or along range / catchment

Gentle (difficulty: 2/5)
Gentle slopes

Moderate (difficulty: 3/5)
Low scrub in open or bush / river rocks

None (difficulty: 1/7)
No alpine skills required

Prolonged rivers (difficulty: 4/6)
Frequent river travel - impassible after rain, risk of getting trapped

None (difficulty: 1/7)
No alpine skills required

Between Central Waiau Hut and the swingbridge the former sidle track has returned to bush - it could be followed if the river were up, but it is effectively a 3km bushbash with no real track present.

The normal route is now down the riverbed with 7 crossings being the norm - the last at the hut. The river is knee deep in low-moderate flows, and was waist deep (and marginal for a single person) even 2 dry days after a single day of steady rain.
From the swingbridge, tracks lead down either bank - though for travel to Central Waiau the western bank was more convenient.

I crossed near the southern end of the flats and climbed onto terraces ont he true left (east) which continued with good travel for 800m, ending at the 2nd sidestream. A brief scramble took me past the sidestream and back to the main river 50m downriver. Another crossing to the western bank was soon necessary, and then a return (hard, deep and fast) beside pt474. A track cuts off the southern part of this bend, crossing north of the hut, recrossing to the east, then crossing one final time at the hut itself.

Note: Described in the reverse direction to your journey

Upriver from Central Waiau Hut the former sidle track has returned to bush - it could be followed if the river were up, but it is effectively a 3km bushbash with no real track present.

The normal route is now up the riverbed with 7 crossings being the norm - the last at the swingbridge. The river is knee deep in low-moderate flows, and was waist deep (and marginal for a single person) even 2 dry days after a single day of steady rain.

Crossing above the hut, a track cuts off the first bend, returning to the eastern bank 300m upriver, where another track cuts off part of the next bend. No obvious track leads up the next section, and with the river up I was forced to bushbash 500, up the western bank before crossing back to the east. From the slight bend and confluence 800m upriver of pt484, good terraces start on the true left - a bit of a scramble to get onto them just below the confluence, but great going once there. These terraces and 800m later at the start of the flats - 1.2km below the swingbridge - and avoid 4 more crossings.

Once on the flats the river is wider and shallower, and an easy 6th crossing took me back to the western bank, where a good ground trail up grassy flats leads past several good camp spots, ending at the swingbridge.