Which decision caused the SWP pumping operations to shut down in 2007?

The Wanger Decision is the correct choice because it refers to a ruling by U.S. District Judge Oliver W. Wanger in 2007 that significantly impacted water pumping operations in California's State Water Project (SWP). This decision was made to protect threatened fish species, particularly the delta smelt, by enforcing stricter regulations on water pumping from the Sacramento-San Joaquin River Delta. The ruling aimed to address ecological concerns and led to reductions in water exports from the delta to agricultural and urban areas, thereby causing SWP operations to be curtailed.

In this context, the other options do not represent key judicial rulings that directly caused the SWP to shut down. The Paterno Ruling, for example, pertains to different legal issues in water management, and while the DWR Settlement and Delta Vision Agreement involve frameworks for water management and ecological sustainability, they were not direct decisions that led to the immediate suspension of pumping operations in that year.