April 16, 2021

Colorado Workgroup Plans to Take Snow Data Collection to New Heights

The Colorado Water Conservation Board has named Northern Water a grant recipient from the Water Supply Reserve Fund for the Colorado Airborne Snow Observatory (ASO) Expansion Plan. This funding will be used to support a workgroup that will investigate the benefits of regular ASO flights to all Colorado water stakeholders.  

What is the Airborne Snow Observatory?

ASO is an advanced method of measuring snow depth and retrieving snow water equivalent. SNOTEL (Snow Telemetry) sites are currently used to collect this data and will continue to be valuable if and when ASO is more widespread. However, SNOTEL locations are limited and ASO would provide high-resolution data across entire basins. The ASO method, a NASA-developed technology, takes flight over large river basins and combines lidar, imaging spectrometer sensors and snow dynamic models to obtain measurements. ASO provides unprecedented — detailed, accurate and decision-supporting — data. 

ASO has been used in Colorado Before – with Success
Mountain top peaks with snow in Never Summer Range
Never Summer snowpack

In 2019, a flight series took place over the Blue River watershed, an important source for Denver Water. At the time, the SNOTEL stations reported that the sites within the watershed had melted out. However, ASO data revealed that there were 115,000 acre-feet of water remaining at high elevation. Upon receiving this information, Denver Water and Colorado River operators reduced levels in Dillon Reservoir to account for this unexpected runoff. Having this information, adjusting outflows and coordinating operations likely prevented downstream flooding and water loss.  

Coordinating ASO flights is not uncommon for water stakeholders in Colorado. For some time, these flights have provided valuable information later in the snow season when SNOTEL sites no longer provide accurate measurements of snow water equivalent. While the flights provide valuable information, they are expensive. With Denver Water taking the lead, several stakeholders, including Northern Water, have come together to discuss the efficiencies that would come from collaboratively funding ASO. The Water Supply Reserve Fund grant received will allow a workgroup to continue exploring the idea and formulating a plan.  

What’s Next?

The workgroup will focus on four main goals: 

  1. Basin flight planning, data collection and analysis 
  1. Gathering information on operational and planning benefits to stakeholders 
  1. Reviewing sustainable funding mechanisms 
  1. Reviewing governance structures of similar programs

Expanding ASO data collection throughout the state would provide a proven method to maximize the use of water supplies. Accurate snow water equivalent data will enable water managers to make better informed operational decisions, maximize safe reservoir storage levels, improve flood control preparations and provide accurate snowmelt and runoff information (quantity and timing).  

The ultimate goal: develop a collaborative plan to fund ASO flights across Colorado and take snow data collection to new heights.   

Learn more about the Colorado Airborne Snow Observatory at www.coloradoasoplan.org.