2018 Streamflow and Precipitation Update
Updated: Apr 25, 2020
How low can the flow go? As the 416 and Burro wildfires rage near Durango, it's obvious that the streamflow in the San Juan River is more than just water under the bridge. It's a reflection of the moisture available in our watershed. Normally this time of year, lingering winter snowpack creates prime rafting conditions, but this year, tubing season is even in jeopardy (and so are the fish and possibly your petunias). Currently, 121 cfs is meandering though downtown Pagosa Springs, which is only 10% of the historic median, but the flow is not as low as 2002. At this time in 2002, there was only 54 cfs under the bridge!
Normally, the high country snowpack sustains the streamflow through mid-July keeping the river above 200 cfs until early August. Unfortunately, this year, the river dropped below 200 cfs on June 8th. However, in 2002, peak flows barely eclipsed 200 cfs, and then slowly receded to a record low of 7.5 cfs on 8/16/02! At that trickle, you easily jump across the San Juan River (or hop across the river on large rocks). Not only was the snowpack in 2002 a bust, so was the monsoon season. Runoff generating rains didn't arrive until September.
Normally, the Upper San Juan receives about 53 inches of precipitation annually (rain and snow combined) from October 1st through September 30th. We normally have 41.2 inches of precipitation by now, but we've only received 21.7 inches. However, we're still doing better than the 16.9-inch total that we had at this time of year in 2002. June is usually our driest month, but usually we have enough snow to sustain us until monsoon season, which generally arrives in mid-July and sustains us into the fall.
There is good news though: an early Pacific hurricane with an unusual track (they usually track further west, away from the west coast) is breaking up near Baja Mexico and spinning moisture toward our region. For the sake of the lives and homes threatened by wildfire, hopefully we'll get a drenching rain this weekend, followed by an early start to monsoon season!