For hydrologists, the new year comes three months early, when October 1 marks the start of the new water year. But why? Why not just have the water year start on January 1st? This is due to patterns of water availability, water demand, and water use common in much of the northern hemisphere. October marks a transition time, when the growing season is ending, and snow is starting to accumulate in the mountains. The mountain snowpack builds up through the fall, winter, and spring. When the snowpack melts, it supplies water used during the summer. Hydrologists track water year total precipitation, peak snow accumulation, and streamflow starting each October 1 through to September 30 of the following year.
For Stream Tracker in the Colorado region, the new water year signals snow and rain. Most streams that are intermittent will have most likely dried up by this time of year through the heat of the summer months. However, both rain and snowmelt can bring flow back to dry channels. Are you curious to see which channels respond to fall and winter rainfall and snow melt? So are we! While these storm events are less predictable, great times to stream track are directly following a large rainfall event or when warm temperatures follow snowfall. We expect most of the visible stream changes to be in the lower elevation foothills and plains. At high elevations, most small streams will be covered with snow throughout the winter. In these areas, the snow that sticks around and accumulates through the winter can contribute to streamflow during spring runoff. Stay warm through the coming months, keep stream tracking, and start getting excited for when the streams once again come alive.