Residents already pay the highest rates in Sonoma County, according to the Santa Rosa Press Democrat.
The increase would be about 6 percent over the next two years, smaller than the 9 percent annual spikes seen over the past decade.
The proposed increase would also target customers who conserve water: Most of the increase is in the fixed portion of the bill that everyone pays regardless of water use.
The average bill is expected to go up from the current $144 monthly to $153 monthly by 2013.
