What DOC resources are actually worth using before you go?
DOC’s website (doc.govt.nz) carries live track status information on each specific park and track page: closures, storm damage, and hazard alerts that get updated faster than any third-party blog. DOC publishes these alerts per-track rather than on one central alerts hub, so the practical approach is to check the specific track’s own page, not search for a single unified status URL.
The same site runs the centralised booking system for Great Walks, huts, campsites and lodges (at bookings.doc.govt.nz), which is where you book Milford Track season passes or a Waikaremoana hut, and where you can set a notification alert if a booking becomes available after a cancellation. Hump Ridge Track is the one exception: its bookings run through the separate Hump Ridge Trust website, not DOC’s system, which trips people up if they assume all 11 Great Walks book the same way.