The track is closed to prevent the spread of, and to protect against kauri dieback disease.
'Waitangi Falls is roughly a 45 minutes' drive away from Auckland City. The road surface is always sealed.
From Auckland travel north on the SH-1, then in Silverdale turn left into Kahikatea Flat Rd. Follow it until the intersection with SH-16, where you need to turn right and stay on the SH-16 for the next 9 km. A huge well-signposted car park is on your right (sign 'Omeru Pā Scenic Reserve'). There are toilets (2 min walk from the carpark) and a well-maintained picnic area available there (2-5 min walk).
A walking 20-minutes' return track leads from the parking to the base of the waterfall. From the parking, walk down the hill, then cross the stream via a footbridge, and turn left (opposite to Omeru Falls). Cross the clearing, then cross the stream again via one more footbridge, then walk along the stream. The last part of the track is always slippery; please be very careful, especially when you climb back from the falls. Return via the same track.
There is a super swimming spot at the base of the waterfall. In summer time lots of people enjoy swimming in cool water.
There are two more waterfalls which we highly recommend to visit as well - Waitangi Stream Cascade and Omeru Falls which require 15 minutes of further walk.'
- https://waterfalls.co.nz/waterfalls-by-region/80-new-zealand-waterfalls/north-island/auckland/89-waitangi-waterfall