The value of snow in our watershed

The value of snow in our watershed

Living in a mountain town, snow plays a major role in our lives. Winter in north Idaho brings a large shift to our community as we all turn our attention to the snow-covered mountains surrounding our town. However, as we begin to witness how human-driven climate change is affecting the regularity of our seasons and our snowpack around the globe, many folks are worried about the future of our natural resources and the downstream impacts it will bring

In Sandpoint, we sit next to the largest lake in Idaho and the fifth deepest lake in the nation. We are surrounded by tall mountains that collect snow in the winter and feed streams throughout the summer, acting as natural reservoirs. Our community is tightly connected to our watershed and humans have utilized it as an essential resource for thousands of years. Water scarcity in our area has rarely been an issue and we are incredibly fortunate for that. 

Skiing at Schweitzer Mountain Resort with Lake Pend Oreille in the background. Source: Schweitzer Facebook

Snowpack is vital to our waterways as well as our communities, especially in the western US. But the winters are getting warmer and spring is coming earlier (USGS 2005). Snowfall is decreasing around the world with rising air temperatures and more precipitation falling as rain instead of snow. And according to a study from 2010, average snowmelt in Idaho used to be in mid-June, but now is in late May (Kunkel and Pierce). What does this mean for our watershed?

There are many factors that can affect the amount of snow that accumulates, such as the soil conditions, surrounding vegetation, air temperature, and geography. In addition, the makeup of the snowpack, such as the texture and density of the snow, relates to how much water runs off the mountains and when. Snow water equivalent (SWE) is used to describe how much liquid water is held within a volume of snow. Snow scientists, hydrologists, and resource management agencies use this measurement to determine if our current snowpack levels are below normal, around normal, or above normal levels compared to previous years. At the beginning of March in 2022, we are below average SWE in the Idaho Panhandle (Figure 1). 

Figure 1. Idaho SNOTEL Snow Water Equivalent (SWE) percentage of normal as of March 1, 2022. Source: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/id/snow/products/?cid=nrcseprd1491224

Variation in snowpack and the timing of snowmelt is normal. This variability also depends on the basin in question. Scientists are currently working to develop large datasets that can help determine the future impacts of climate change in Idaho and our watersheds. Understanding how our water resources might be impacted in the coming years is incredibly important for sustaining our fisheries, recreational resources, economy, agriculture, and our drinking water

Snowmelt provides around 69% of the water in the Pend Oreille basin. This results in nearly 27 million acre-feet of runoff just from snow*. If we use this volume to determine the current annual value of usable water from snow, our basin is valued at over $890 million, making us the second most valuable basin in the western US after Puget Sound (Sturm et al. 2017). Losing the amount of snowpack we get each winter could not only drastically affect water as a natural resource for agriculture and human consumption, but could also drastically impact our local economy and the economies of downstream communities.

One example of downstream impacts includes the effect earlier snowmelt has on wildfires. According to University of Idaho professor John Abatzoglou, earlier snowmelt and drier conditions have extended the fire season in Idaho by roughly one by month since the 1980s. And over the past 50 years, fires have become larger and megafires, or extremely large fires, are more frequent. Fire is undoubtedly essential for forest health. But longer fire seasons and larger fires could make it harder for forests to recover and lead to fires in areas that don’t typically burn, such as riparian areas (Cooper 2018). 

The Trestle Creek Fire (pictured here on July 19, 2021) burned over 6,000 acres on the east side of Lake Pend Oreille. Source: https://inciweb.nwcg.gov/incident/photograph/7648/76/116312

Finally, it’s hard to understate the economic importance of snow. Snowmelt provides water for agriculture and human consumption for approximately one sixth of the world’s population. In addition, we all benefit from the climate services provided by snow – especially regarding the reflection of solar energy. These services have been valued at billions of dollars. Combined with the platform snow provides for outdoor recreation, the importance of snow in our lives has been valued on the order of trillions of dollars (Sturm, Goldstein, and Parr 2017).

If you’re interested in learning more, LPOW will be hosting a free Keeping up with the Waterkeeper event on March 3rd where we will be talking about snow in our watershed and its importance. This event will be hosted at the East Bonner County Library Community Room and will start at 5:30PM. All are welcome to attend in person or via Zoom, details will be posted on our social media and on our website. 

*An acre foot of water is equal to 326,000 gallons, or enough water to cover an acre of land one foot deep (approximately 1 football field).

Works Cited:

Cooper, L. (2018, June). Wildfire in the West. University of Idaho. Retrieved February 16, 2022, from https://www.uidaho.edu/news/climate-change/wildfire

Kunkel, Melvin & Pierce, J. (2010). Reconstructing snowmelt in Idaho’s watershed using historic streamflow records. Climatic Change. 98. 155-176. 10.1007/s10584-009-9651-x. 

Li, D., Wrzesien, M. L., Durand, M., Adam, J., & Lettenmaier, D. P. (2017). How much runoff originates as snow in the western United States, and how will that change in the future? Geophysical Research Letters.http://onlinelibrary.wiley.com/doi/10.1002/2017GL073551/full 

Lundquist, J. D. (2018), The value of snow, Eos, 99, https://doi.org/10.1029/2018EO109957. Published on 18 December 2018.

Sturm, M., Goldstein, M. A., & Parr, C. (2017). Water and life from snow: A trillion dollar science question. Water Resources Research. DOI: 10.1002/2017WR020840http://onlinelibrary.wiley.com/doi/10.1002/2017WR020840/full

Sturm, M., & et al. (n.d.). Water and Snow. Water and Snow. Retrieved February 16, 2022, from http://depts.washington.edu/sinter/basinSnow/

US Geological Survey. (2005, March). Changes in Streamflow Timing in the Western United States in Recent Decades From The National Streamflow Information Program. USGS. Retrieved February 16, 2022, from https://pubs.usgs.gov/fs/2005/3018/

US Geological Survey. (2019, June 12). Snowmelt Runoff and the Water Cycle | US Geological Survey. USGS. Retrieved February 16, 2022, from https://www.usgs.gov/special-topics/water-science-school/science/snowmelt-runoff-and-water-cycle#overview