SIOUX CITY, Iowa (AP) — It’s been a tough winter for Sioux City’s infrastructure, with the city on track to see an increase in the number of water main breaks for the second year in a row. The Sioux City Journal reports that city had 39 breaks in the first nine weeks of the year, far more than in previous years.

The city’s underground utilities superintendent, Jon O’Brien, says deeper freezing and other soil conditions often contribute to main breaks. He says the number of breaks is hard to forecast. Sioux City has 474 miles (762 kilometers) of water mains and averaged around 22 main breaks per 100 miles last year. That’s below the estimated national average of 25 to 30 breaks per 100 miles.