ROCKY MOUNTAIN NATIONAL PARK, Colo. — Colorado communities that rely on water from dozens of glaciers and glacier features in Rocky Mountain National Park are concerned because the glaciers are shrinking as temperatures climb and winter snowfall becomes more uncertain.

Water from the Poudre, Colorado and Big Thompson rivers get meltwater from dozens of glaciers and glacier-like features around the park.

Park glaciers always vary in size depending on the seasons, but low snowfall amounts could keep them from being replenished. A change of a few degrees when temperatures are near the freezing point can turn snow into rain.

Between the 1990s and 2005, the glaciers started to shrink at an increasing rate. Rocky Mountain National Park’s glaciers were already small by comparison.

The biggest glacier in Rocky Mountain National Park is about 31 acres (13 hectares), according to a study in 2007.

A two-year study is underway to find out how the glaciers have changed in area and volume since 2005. Scientists will be using historic maps, climate records, photographs and measurements to better understand what’s happening.

Scientists will also study how glacier melt influences rivers, by measuring streamflow and collecting water samples to see how much water glaciers contribute to rivers, the Fort Collins Coloradoan reported (

Even a small loss in the snow and ice that feed rivers in northern Colorado could have a big effect on water supplies to Fort Collins and other nearby communities.

Paul McLaughlin, an ecologist at the park’s Continental Divide Research Learning Center, said changes in the amount of water and temperatures could also damage delicate river ecosystems.

Information from: Fort Collins Coloradoan,