The North Marin Water District is proposing a rate increase for roughly 1,800 residents in West Marin to help pay for aging infrastructure and keep up with inflation. Bills will go up by an average of 6 percent, though a new rate structure will have individual customers pay closer to the actual cost of serving them. Depending on where you live, your bill could go down or up by as much as 14 percent. “We want to make sure the cost for customers is not unfair, and they’re not supplementing anyone else. It’s a shift to make it more equitable,” said Julie Blue, the district’s auditor and controller. A hydraulic zone surcharge will apply to Olema, Inverness Park, Paradise Ranch Estates and homes in Bear Valley, to pay for the cost of pumping water. The threshold for water usage reaching a higher payment tier will also be lowered, so heavy users will begin paying more after using 250 gallons a day, rather than 400. A bimonthly charge based on the maximum flow of a customer’s water meter will be raised, allowing the district to generate more of its revenue from fixed costs and a small number of bulk users. For low users living near sea level, the bi-monthly bill will go from $103 to $104. For low users at a higher elevation, the bill will go from $105 to $119. Half of the proposed rate increase simply reflects the rising cost of doing business, while the rest will cover construction projects, which the water district projects will cost $4.5 million over the next six years. The most expensive project is the replacement of a 25,000-gallon redwood tank in Paradise Ranch Estates with a 125,00-gallon concrete tank this year. The district is also boring a second well on the Gallagher Ranch, outside of the salty influence of Tomales Bay that has inundated the well on the Coast Guard property, leading to high levels of salt in the water. The district aims to finish the project by the winter, when the salinity intrusion is at its worst. Looking five years into the future, the district forecasts more replacements of pipes, tanks and pumps across its system. In 2030, the district plans to replace its water treatment plant on the Coast Guard property at a cost of $4.8 million. The district’s system in West Marin includes 25 miles of pipeline, 13 tanks, seven pump stations, three wells and the water treatment plant for 783 customers. The new rate schedule will be presented at meetings on Feb. 23 and March 16, and on June 22 the board will vote to enact the new rates on Oct. 1. To participate, visit nmwd.com.