Two Boise State researchers warn that climate change could lead to "a significant decrease to the aquifer for the Boise and Spokane rivers' basins, resulting in an even broader impact to Treasure Valley residents who depend on the basins for drinking and irrigation.
“Essentially, this is going to shift the hydrology of the basin and that is going to affect wildlife, wildfire possibilities," said Boise State civil engineer researcher Venkataramana Sridha, who authored the study with colleague Xin Jin. "I would also say that it is going to have an effect on the flows of the river, and depending on how it is managed, for rafters and recreational purposes.”
Sridhar and Jin concluded that between 2010 and 2060, the Treasure Valley's changing climate patterns could increase temperatures two to four degrees Fahrenheit. Additionally, precipitation rates are expected to change, ranging anywhere from a 3 percent decrease to a 36 percent increase. The changes would dramatically impact snow-melt timing, stream flows and aquifer recharge sequences.
“It is going to have an effect on hydrology of the basin scale as well, and then it will also have an effect on the recharge,” said Sridhar. “So we are talking about increased snow in the form of rain, which will probably have less time for infiltration which will mean less time for recharge.”
If snow-melt occurs earlier than usual, Sridhar said the Treasure Valley could see less moisture in the later part of the year and drier soil in the later parts of the growing season. This, in turn, would increase the potential for wildfire and drought.
Although the new research projected a 50-year time frame for climate change and its effects, Sridhar said that the changes in climate are already affecting the Treasure Valley.
“I think we are already seeing that shift occurring right now,” Sridhar told Citydesk. “The last few years, the melt was actually happening faster and earlier, even if you think of what we saw this year and probably even last. We had more flows in the early part of the season and they had to really effectively manage the water to keep it at a safe level. So we are seeing the effect already and it might really be adding to this in the future.”
Sridhar said that this snow melt shift of about two to three weeks earlier, with the peak coming in April instead of May, will mean less time for water storage resulting in a possible shortage.
“Effective management will be the key instrument to manage this scenario,” Sridhar said.
Sridhar and Jin’s study results can be found online in The Journal of the American Water Resources Association.