Snowpack Expected to Improve Drought Conditions

As spring slowly approaches in Central Oregon, winter snowpack and precipitation levels can help predict drought conditions in the months ahead. Deschutes Basin Watermaster Jeremy Giffin sees promise, noting that the state of our reservoirs is the best start to the irrigation season in the last six years.

As of March 18, the Oregon SNOTEL snow/precipitation update report showed that the Upper Deschutes basin was at 112% of average for the snow water equivalent, which is the water content in the snow, and 111% of average in total precipitation. “Things are definitely looking up,” said Giffin.

Ski resort Mt. Bachelor has received 325 total inches of snow this season, with a base depth of 113 inches. Additionally, Wickiup Reservoir , the biggest in the Deschutes River basin, was 74% full as of March 18. Climate experts anticipate the reservoir to be just over 75% full at the start of the irrigation season. “That’s good news for all of the irrigation districts that rely on stored water.”

In the early winter months, climate experts predicted a strong El Niño climate pattern resulting in warmer, drier winter conditions in Oregon. Despite the warmer climate pattern, Oregon saw a promising shift in its winter weather in January, yielding better conditions than expected.

“We were in a pretty rough spot up until the first of the year,” said Giffin. “Then the snow and rain started and definitely improved our outlook for the 2024 irrigation season.”

While the area is above average for both snowpack and precipitation, it’s not a lot above average. Since the region has been below average for several years in a row, Central Oregon is still in a moderate drought right now, said Giffin.

“We are also coming off the heels of many years of prolonged drought, so I still anticipate there will be curtailment on irrigation withdrawals in the upcoming season.” That means some farmers — likely those junior water rights holders in the North Unit Irrigation District — could see irrigation water cut off earlier in the summer season.

According to Giffin, this year’s snowpack and precipitation levels really make a difference. Last year, Upper Deschutes had an above average snowpack. “That was good news for the ski resorts, however, we were behind on the overall precipitation. While our snowpack was looking good, it was only one part of the equation,” said Giffin.

Since we were missing the overall precipitation, the region didn’t really see a bounce in local area streams, rivers, reservoirs or aquifer, since it was just snowpack and it wasn’t significantly above average.

“This year, we’re looking a little better because we’re above average in both categories, so that should make a difference,” said Giffin. Since we are in the Deschutes Basin, which is groundwater fed, Giffin said there’s a lag time from when the snow melts to when it comes out of the springs that create the Deschutes River.

According to a Portland National Weather Service report, the Oregon Water Supply Outlook released on March 7 by the Portland National Weather Service, the reservoir storage for most irrigation reservoirs across the state is generally above average, with the exception of southwest Oregon.

The report also found that water supply forecasts for April through September runoff volume are the highest, relative to average in central and east-central Oregon. Another statistic mentioned that Central Oregon watersheds had a particularly above average observed streamflow.

“It’s still too early to tell what the snowpack is going to do for the upcoming natural flows of the streams – the flows without the reservoirs being involved – but I am anticipating an increase in flows over last year,” said Giffin.

This year’s precipitation and snowpack show a big improvement from 2023 and 2022, which resulted in harsh drought conditions. In April 2022, the Upper Deschutes received about 99% of the median yearly snowfall and the overall precipitation was 11% short of the median, resulting in a bigger water deficit.

Editor’s note: In response to the comment above about possible curtailment of water for farmers in the North Unit Irrigation District, Josh Bailey of NUID shared the following clarifying statement:

“NUID has many Habitat Conservation Plan (HCP) measures that we are required to meet during the irrigation season (April 1 through October 31). Some of the measures require specific flows in the Upper Deschutes River to be met, such as the following: ‘Flow at BENO gauge shall be no less than 1,300 CFS from July 1 through at least September 15.’ Because of this measure and others like it, NUID spreads out the available water to meet these requirements and will typically strive to deliver water continuously throughout the entire irrigation season. The exception to this rule was in 2021 and 2022 when the district had to shut down early due to a severe lack of storage and live flow in the Deschutes River. In both instances, NUID turned back on in September.”