Bear Lake Watch SplashBack

 

Snowmelt is Here! May 7, 2025

The month of April was not a good month for Precipitation in the Upper Bear Basin. We only got 47% of the average precipitation. And the early snowmelt was about 50% more than average. The Basin has recovered somewhat in the past 5 days however. Precipitation was about 130% of average for the first 5 days of May. Below, the graph on the left shows the Snow Water Equivalent (SWE) for the Upper Bear as of May 7, 2025. The SWE was about 67% of average at that time. You will also notice the SWE is declining a bit faster than average. Precipitation however was 100% of average, having benefited from the rain the past 5 days. Soil moisture has remained good at about 100% of average at both 8 in and 20 in below the surface.

The reservoirs of the Bear Basin are 70%-105% of capacity. Bear Lake water level was 5919.24ft on yesterday, which is about 78% of capacity.

The streamflow forecasts as of May1st are down from the April 1st forecasts...a reflection of the lack of rain in April probably. That said, the chart on the left below is total streamflow forecast from the NCRS for the Bear River. For Stewart Dam the April-July forecast is only 89 thousand acre feet (kaf) down from 165 kaf on April 1st. Note that all points on the Bear River have forecasts for streamflow below the long term average. The top chart on the right below is from the Colorado River Basin Forecast Center (CRBFC) which uses a different total streamflow forecast model from NRCS. The chart shown is for the forecast total flow at Stewart Dam, just upstream from Rainbow Canal inflow to Mud Lake. This forecast shows a 50:50 probability of 96 kaf of total flow for this spring, down from 136 kaf in April. CBRFC forecast for peak streamflow just upstream of Stewart Dam is about 1455 cfs which is higher than last months forecast but sill only 68% of average. The bottom graph on right is from Connely Baldwin and shows the inflow at Rainbow Canal this year compared to last year as well as the average inflow.

Connely Baldwin of RMP has revised his modeling projections for Bear Lake Water level on April 29th. Connely expects Bear Lake to peak in late May between 5920.4 ft! The spread between the best and the worst case is also more narrow this month as would be expected given the data available for forecasting is more mature. His graph and chart are below.

As always I want to thank the folks at NCRS, CBRFC, RMP and all the others who help me compile the Splashback.

BEAR LAKE WATER LEVEL May 7, 2025 5919.24 feet*