Lakes and rivers in Northern Idaho are beautiful and inspire thoughts of recreation on warm summer days. However, these surface waters are also critical to our water supply and rely on one major thing — snow!
The Coeur d’Alene-St. Joe Basin, which includes Coeur d’Alene Lake and the area that flows into it, receives about 60% of its water from snowmelt runoff.
Additionally, the dollar value of this snow that we rely on is estimated to be over $180 million per year. Because of this, it should come as no surprise that snow is one of the most valuable resources, especially here in the western United States.
As European settlers arrived in the West throughout the late 19th century, they realized that developing their society in this region would require supplemental water supply and management.
Across the West, pioneers rose to the challenge by building reservoirs, stream diversions and canals. Still, conflicting demands and increasing pressure on the water supply required more informed decision-making.
To address this, Dr. James E. Church, a professor at the University of Nevada, Reno, began measuring the snowpack on Mount Rose, Nev., in 1906.
These snow measurements resulted in his successful forecasting of the annual rise in the surface of Lake Tahoe and the corresponding outflow of the Truckee River — a breakthrough in water management.
This development allowed for effective lake discharge management, simultaneously preventing hazardous flooding and enabling regulators to meet downstream water demands.
Today, the Natural Resources Conservation Service (NRCS) and the National Water and Climate Center (NWCC) lead snow measurement and water supply forecasting as Snow Survey programs across the western United States, including the beautiful Coeur d’Alene-St. Joe Basin.
Over 100 years later, hydrologists at the NRCS Idaho Snow Survey still use similar tools to measure what Church was after — the snow water equivalent (SWE).
SWE is the depth of water that would cover the ground if the snow cover was in a liquid state.
While snow depth is what most people may think of when measuring snow, SWE is more critical because it is more predictive of how much water will be available for runoff into our lakes and rivers.
Not only does our snowpack vary annually, but it also varies significantly across the landscape of Idaho.
The Coeur d’Alene-St. Joe Basin is 3,840 square miles and ranges in elevation from around 2,100 to 7,000 feet, which can lead to widely varying snowpack conditions.
The NRCS Idaho Snow Survey operates a network of automated data collection sites called SNOTEL (SNOw TELemetry), which records observations of snowpack conditions across the state in realtime.
The Coeur d’Alene-St. Joe Basin is home to seven SNOTEL sites. Additionally, the basin has six Snow Courses, where surveyors manually measure the snowpack using similar tools as Church.
These tools and methods, combined with close collaboration between various agencies and communities, help to manage our most valuable natural resource: water!
Whether you are an agricultural producer, skier, angler, boater, hunter, researcher, water manager or an interested community member, the NRCS Idaho Snow Survey has resources and data available for you.
You can access this information through the NRCS Idaho Snow Survey website or the NRCS interactive map, where you can see realtime conditions across the western United States.
By PETER YOUNGBLOOD