New equipment designed to lengthen the life of snowplow blades meant that those blades didn't push down hard enough to cut through the snow and ice that caked Boulder's roadways during last weekend's snowstorm, city officials said Wednesday.

Many Boulder residents complained about the conditions of main streets -- including Arapahoe Avenue, Baseline Road, Broadway and 28th Street -- after the storm, which dropped 11.5 inches on the city by the time the snow stopped Sunday.

In response to complaints, city officials on Monday said the lower than expected temperatures meant that de-icer didn't work as well as it should have, but that they plowed and treated all the main streets according to their normal practices.

Residents pointed to clear streets in Lafayette and Louisville as they questioned that explanation. According to Boulder meteorologist Matt Kelsch, 4 to 6 inches of snow fell in Lafayette and 5 to 7 inches fell in Louisville over the weekend.

However, residents also found relatively clear streets on the University of Colorado campus, which saw the same snow totals as the rest of the city.

But on Wednesday, in response to follow-up questions, Boulder Public Works spokesman Nick Grossman said the city's drivers reported that their plows didn't seem to have enough downward pressure on them and that they weren't cutting the snow properly.

That problem was compounded by the large amount of snow and the cold temperatures, resulting in a layer of ice on many city streets, Grossman said.

Grossman said the city had plenty of de-icer on hand and used the same amounts throughout this storm as during similar storms.

Boulder has a policy of keeping at least 250 tons of de-icer in stock and having enough for two to three weeks worth of plowing in the coldest, darkest months of winter, Grossman said.

Boulder had more than that on hand Friday before the storm started, and the city just ordered another 600 tons to maintain supply levels, Grossman added.

The main issue appears to be how the plow blades were calibrated before the storm, Grossman said, and public works crews will make sure they are adjusted appropriately before the next snow storm.

Grossman said new equipment was installed before the 2013-2014 snow season. That equipment reduces the downward pressure on plow blades with the intent of lengthening their useful life. However, the equipment can be recalibrated to increase the downward pressure as necessary to deal with conditions.

Grossman said doing that may shorten blade life, but it's more important to Boulder's public works crews to remove snow and ice effectively.

"A lesson the city learned is to better calibrate the downward pressure of the plow blades so they are more effective, especially in colder weather," he said. "The cold temperatures and the amount of snow did allow the snow to become compacted more quickly and harder than we were expecting.

"The core function of the plow blade is to remove snow and ice, so that will be our priority."

Contact Camera Staff Writer Erica Meltzer at 303-473-1355, or