Lawrence residents need to plan to use less natural gas this winter or face significant increases in monthly bills, Aquila Inc. officials said Wednesday.

The company, which serves 30,000 natural gas customers in Lawrence, said customers who had signed up for Aquila’s steady-payment program, called StreamLINE, would see an average increase of 74 percent on their monthly bills beginning in August.

George Minter, a spokesman with Kansas City, Mo.-based Aquila, said the average monthly payment for Kansas StreamLINE customers would increase from $50 to $87. There are about 3,300 Lawrence customers that are part of the program.

“We’re doing this now so people will know what is coming and so they can plan for it,” Minter said.

The StreamLINE program allows customers to have the same monthly bill based on their past gas usage. Minter said rates had to go up because the wholesale price of natural gas had increased significantly, from about $3 per thousand cubic feet at this time last year to about $5 per thousand cubic feet.

Customers who aren’t part of the StreamLINE program will face increases in their monthly bills, too, but it is more difficult to predict how large those increases will be, Minter said. He said the increase would depend on how much gas each customer used and the wholesale price of gas at that time.

In July, the average Kansas residential customers saw a 36 percent increase in their gas bills compared to July 2002. Minder said those increases likely would become larger with the onset of winter. Wholesale natural gas prices typically increase as colder weather arrives.

“We know that natural gas prices are probably going to go higher than they are today, but we just don’t know how much higher,” Minter said.

Natural gas prices have increased because natural gas supplies are at historically low levels, Minter said. Aquila estimates the amount of U.S. natural gas that is in storage is 25 percent below the level at this time last year.

A long, hot summer could lead to future price increases for natural gas, Minter said. That’s because more power plants are using natural gas to generate electricity. If the power plants use large amounts of natural gas this summer, it could create low supplies for the winter heating season.

Chip Blaser, development director for the Ballard Community Center, said the situation looked bad for low-income residents who have had trouble paying their natural gas bills in the past. The Ballard Center is a partner in a pair of programs that help people at or near the poverty level pay for utilities.

“The best thing we can tell people is to understand that it is coming and to the best of their ability, plan ahead to face those expenses,” Blaser said.

Aquila is recommending that customers look for ways to reduce their natural gas usage. Among the suggestions:

• Lower water heater temperature by a few degrees.
• Use cold water for much of the laundry.
• Check furnace filters monthly.
• Caulk and seal around windows.
• Add attic insulation.
• Install a programmable thermostat that automatically lowers temperatures in the house at night and when people aren’t at home.