The dollar signs are starting to emerge as city commissioners put together the city’s 2016 budget, and significant water and sewer rate increases are among some of the new costs Lawrence residents should expect.

Commissioners at a Tuesday afternoon budget study session were told about likely water and sewer rate increases that would total about $8 per month over the next two years for an average water user and closer to about $25 per month for homeowners who do a lot of lawn watering.

Leaders with the city’s Utilities Department are recommending commissioners this summer approve two years worth of rate increases, which would complete a five-year plan to raise rates to pay for major projects such as upgrades to the city’s water plants and construction of a new sewage treatment plant south of the Wakarusa River.

City commissioners did not take any action on the rate request but will be asked to vote on the requests in coming weeks. Several commissioners said they understood the need for the rate increases but noted they want to look at programs the city could create to help low-income residents better absorb the rate increases.

“Increases like this can compound with other increases, and it becomes hard for a low-income resident to continue paying the rent,” said Mayor Jeremy Farmer, also noting the pending increase in sales taxes approved recently by state lawmakers.

Farmer said some cities — he noted Detroit — have programs that allow residents to make donations that help low-income families pay their water bills. Currently, the city does not run any such program, but rather relies on private social service agencies to provide such assistance.

As proposed, the rates increases would be slightly different for different types of users. Here’s a look at how they would impact some common water and sewer users:

• Residents who use an average of 4,000 gallons of water per month would see their monthly water and sewer bills increase by $3.64 per month — 6.6 percent — in 2016 and another $4.40 per month — or 7.4 percent — in 2017.

• Residents who use an average of 15,000 gallons per month — which is more typical of a homeowner that operates a lawn sprinkler system — would see larger increases. The proposal calls for $12.11 per month — 7.2 percent — in 2016 and another $14.85 per month — 8.2 percent — in 2017.

• An apartment dweller who uses 4,000 gallons per month would see a rate increase of $2.76 — 5.6 percent — in 2016 and another $3.84 per month — 7.4 percent — in 2017.

• A commercial business that uses 100,000 gallons per moth would see a monthly rate increase of $77.71 — 8.1 percent — in 2016, and another $83.75 — 8.1 percent — in 2017.

Commissioner Leslie Soden said she wanted to look at future changes to the city’s rate structure that would do more to encourage residents to conserve their water usage. That could be a system that would charge higher per-gallon rates to users who use large amounts of water, especially to water their grass.

“If we could encourage the use of low-water-usage type of grasses in yards, that would be very beneficial, but I realize that would be a really big project,” Soden said.

Leaders with the Utilities Department said it may be difficult to make rate changes during the next two years, but the city is planning to study its rate structure to create a new series of rates beginning in 2018. Mike Lawless, deputy director of utilities, said some communities have adopted rate strategies that determine an average of how much water a household uses during the winter months. It then charges a higher rate if the household uses a significantly larger amount of water during the summer months. That’s one way to target lawn irrigators but also will catch other water users as well.

“If you grow a vegetable garden, you would be impacted by that type of system,” said Dave Wagner, the city’s director of utilities. “It doesn’t recognize the difference between watering roses and potatoes.”

Among other budget issues discussed Tuesday, commissioners:

• Said they would consider increasing the amount of general fund dollars they provide to social service agencies. Commissioners received from the Social Services Funding Advisory Board a recommended 7.5 percent decrease — or about $40,000 — in the amount of general fund social service agency funding. Commissioners said they wanted to receive another round of revenue projections in the next several weeks before deciding on social service funding levels.

• Heard a request from the Lawrence Public Library to increase its funding for 2016 by $199,330, or about 5.6 percent more than its 2015 budget. About 75 percent of the request is related to increases in wages and personnel costs for library employees. The library is proposing a 2 percent wage increase for its employees and also is seeking to create a new full-time position to manage the library’s sound studio and two other full-time positions to help serve the larger crowds that are visiting the expanded library.

• Received information that the city’s solid waste division is not planning any increase in trash rates in 2016. Department leaders said they wanted to see a full year of activity from the city’s curbside recycling program before considering future rate increases.