La Niña Triggers Flooding and Swollen Rivers Across Southern Colorado
DEL NORTE, Colo. — The first signs of La Niña’s return are already making an impact across southern Colorado, where heavy rains and runoff from Hurricane Priscilla have caused swollen rivers, flash flooding risks, and highway closures, according to The Alamosa Citizen.
La Niña’s Arrival Through Remnants of Hurricane Priscilla
La Niña conditions strengthened this month as moisture from Hurricane Priscilla, which formed off Mexico’s Pacific coast, swept north into the San Juan Mountains and San Luis Valley. The storm system brought torrential rainfall, strong winds, and widespread flooding across the southwestern U.S., including La Plata and Archuleta counties.
“The San Juan River and its tributaries have been overwhelmed,” local emergency officials said, warning that runoff could continue for several days.
The storm’s remnants caused hundreds of homes to be evacuated around Vallecito Reservoir near Durango, while erosion and flooding forced the closure of Wolf Creek Pass over the weekend.
(Source: Alamosa Citizen)
San Luis Valley on Alert for Flash Flooding
Emergency management teams across the six-county San Luis Valley remain on alert as more rainfall is forecast for the eastern San Juan region, where 3 to 4 additional inches could fall this week.
When the ground is hardened from years of drought, even moderate rain can lead to dangerous runoff, as the parched soil cannot absorb water quickly enough.
“Aridified lands become less capable of handling swelling riverbeds,” forecasters explained. “That’s what we’re seeing across the valley — soil erosion, poor groundwater recharge, and low-level flash flooding.”
Communities including Creede, South Fork, and Pagosa Springs are monitoring river levels closely. The Rio Grande at Del Norte reached a flow of 2,630 cubic feet per second, one of its highest October readings in recent years.
Infrastructure and Road Impacts
The Colorado Department of Transportation’s southwest regional office is monitoring flood-prone structures, including the San Juan Bridge in Pagosa Springs, where engineers plan to inspect the foundation once water levels recede.
While officials remain confident in the bridge’s stability, nearby roadways suffered minor washouts and slope failures from the persistent rain.
What’s Next: A Weak La Niña Winter Ahead
Meteorologists say this flooding episode doesn’t necessarily indicate a stronger La Niña season. According to the National Weather Service, current projections still point to a weak La Niña continuing through mid-December, with temperatures above average and below-normal seasonal moisture expected later in winter.
For now, officials warn residents in southern Colorado to stay alert as rivers remain elevated and additional storms threaten to worsen flooding in the days ahead.
Residents affected by the floods or travel closures can share updates with our newsroom at SaludaStandard-Sentinel.com.
