Riverside’s utility hopes to make $3.5 million this year on a deal to sell water to a nearby water district. Last year, the city sold a small amount to customers of the Western Municipal Water District. Officials with Riverside Public Utilities and Western say the deal benefits both agencies’ customers by helping Riverside make up lost revenue and saving Western money. Under the pact, Riverside would sell up to 5,000 acre-feet of water to Western between September and February 2017. An acre-foot is about enough water to serve two households for a year.