Gwinnett County water and sewer rates will go up beginning Jan. 1 — and will continue to rise for the next decade.

The 2021 increase of 30 cents per 1,000 gallons of water used and 49 cents per 1,000 gallons of sewer are just the first of six increases planned between January and 2031.

The increases are needed because demand for growth is outpacing the county’s sewer capacity, said Lisa Willis, the deputy director over Gwinnett’s bond delivery program. Through early December, 39 development projects were approved in the county contingent on additional sewer capacity.

Gwinnett will take out $333 million in bonds in two sets to pay for a slew of projects that will be repaid through the rate increases. Pricing of the first, $190.6 million bond will happen this week. The second, $142.4 million bond won’t be priced until 2023.

By the end of the decade, water rates will be $1.38 higher per 1,000 gallons, sewer rates will go up by $2.27 per 1,000 gallons and a new sewer base rate of $2.50 will be added to every bill.

The expected cost to the average Gwinnett County resident will be bills that are $20.21 higher a month, by 2031. Still, Michael Lanfreschi, the water department’s director of finance and project controls, said he expects Gwinnett water bills to stay below those in Atlanta and DeKalb County ― both of which are operating under billion-dollar consent decrees with environmental regulators that require massive projects to fix those systems.

The county spent less than $20 million a year on rehabbing and replacing pipes for most years between 2010 and 2018, but projections anticipate replacement expenditures will be closer to $40 million annually until at least 2026, as the county’s infrastructure ages.

Additionally, expansion plans for the county’s water and sewer system mean additional spending — in 2022 and 2024, for example, plans call for improvements that will bring total spending on the system above $100 million.

The improvements include new water lines and the expansion of water treatment facilities, pump stations and the county’s sewer system, among other projects.

“This is a big program for us,” said Tyler Richards, director of the county’s department of water resources. “If you can get ahead of it, you can do it a lot more cost effectively ... We’re looking ahead.”

The projects, Richards said, will help prepare the county’s infrastructure for more dense growth in the future.

Friday, leaders paid homage to a water visionary in the county, former commission chairman Wayne Mason. It was Mason who sought and received permission to pull water from Lake Lanier, and outgoing commission chairman Charlotte Nash said his vision had set the county up for success.

“What a difference leadership makes,” Nash said. “We all benefit even today from that. ... I know my time in office would have been totally different if you had not laid down the foundation.”

The county named its water supply intake facility in honor of Mason. He called the effort to get access to the lake “a gamble,” but said “we had to have it.”

“My theory was whoever controlled the water would control the destiny of the area,” he said. “If you don’t have that water, you don’t have anything. There’s no replacement for it.”