"This energy emergency declaration is necessary to ensure that petroleum supplies will remain sufficient and to assure the health, safety and welfare of Michigan residents and visitors," Michigan Gov. Rick Snyder said in a statement.
Snyder's office said the closure of the pipeline means gasoline and diesel carriers needs to find new ways of getting products into his state.
Through an executive order, he suspended state and federal regulations related to how long drivers transporting gasoline and other fuel products can stay on the road so fuel deliveries are ensured.
The West Shore pipeline was closed last week after federal authorities reported the release of 1,000 barrels of unleaded gasoline. The Detroit News reports the pipeline has since been repaired and retail gasoline stations in the state's Upper Peninsula were largely unaware of the disruption.
Retail gasoline prices in the state, as indicated by gasbuddy.com, appear unaffected by the disruption. The West Shore pipeline has a 70,000 barrel-per-day capacity.
Snyder's measure "remains in effect until it is rescinded or until Aug. 7 at 11:59 p.m., whichever first occurs."