Don't Wait to Feed Water
The 2020 version of the United States FARM minimum standards for calf care call for water feeding for newborn calves by day 3.
Recent research looked at the question of how early water feeding makes a difference in the digestive system of very young calves. The work done at Iowa State Univ. compared the species of bacteria present in the gut between calves offer water at birth and those offered water at 17 days.
Digestibility was better in the calves fed water at birth compared to those that waited until 17 days for water feeding. Additionally, even out to 5 months of age early-water fed calves compared to those with delayed water feeding had a 24 pound (11kg) growth advantage (440 lbs. vs. 416 lbs, 199.5kg vs 188.7kg)
With my own calves I fed 1 quart (about 1 liter) of fresh water after both morning and evening feeding. It's hard to recall exactly, but if my memory is accurate some of the calves were regularly consuming an observable volume of water by the end of the first week.