Maybe short showers and low-flow toilets aren’t enough.

Starting this month, the city of Woodbury will begin asking residents why they use so much water, specifically targeting the top 20 percent or so of water users, in hopes of getting them to be more efficient.

Going into summer, water usage will be higher, Woodbury city engineer Klayton Eckles said, and that summertime water use itself has increased in recent years. As a result, the city could have to spend big on digging more wells and constructing more water towers.

But the city of Minneapolis isn’t in the same boat. The sole source of Minneapolis’ water is the consistent Mississippi River.

Minneapolis doesn’t have programs like Woodbury’s. Other cities, such as Bloomington, use Minneapolis water to supplement their own.

However, Nick Haig, a University graduate student who works in the Water Resources Center at the University, said it still requires money and resources to make every gallon of water used here potable.

“Conservation is conservation,” he said. “If people are wasting water, they’re wasting resources.”

Water usage tends to go up in summer months, in part because people like to have green lawns, Haig said.

During dry summers, some cities restrict water usage and ban residents from watering lawns. Minneapolis hasn’t imposed such a restriction since 1988.

The city, which produces an average of 70 million gallons of water per day, would likely impose restrictions if water usage surpassed treatment capacity.

Which parts of Minneapolis see a hefty amount of that water? The University is one of the Minneapolis Water Treatment & Distribution Services’ biggest customers.

Jerome Malmquist, director of energy management at the University, said the St. Paul and Minneapolis campuses will use an estimated 748 million gallons of water between them in the next fiscal year.

University Grounds Superintendent Lester Potts said water keeps grass green at the University during summer months, especially in high-use areas such as Northrop Mall.

“We don’t put on anymore than to keep it alive and healthy,” Potts said.

The grass at the University is watered about an inch a week, depending on weather, Potts said. Last summer there was a sustained drought so campus grass was watered more often.

Mike McDonald, the sports turf manager at the University, said most fields are watered two or three times a week.

Athletic fields require more water than other grassy areas, and McDonald said the Elizabeth Lyle Robbie Stadium in St. Paul requires the most because it’s a sand field. About 20,000 gallons douse that field each time it and the nearby Golf Institute are watered, he said.

But the University has done things to reduce its water consumption.

Malmquist said it takes about 67 million gallons of water to cool campus buildings year-round.

In 2007, the University cut consumption by 21 million gallons, the equivalent of about 50 Olympic-size swimming pools, by fine tuning the building-cooling process, he said.

Also, air compressors used to cool machinery on campus have been centralized, which Malmquist said has resulted in a significant water-use reduction.