Put water in the pack’s changing weight column

Weigh the container once

Use the same empty container weight for each scenario. If the cap, hose or filter is carried with it, weigh the set as it will go into the pack. That kit belongs in the base column, as described in base weight explained. The variable part is how much water you expect to have in it at each point.

The Pack ledger uses 1 kg per litre as a planning conversion. At the start, 2 L adds roughly 2 kg. If you reach a refill with 0.6 L and leave with 2.4 L, you have added 1.8 kg at that stop. No other part of the pack needs to move categories.

Compare the hardest carry with the start

The heaviest load can come after the start if a dry section follows a refill. Put the expected high carry in the ledger and compare it with the start. Keep other values fixed if the question is only about water. If the trip includes overnight food consumption, note that separately instead of assuming the starting food is still in the bag.

For a walking energy comparison, enter the two total pack masses into Loaded miles. Keep body mass, grade, time and speed fixed to isolate the load change. Read the Pandolf model limits before applying a result to a real uphill day. The calculation does not size anyone’s drinking supply.

Give each refill a source and a date

A blue line on a map is a lead to verify. Look for current information from the land manager and distinguish a tap, a stream and a seasonal seep. The source report note shows how to write the status without promoting a past observation to a certainty.

If a refill is uncertain, compare what happens if you skip it. A bigger carry affects weight and may change the timetable. A verified alternative route or shorter leg may make more sense than assuming you can use a source. Plan treatment appropriate to the water and current advisories.

Keep the weights beside the right legs

Use the route splitting note to locate each change. Put “leave the spring junction with 2.4 L if confirmed” in the relevant plan notes. Keep a separate line for the decision you will take if the source is dry or unavailable.

If you weigh the packed bag at home, compare the scale reading with the ledger before trusting a round number. The difference may be small, or it may reveal a forgotten container, stove fuel or wet item. When discussing an alternative with the group, give the carried mass and the source assumption together.

If the group shares water, keep a per-person ledger as well as the combined supply. The total for the party can stay the same while one person’s pack takes most of the additional weight. Record how the containers will be distributed.