Water rates will go up nine percent in 2019 as the City of Santa Monica embarks on several projects to wean itself off of imported water. City Council is expected to approve the rate hike at its Tuesday meeting. The average single-family home customer will pay about $4.33 more per month for water to fund the design of a larger, more efficient water treatment plant, the purchase of a new well and the cost of replacing the city’s aging water mains, said chief sustainability officer Dean Kubani. The rate increase will go into effect retroactively on Jan. 1.