RRP Flow Preview 2021

This is a reboot of my When Does the Season Start post, with some current updates. I’ll focus on River Run Park, since it probably sees the most surfers of any surf wave in the state. Very generally, surfable flows tend to begin in late April or early May, but there are plenty of outliers.

As of late March, 2021, our Front Range snowpack is looking about average, with the western mountains a little below average:

Now we’ll take a look at past years to look at how snowpack and flows have lined up. In my earlier post I also looked at reservoir levels, but it’s so tough to discern how each reservoir impacts the analysis that I’ve simplified things to just look at total snowpack. That said, it’s worth considering that Colorado is generally coming out of a drought, and dry soil tends to absorb a lot more water than wet soil, leaving less flow for the rivers.

2020 Snowpack vs. Flows

Graph of  Discharge, cubic feet per second

2020 felt like a stolen season at RRP. Flows were low, particularly when compared to a slightly above-average snowpack. I thought the likely culprit was the expansion of Chatfield Reservoir’s capacity. But the bad news is that most of the water was eaten up by a hot, dry spring. Current reports are that hardly any progress was made in filling the new capacity at Chatfield. Which is not great news for the coming 2021 season, in the event the Corps of Engineers uses water to fill up the new capacity. But, as this piece goes into in some more detail, the network that runs water through RRP is complicated and has a lot of moving parts.

2019 Snowpack vs. Flows

Graph of  Discharge, cubic feet per second

This was a strong snowpack and a strong surf year, with surfable flows running from the beginning of June through July.

2018 Snowpack vs. Flows

Graph of  Discharge, cubic feet per second

The counterpoint to 2019 – a low snowpack and low flows, with only a few surfable days.

2017 Snowpack vs. Flows

A pretty solid snowpack and pretty solid flows. May 12, 2017  was basically the beginning of the season in earnest.

2016 Snowpack vs. Flows

An unusually good flow year in light of the snowpack.

2015 River Run Park Flows

More like 2017 than 2016, with flows staying pretty low aside from the occasional rain/snow spike until the very end of April/beginning of May, but then they went nuts. Seems out of character for the snow pack.

2014 Snowpack vs. Flows

Another variation, it looks like 2014 saw a spike in flows for the second half of April, followed by things falling off and getting spotty in May, with steadier flows in the second half of May and into June. Overall, a pretty decent year.

2013 Snowpack vs. Flows

An uneven low water year, without much in the way of flows over 200 cfs. This was a drought year. Can’t end on that note, so let’s pull 2012:

2012 Snowpack vs. Flows

Ug. I don’t want to talk about this one. One more:

2011 River Run Park Flows

Unusual, compared to the others; the flows turned on but they didn’t do so until the second half of June.