After May 20, 1998, no referendum to allow the creation of a new emergency communications district within the boundaries of an existing emergency communications district shall take place without prior approval by the board. In the event that the board determines that such a creation is in the best interest of the public, and after holding a public hearing within the service area of the existing emergency communications district, the board may order that a referendum be held; provided, that such action shall not threaten the financial integrity or stability or the level or quality of 911 service of the existing emergency communications district.