In an effort to support its new brackish desalination plant and other improvements, water rates in Antioch are set to rise after the city council on Tuesday approved a new five-year plan. Starting May 1, the cost of water will increase as much as 7% annually for a single-family home and then potentially rise further over a five-year period. The Antioch City Council approved the rate jump in a 4-1 vote. Councilmember Tamisha Torres-Walker was the lone no vote. … According to a staff report, the new brackish desalination plant that is expected to start operating within the next few months requires increased personnel and maintenance costs.