With fluctuating temperatures and heavy precipitation, potholes open up in the streets. (Gabe Silverman/The Washington Post)

Winter is taking a savage toll on the streets, trails and pipes of Arlington County.

Almost 90 times between Jan. 18 and Feb. 20, a water main somewhere in the 27-square mile county broke, for an average of 2.1 breaks per day. The county spent $1 million plowing during the big Feb. 12-13 storm and used 3,500 tons of salt. Potholes have popped up throughout the county with alarming frequency; although 80 percent of them were fixed by Monday, more are sure to come.

In a wide-ranging report to the County Board Tuesday, Arlington’s chief of the water, sewer and streets bureau Harry Wang said the aging infrastructure and abnormally cold and snowy winter combined to make this a particularly difficult year.

Residents are noticing, and are using a new smartphone app to alert the county staff to issues from potholes to unplowed trails to missing signs. County manager Barbara Donnellan said 425 requests have come in since Feb. 3. Residents without a smartphone can also report problems online at http://topics.arlingtonva.us/reportproblem/

Bicyclists and pedestrians have been particularly vocal in the past year about uncleared trails in Arlington’s growing bike commuter and walking trail network, and Donnellan said the county prioritizes clearing primary and arterial routes first. Just under six miles of access points to schools and Metro stations were cleared this month, and another 12 miles of the Custis, Lower Bluemont, Virginia Highlands, Washington & Old Dominion and Four Mile Run trails.

An unusually snowy winter has left behind an obstacle course of tire-eating, suspension-twisting potholes. What causes good roads to go so bad? Blame physics and the area’s up-and-down temperatures. (Sohail Al-Jamea/The Washington Post)

She told the board she would return in the future with a policy on how to clear the increasingly critical bike commuter routes.

Arlington residents are required to shovel their sidewalks within 24 hours after the snow stops falling, or within 36 hours if snowfall exceeds six inches. Donnellan said the county received 118 complaints this year of uncleared walks, and 39 property owners were notified of the ordinance. All of them complied after being notified, she said, so no tickets were issued.

Ninety percent of the water main breaks happened in pipes that are more than 55 years old, Wang said. The county has 525 miles of water mains beneath the streets and about nine miles of mains are replaced each year.