Water consumption (US gallons)
Miele W1065/W1070:
https://www.manualslib.com/manual/353746/Miele-W-1065-Washing-Machine.html?page=42#manual
It seems by the 19XX series things were brought down to about 13 gallons per load (Cottons).
https://www.abt.com/product/13005/Miele-White-Novotronic-Washing-Machine-W1966.html
My W1070 has three water levels:
Low - Cottons/Permanent Press wash
Medium - Delicates wash
High - Woolens wash
All rinses are done at high level regardless of cycle chosen. One can decrease water usage by pressing the "one-half" button which rinses at lower levels. This button is also used for starching, and Miele suggests using enough product for five gallons of water.
Extended pre-soak is at high level. Normal pre-wash is at whatever level for cycle selected (Normal/Cottons, Permanent Press, Delicates). Pre-wash is disabled IIRC for Woolens.
The Miele can and will overflow sink when draining if water does not leave quick enough (clogged or slow sink filter for instance), after the wash cycle. It most surely will and faster the same for any of the rinses if one doesn't keep an eye on things.
OTOH there is never any danger of this happening from Lavamat. From wash and any of the rinses water barely reaches one-third up the way in sink. Only time there is the remote chance of overflow is if sink drain filter is clogged and water from two or more drain cycles cannot evacuate totally before another begins.
The Lavamat also will not top up with water once a certain level has been reached. Attempting to do so manually may trigger the overflow sensors, then machine will simply drain and throw a fault code. What the Lavamat will do is display a message indicating percentage of overload (120%, 130%, etc...)
The older Miele OTOH will stop and top up at any point in cycle it detects water level has dropped. If this occurs several minutes before draining, so be it. Machine also will turn on the thermostat to heat that newly added water if necessary.