RBC | A new analysis of 38 years of SNOTEL data and more than a century of USGS streamflow records compiled by local science educator Dr. Bob Dorsett shows clear signs that the headwaters of the White River are warming, drying, and running off earlier each spring—conditions that have profound implications for ranchers, municipal water providers, wildlife managers and anyone who depends on the river.
Dorsett’s 2025 Climate Trends report draws on measurements from the Burro Mountain and Ripple Creek SNOTEL sites, as well as discharge records from the USGS gauging station near Meeker dating back to 1910. The report points to consistent long-term shifts: higher temperatures, reduced precipitation, earlier melt-out, and dramatically lower late-summer river flows.
“These patterns are striking, and they match what we’re seeing across the American Southwest,” Dorsett notes in the summary.
Warming Temperatures in the Flat Tops
Data from the Burro Mountain SNOTEL shows that average daily temperatures have climbed sharply since the late 1980s. The increase is especially pronounced in mid-winter and late summer—two periods critical for snowpack accumulation and for maintaining river flow. statistical comparison of the 1987–91 water years versus 2021–25 shows a highly significant warming trend (p << 0.001), with more than 11 standard deviations separating the two periods.
Less Precipitation and a Thinner Snowpack
Annual precipitation at Burro Mountain is also declining, with a statistically significant downward trend since 1981. The drop is visible in both year-to-year totals and long-term trendlines.
Snow water equivalent (SWE), the measure of how much water the snowpack contains, showed considerable variability from year to year, but the timing of melt-out is shifting earlier. In 2025, both SWE and total precipitation fell well below the 30-year median, a pattern consistent with ongoing drought.
Earlier Runoff and Lower Peak Flows
The White River historically peaked in early June. Today, peak flow is occurring earlier and at lower volumes. Mann-Kendall trend tests indicate a long-term decline in both total annual runoff and peak discharge:
Total runoff has dropped about 70,000 acre-feet since 1910, roughly a 14% loss.
Peak flows are now about 500 cfs lower on average than they were a century ago.
Earlier melt shows up in higher April flows and decreased flow in late May and early June, the historical peak.
Late-Summer Flows Are Dropping Fast
Of all the trends identified in the report, the most dramatic is the decline in September river flows. The long-term record shows a steep reduction in base flows at the end of the irrigation season.
The statistical signal is strong: Mann-Kendall Z = –5.03 (p < 0.001).
At this rate, Dorsett writes, the White River could run dry in some stretches during September before the end of the century—an outcome previously considered unthinkable.
Low September flows mean warmer water, more algae growth, reduced habitat for trout and other species, and greater strain on irrigation and municipal supply systems.
Wildfire Impacts Still Visible
The aftermath of the Elk Fire continues to shape the river corridor. Ash and debris washed downstream during monsoon storms, smothering benthic habitat and reducing the number of macroinvertebrate families found in a September 2025 survey of aquatic insects.
Sites below the burn scar contained far fewer insect taxa, especially among sensitive groups like mayflies, stoneflies and caddisflies.
The Lee Fire likely produced similar impacts downstream of Meeker.
Entering a New Water Year in Persistent Drought
The report ends with the USDA Drought Monitor map from September 2025, showing Rio Blanco County in moderate to severe drought. Higher temperatures and declining snowpack are leaving soils drier, which in turn absorb more spring runoff before it ever reaches the river channel.
Why This Matters for the White River Valley
For agricultural producers, earlier runoff can mean:
• Less water available when hay fields need it most
• Shorter irrigation seasons
• Reduced recharge of ponds and alluvial wells
For fish and wildlife managers:
• Higher water temperatures stress trout
• Low flows favor algae blooms
• Habitat complexity declines without strong peak flows
For towns and homeowners:
• Declining late-summer flows increase pressure on municipal water systems
• Drought cycles become harder to escape
The report doesn’t prescribe policy recommendations, but it provides a data-rich foundation for ranchers, local governments, water districts and land managers as they plan for the future.
Dorsett’s takeaway is simple: “The river is changing. The trends are long-term and unmistakable. Understanding them is the first step toward adapting.”
Read the full report at https://www.theheraldtimes.com/wp-content/uploads/2025/12/ClimateTrendsSummaryData_2025_PDF.pdf
This doesn’t look like December in Colorado. A week after the Parade of Lights, what little snow was available for snowball fights is long gone, marking another December of unusually warm temperatures and minimal precipitation. NIKI TURNER PHOTO
