There are two questions the average Colorado River manager gets asked a lot: — how’s the snowpack and how’s the runoff? Know Your Water News is starting a suite of graphics to help explain the snowpack and runoff seasons compared to the historic 30-year averages. Since we’re currently in prime runoff season, this is the first graphic – Runoff in the Upper Colorado River Basin.
What you’re seeing here is the runoff, which means the amount of water flowing into the reservoirs as this year’s snowpack is melting. We’ve been in runoff season since April and this shows the runoff as of the end of June.
Note that the 2020 runoff thus far is trending under the 30-year average. This is due to dry soil conditions in fall 2019, followed by a dry, warm 2020 spring that depleted the snowpack. Thus, it is likely the Colorado River Basin will continue in Tier Zero shortage status in 2021, but the dry year increases the vulnerability of a Tier One shortage status as early as 2022.
Designer’s Note by Travis Dins – While designing the Colorado River Upper Basin runoff infographic, I knew I would be converting complex data into something easily digestible. At a glance we wanted people to understand a portion of the water cycle – the “runoff,” melting snowpack from the Colorado Rockies, which flows into the large reservoirs where CAP gets it water. I wanted to keep it fun and simple — a less-is-more approach. The graphic went through several iterations before ending up here. We wanted to ensure the graphic was visually engaging but also accurate. We realized we needed a point-of-reference, which was to compare the 30-year average to the current year. I chose dark blue for the 30-year average and a transparent lighter blue for the current year so they could be quickly and easily differentiated.