A week after a new majority seized control of the Central Basin Municipal Water District’s board and fired its embattled general manager, the results of Tuesday’s election could upend the fledgling regime.  … Central Basin Municipal Water District is a public water wholesaler with few of its own employees. It serves nearly 2 million people from 24 cities and unincorporated areas in southeast Los Angeles County, with its boundaries stretching from La Habra Heights in the east to Carson in the west and from Signal Hill in the south to Montebello in north. The board is made up of seven members, four of whom are elected and three of whom are appointed by the agency’s customers. The state Legislature forced the appointees on the agency following a scathing state audit that found questionable contract practices in 2016.