Flat out along the Manukau

After years of pressure from Makaurau Maori, the Manukau is clean and the fish are back.

Cameron the drafthorse hung his huge, interested head over the fence as we strode past. Huge primates in shorts, off for a walk.

Through the kissing gates at the boundary of Ambury Park, and on to the new Watercare coastal track. The sign suggested we could do this 8km walk in one hour 20 minutes. Nope. We took our time and diverted almost immediately, down a side track to the harbour's edge.

We sat on the polished macrocarpa benches of a new bird hide and peered through the slit. The Manukau is famous for wading birds, and out on the roost island were godwits, lesser knots, wrybills and more.

At least that's what the signage said, but we'd forgotten our binoculars, and the camouflage and density of the various wader flocks made them hard to identify.

We confirmed nothing except the distinctive red at-arm's slope of the oyster-catchers' bright bills. Then as we watched, there was a disturbance, and the flocks rose one after another to brush the sky with a sublime avian calligraphy.

Watercare has restored this coastline and put in the new path as a stand-alone walk and a link also for the proposed New Zealand-long trail, Te Araroa.

Teams from Watercare have planted around 270,000 trees. In time passers-by will see the harbour glint through a forest, but the trees right now are only knee-high and as we set off walking again, I consoled myself with what the modernist art critic Clement Greenberg, in describing paintings, used to call "the ineluctable flatness of the surface".

Flatness was good for the view, sea-level, across a shining harbour to the menacing black cone at Manukau Heads, or ground-level this other way to a plump green Mangere mountain.

Royal spoonbills, too, are aficionados of flatness. We came across 90 of these large white birds on another roost island. They are named for their long, black bills so charmingly rounded at the end, and we stood exuding love and respect while the birds grew shifty with suspicion.

Flatness is good for aviation in general. In the southern distance, aircraft slanted constantly at suicidal angles into a line of pine trees, reassembled themselves somewhere out of sight and angled upwards again.

And through the ineluctable flatness also ran Auckland's largest and strangest river.

Once, when writing a story on Auckland's sewers, I descended into the 3m diameter pipes buried under these surfaces and waded downriver for an hour through caverns that seemed, as the poet once said, "measureless to man". The flow within the south-west sewerage connector at that time was only calf-deep, but as all the pipes converge on Watercare's wastewater treatment plant, the volumes build to a torrent.

We approached the plant that dealt to the torrent, as you might a shrine. Huge and mysterious processes were happening behind impervious exteriors, but we were brushed only by a faint whiff of ammonia.

Much has changed here, and in changing, has made the new walk possible: the sludge ponds now made redundant by a subtraction of solids that are simply trucked away; the oxidation ponds, too, now gone. Those ponds used to web the harbour right out to Puketutu Island, holding wastewater for a hopeful purification by sunlight.

Now an in-house ultra-violet gallery blasts the wastewater before the final sterile fluid is discharged on the outgoing tide at 25 tonnes a second - Auckland's biggest flow.

We crossed a road, busy with trucks hauling away the solids for local dumping.

We linked to a track that skirted the dumpground, passed along an avenue of pines, and emerged out at the shoreline again at the new carpark beside Oruarangi Creek.

The harbour was previously walled here to contain pathogens, and the creek was piped over the wall. Now, after years of pressure from Makaurau Maori, and Watercare's restoration, the creek flows naturally to the sea. The sea is clean. The fish are back.

We crossed the creek on the road-bridge safely enough, though a pedestrian bridge is planned soon to span the creek. A galvanised gate on the far side, not particularly well marked, let onto a nicely gravelled path that led past another bird hide, and past the white-shell beaches that the reconstruction engineers labelled, as you do, Beach A Beach B, and Beach C.

By now the Otuataua Stonefields were in sight - a good, emphatic, heaped finish. Volcanic vents once effervesced here, and Maori moved in later to heap and enclose gardens, trapping warmth and expanding the kumara-growing season. The garden mounds, and storage pits, and the drystone walls of later Pakeha farmers are still there.

All up it's an easy afternoon's walk, four-seasons, and all-ages. It's well signposted from the Ambury Park end, but there's as yet no signage at the Otuataua Stonefields to indicate the walk even exists.

Getting there

Ambury Regional Park is just south of Mangere Bridge, 15km (25mins) from central Auckland. From Auckland CBD, follow the signs towards the airport.

Join the south-western motorway (SH20), and head south. Leave the motorway at the Mahunga Drive exit and head west along Rimu Rd, Church Rd, Wallace Rd, Muir Ave and Ambury Rd. Signs point to the Regional Park.

Just inside the main park entrance you'll find carparks and toilets. Lock your car and check the closing time of the carpark.

Other carparks are at Creamery Rd (no toilets) and Oruarangi Rd (toilets).

Buses go along Wallace Rd and Muir Ave.

Contact

For timetable information ring (09) 366 6400, or go to www.maxx.co.nz.

For more information about Ambury Regional Park, go to www.arc.govt.nz.

An annual farm day held each October includes such delights as cow lotto.

Gear

Take water, snacks, a raincoat and binoculars.

The track is daywalk standard, easy but exposed, so take warm and windproof clothing; also sunhats and sunscreen and comfortable walking shoes.

No dogs. Leave all gates as you find them.