Miss. Code Ann. § 51-9-176: Miss. Code Ann. § 51-9-176

At the request of a Mississippi municipality, county, other legal political subdivision of the state or a Mississippi state agency, federal agency, or under a declaration of a state of emergency or disaster by the Governor or the President of the United States, the officers of the Pearl River Valley Water Supply District Reservoir Police may render law enforcement services including search and rescue using Pearl River Valley Water Supply District Reservoir Police equipment. Officers of the Pearl River Valley Water Supply District Reservoir Police may also participate in joint multijurisdictional training exercises, multijurisdictional law enforcement operations and multijurisdictional search and rescue operations. The officers may exercise the law enforcement authority granted under Section 51-9-175 in the jurisdiction of the training, operation or emergency. The Pearl River Valley Water Supply District Reservoir Police, with the approval of the governing board, may enter into agreements with jurisdictions regarding the circumstances in which emergency assistance may be provided and administered. Unless otherwise directed by an agreement, officers will remain under the authority of the Pearl River Valley Water Supply District Reservoir Police Chief or to whomever and to what level of authority is delegated by the Pearl River Valley Water Supply District Reservoir Police Chief or by assignment through the National Incident Management System or by the stated declaration of disaster or emergency. The Pearl River Valley Water Supply District Reservoir Police may seek reimbursement for services and related expenses if available.