According to a study by the city’s Office of Public Accountability/Ratepayer Advocate, it could be as little as $1.73 per month. But project opponent cite an independent study concluding the cost could be more than $7 a month. The California Water Fix is an $18 billion to $26 billion proposal pending in the state legislature to build giant underground tunnels to route Sacramento River water under the Sacramento-San Joaquin Delta. The water would flow into the California Aqueduct for use by farms and homes to the south.