The landslip at noon on Saturday caused a 3km-long, 20m-deep lake to form upstream of the slip and the Department of Conservation has been forced to close the Dart Valley Track between Daleys Flat Hut and Bedford Stream.
Doc Wakatipu partnerships ranger Chris Hankin said there would be variability in the river flow and the advice from GNS Science staff was the slip activity could continue for years but not at the weekend's scale.
''It hasn't stopped altogether.''
The new route would have to be ''well away'' from the slip area and, once a route had been identified, costs would be looked at. Construction of a detour was likely to take some time.
A statement from Doc on Monday said many sections of the track were either underwater or undercut and had fallen away, therefore tramping the complete Rees-Dart circuit was not feasible.
Trampers could still walk the Rees Valley to Dart and Daleys Flat Huts but would need to return the way they came or exit via the Matukituki Valley.
From the Dart Valley road end, people could still walk from Chinamans Bluff to as far as Bedford Stream before returning.
Dart River Jet resumed trips on Monday afternoon after operation was suspended following the slip.
The Otago Daily Times reported yesterday that GNS staff considered there was no immediate danger of a large volume of water being suddenly released down the Dart River below the dam produced by the landslip and the Dart River was no longer blocked.
Mr Hankin said the situation remained the same but was not assessed yesterday due to poor weather conditions.