A study that compared eight climate change scenarios to historic averages found that Ashland Creek flows would increase in spring but decrease in summer.

A study that compared eight climate change scenarios to historic averages found that Ashland Creek flows would increase in spring but decrease in summer.

Ashland, which relies mainly on Ashland Creek for its potable water, already faces summer water shortages in dry years. Shortages led to water curtailments in the summers of 2001 and 2009.

The climate change study looked at a range of temperature increases. For example, average temperatures in January could rise .54 degrees to 4.5 degrees. Average temperatures in July could rise 3.4 degrees to 10 degrees.

The climate change study by University of Washington Research Assistant Professor Alan Hamlet has important implications as city officials and the appointed Ashland Water Advisory Committee examine options for boosting the town's already limited water supplies.

"Climate change could affect our water supply dramatically," said Pieter Smeenk, a city of Ashland engineer tasked with helping the Water Advisory Committee. "It changes the timing of our supply. We'll have more supply, but earlier. It's going to be wetter in the late winter and spring."

Ashland Creek flows historically peak in mid-May and remain high until nearly the end of June before dropping off. Flows don't fall to extremely low levels of below 10 cubic feet of water per second until mid-August.

The average of the climate change scenarios predicts that flows will be higher beginning in December and will still peak in mid-May. But flows will plummet to below 10 cubic feet of water per second in mid-July.

Added rain and earlier snowmelt in the late winter and spring could spell trouble for Ashland because Reeder Reservoir, which stores water above Lithia Park, has limited capacity to store higher creek flows that come then, Smeenk said.

— Ashland Daily Tidings