This article links optimization algorithms in US southwestern water management to equitable apportionment and prior appropriation water policies in the 1950–1990 period. I argue that quantitative water law and algorithmic water management are coconstitutive historical processes, as they derive from the same formulation of settler colonial space and time—a practice I call settler computing. Settler computing clarifies how the settler theft of Indigenous natural resources is formalized within projects of data-driven resource management. I engage this history by reflecting on a major water planning project led by the Bureau of Reclamation called the Central Utah Project (CUP), which was formally enacted in 1956. When tech developers appropriated the Ute Indian Tribe of the Uintah and Ouray Reservation’s water and land during the development of CUP, this appropriation was simultaneously encoded in linear optimization frameworks.