Ameren Illinois crews worked throughout Wednesday to set up a mobile substation on high ground, in case of a breach involving the levee protecting the town of Prairie du Rocher, located approximately four miles east of the Mississippi River in Randolph County. A breach would compromise a major Ameren Illinois substation in that area. As a precautionary measure, Ameren Illinois proactively set up a mobile substation on higher ground in town. Mobile substations sit on flatbed trailers and are used in emergency outage situations. Should a breach occur, the company can quickly de-energize the town’s substation and safely switch to the mobile substation to avoid any long-term outages due to flooding. Ameren Illinois has three mobile substations in the Metro East and 17 throughout its service territory.