The March 2019 @CWCB_DNR “Floodstage” newsletter is hot off the presses

Cherry Creek Flood August 3, 1933 — photo via the Denver Public Library

Click here to read the newsletter. Here’s an excerpt:

As of mid-February, Colorado’s statewide snowpack sat at 108% of normal. Snowpack is higher in the northern and eastern basins and lower in the southwestern basins. The climate forecasts through the runoff season suggest that these numbers could climb higher as fore- casts indicate a wet spring statewide.

Higher snowpack percentages can increase the possibility of snow- melt flooding. Generally, watersheds are monitored for this once they reach 130% snowpack. Currently, no watersheds exceed this threshold, but state officials continue to monitor conditions due to the wet climate forecast moving forward. To view snowpack conditions and better understand the potential flood threat in your location, visit the Natural Resources Conservation Service’s Snow Telemetry (SNOTEL) and Snow Course Data and Products page.

It is worth mentioning that, as indicated by looking back through Colorado’s history, the majority of flooding events occurring through- out the state are rain-based and not snowmelt-based. In fact, the last year of widespread snowmelt flooding was in 1984, although isolated instances have occurred since then. One area of ongoing concern relates to rain-on-snow events, in which high elevation, late spring rainstorms fall on still surviving snowfields. This can quickly exacerbate runoff and create problems that wouldn’t exist in the absence of either the rain or the snow.

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