The National Hydropower Association (NHA) awarded Snohomish County Public Utility District (PUD) with the Outstanding Stewards of America’s Waters (OSAW) Award in the category of Operational Excellence at Clean Currents 2025 in Pittsburgh, Pennsylvania.

The OSAW Awards honor deserving organizations in the hydropower and marine energy industry for projects that exhibit exemplary operational, educational, historical, recreational, or environmental enhancement and stewardship; specifically, those which have performed stand-out work in up to three categories:

• Operational Excellence
• Public Education
• Recreational, Historical, and Environmental Enhancement

Through this platform, the industry has helped recognize its peers, calling attention to water power’s innovations, strategies, and developments while lending credence to the notion that by celebrating one, we recognize all.

The OSAW Award on display at Clean Currents 2025 (National Hydropower Association).

SNOHOMISH COUNTY PUD DEVELOPS HYRDOLOGIC MODELS, LEADING TO RECORD HIGH WATER SUPPLY

Snohomish County Public Utility District is the 12^th largest public utility in the United States and the second largest in Washington state, where it provides electric service to over 380,000 homes and businesses.

The Henry M. Jackson Hydroelectric Project – located on the Sultan River – is a multi-purpose facility owned and operated by Snohomish County PUD.

Located in one of the wettest parts of the U.S., Spada Lake – the Jackson Project’s reservoir – receives an annual precipitation of 162 inches. During January of 2020, a 48-inch monthly rainfall led to inflows that exceeded outflow capacity, which led to the reservoir spilling for the first time in decades; ultimately, the volume of water lost via the spillway could have translated into roughly 833 MW of generation per hour.

In response, Snohomish County PUD tasked themselves with developing a continuous improvement project to create a predictive hydrologic model for Spada Lake Reservoir, ensuring that daily elevations could be projected given inflow forecasts and scenario outflow volumes.

Taking the shape of two models – the Regression Model and Ensemble Streamflow Predictive (ESP) Model – these tools allow Snohomish County PUD to forecast reservoir elevations by utilizing both inflow and outflow data for power generation, fish flows, and water supply – the Henry M. Jackson Hydroelectric Project provides 75% of Snohomish County’s drinking water.

Implemented in 2024, the models have already demonstrated their effectiveness by improving forecasting accuracy; for instance, daily reservoir elevations for the first nine days of the forecast fell within the spread of the projected elevations >80% of the time.

Additionally, the use of these models allowed Snohomish County PUD to target higher elevations, as they had confidence that the models would help avoid spill, which was well illustrated in July 2024 when Spada Lake Reservoir was topped off within 0.3 feet from the spill elevation – the highest water surface elevation heading into summer in 40 years.

The Culmback Dam – part of the Jackson Hydroelectric Project (Snohomish County PUD).

FOR MORE INFORMATION

To learn more about Snohomish County PUD’s OSAW Award winning work, check out the video HERE.

To learn more about the OSAW Awards, click HERE.