This essay revisits the Moscow Canal and explores its waters as the matter that bears witness to the violence experienced by human and nonhuman actors during the waterway’s construction between 1932 and 1937. By attending to the canal’s flow, it argues that water can operate as an alternative archive, expands the limits of what is currently considered unarchivable, and contributes several artifacts to more conventional forms of documentation. Using the operative concept of material witness developed by the artist-researcher Susan Schuppli, the essay investigates the artificial flow and analyzes patterns of its organization and operation as processes that register, disclose, and preserve the residues of violence that remain present underwater yet missing from the Moscow Canal narrative, inviting renarration of the histories produced by the reductive archival structures.