Start with the flood map, its copy register and later margin notes. It is the source used to decide whether the line records a lost spill channel or a later copyist’s change; it is not the decision itself. The rule only works if the source describes conditions at the map room under Ferry House.
Known: the current file counts 39 map marks with a dated source note, compared with 42 in the prior window. Workers and residents submit accounts before the public hearing closes. The entries have dates and a named clerk.
Disputed: The line is visible on the surviving copy. The archive has not found a matching field survey or a named hand. One side emphasizes the posted total; the other points to a blue channel line appears on one copy but not the filed public sheet.
Why it matters: the decision determines which residents can rely on the service and which staff must carry out the change. The file does not settle that by itself.
Next: The Year fifth, high summer window 1 file remains open for its scheduled decision. The archive will publish the two copies with their later marks dated separately.
