Mangatangi Reservoir Fishing: Trout from the Dam, Hūnua Ranges

Last updated October 2026

Mangatangi Reservoir is one of Watercare’s water-supply lakes in the Hūnua Ranges, and one of the two Hūnua lakes that Fish & Game lists for trout fishing. It holds wild rainbow trout, with hatchery fish released to add to them.

Fishing is allowed only from the dam face, inside the signed areas, and only with a fly or an artificial lure. You need a Fish & Game licence and a free Water Access Permit, which you fill in yourself at the kiosk.

At a Glance

Location

Mangatangi Dam, eastern Hūnua Ranges, at the end of Workman Road

Type

Large water-supply reservoir behind a curved, grassed embankment dam

Main species

Rainbow trout (wild fish plus hatchery releases); tench, perch and rudd also present

Method

Fly or spin with artificial flies and lures only; no bait

Where to fish

The dam face, inside the signed areas only

Season

Open all year

Permit

Free Water Access Permit, self-issued at the fishing kiosk

Licence

Fish & Game sports fish licence (Auckland/Waikato rules)

Access

On foot up the dam access road; no driving to the dam

Tides

None

What You'll Find Here

Mangatangi is a drinking-water lake in a protected catchment managed by Watercare, so the public can fish only a small part of it. Anglers are kept to signed areas of the dam face, and there is no fishing from the rest of the shoreline. Its neighbour to the west, Mangatāwhiri, works under the same rules.

From above, the dam is a long curve across the southern end of the lake, with a road running along its crest and a grassed back face stepped with benches.

A round intake tower stands in the water off the western half of the dam. Workman Access Road comes in on the eastern side, and above the dam the lake spreads north into several bush-lined arms.

The trout in the Hūnua reservoirs are wild rainbows. Mangatangi is the one of the pair where hatchery-reared fish are also released to add to the wild stock. The lake also holds tench, perch and rudd. The current Auckland/Waikato regulations list it as open all year to fly and spin fishing.

How to Fish Mangatangi Reservoir

On the dam face

All the fishing is done from the dam, so you are casting out over open water rather than working a shoreline. The water is deep away from the edge, which is why long leaders matter here.

Read the signs at the dam before you start: they mark where you may stand. Spread out along the open stretch, and give the next angler room for a back cast.

What to use

• Nymphs: the most productive method. Fish & Game suggests a floating line, a monofilament leader of 3 to 5 metres with an indicator about 2.5 m above the fly, and a very slow retrieve with the odd twitch. Small caddis larva imitations are the most popular, and a Pheasant Tail is a good standby.
• Wet flies: green or black Woolly Buggers, or small spider patterns retrieved slowly in the evening.
• Dry flies: an Adams for daytime mayfly hatches, and sedge patterns when caddis hatch late in the evening in early to mid summer.
• Spinning: small bladed spinners such as a Veltic or Mepps. Soft baits are a good option in summer.
• Bait: not allowed.

Keeping a fish

Take any trout you keep home whole. Gutting or cleaning fish anywhere on the site is not allowed, because the lake is a drinking-water supply.

Rules and Safety

• Licence: a Fish & Game sports fish licence is required. Carry it while you fish and show it to a ranger if asked.
• Permit: fill in a free Water Access Permit at the reservoir kiosk before you go in. Follow any signs at the kiosk and gate on the day.
• Methods: fly and spin only. Mangatangi is not a coarse fishing water, and bait of any kind is banned.
• Where: only the signed areas of the dam face. The rest of the lake edge is out of bounds.
• Clean gear: gumboots and waders must be clean. Felt-soled waders are banned, and you must not carry water from another lake or river, including in a bait bucket.
• Limits: the bag and size limits are in the Auckland/Waikato section of the Fish & Game Anglers Notice. Check the current notice before you go.
• The dam: take care where you stand on the dam face, especially when it is wet, and keep children back from the water’s edge.

Getting There and Facilities

• Road: from State Highway 2, Fish & Game’s directions turn onto Mangatangi Road, then Kaiaua Road, then Workman Road, which leads to the dam.
• Walking in: drive-up access has been restricted since at least 2020, and anglers walk up the dam access road.
• The other reservoir: the lake to the west has its own guide: Mangatāwhiri Reservoir fishing. The rules there are the same, and its trout are wild fish.
• Bring everything: there is nowhere to buy gear at the reservoir. Buy your licence online and your flies and lures in town before you set out.

Useful Links

Mangatangi Reservoir: Common Questions

Do I need a permit to fish Mangatangi Reservoir?
Yes. Fill in a free Water Access Permit at the kiosk, and carry a Fish & Game licence as well.

Can I use bait at Mangatangi?
No. Only flies and artificial lures are allowed, and Mangatangi is not a coarse fishing water.

Where can I fish at Mangatangi Reservoir?
Only from the signed areas of the dam face. There is no fishing from the rest of the shoreline.

What fish are in Mangatangi Reservoir?
Rainbow trout, wild fish topped up with hatchery releases. Tench, perch and rudd are also present.

How do I get to Mangatangi Reservoir?
From State Highway 2, take Mangatangi Road, Kaiaua Road and then Workman Road. Walk the last part up the dam access road.

Can I clean my catch at the lake?
No. It is a drinking-water supply, so take fish home whole.

When is Mangatangi open for fishing?
All year, for fly and spin fishing.

Spotted something incorrect on this page? Let us know.