The South Platte basin, with Boulder County as part of this watershed, is at 66% SWE. (Photo: Shutterstock).
Adrian Card, Colorado State University Extension
Boulder County and the areas surrounding it, including the high mountains, are in severe to extreme drought (D2 and D3 in drought jargon, according to the Drought Monitor). While this region of Colorado enjoyed a “donut hole” status through much of the state’s 2021 drought, we have now joined the remainder of Colorado, which is in some form of moderate (D1) to extreme (D3) drought.
If you are new to Colorado, you will soon learn that snow is the source of most the hydrology in the state. While there is a minor exception in the Republican river basin, no river flows into Colorado, earning it the title “mother of rivers”, rivers fed by snowmelt. Therefore everyone – commercial and residential users, farmers and ranchers, rafters and fishermen – keep an eye to the snowpack as we enter a water year, Oct. 1 through Sept. 30.
Currently, that water year is looking dismal. Warm and dry weather have excluded snowfall gains through most of the water year into mid-December. Recent snowfall has added to the overall picture, with a statewide average snow water equivalent (SWE) reported at 54% according to the Natural Resources Conservation Service. Imagine if you melted all the snow from a pipe inserted into in the snowpack and converted that to inches of water. Like measuring rain in a rain gauge, that is SWE. The South Platte basin, with Boulder County as part of this watershed, is at 66% SWE. Of critical importance to Coloradans, the Southwest part of the state, the San Miguel basin and Upper Rio Grand basin, are showing 31% and 33%
Mother nature always bats last, so water managers in the state know most of the big snow events come after the new year. By late April we have typically reached maximum snow deposition and have a relatively clear picture of SWE contributions to hydrology. Periodic rainfall events can charge the hydrology with more water but since these cannot be predicted are just a bonus when they happen.
The National Oceanographic and Atmospheric Administration publishes short- and near-term temperature and precipitation forecasts through its Climate Prediction Center (CPC). The last CPC 30-day forecasts issued November 30 showed Colorado at a 40 to 60% probability of above normal temperatures. No surprise here given our weather lately. Interestingly, the state is divided nearly evenly by a horizontal line, approximately in the I-70 corridor, with a less likely warm forecast above and more likely forecast below this line. All but the Southeast corner of the state has equal chances of normal precipitation for the period.
The three month CPC forecasts issued November 18 show all but a tiny Northeastern sliver of the state having a 40 to 50% probability of above normal temperatures and all but the southern third of the state having equal chances of a normal precipitation outlook with the southern third in a 33-40% probability of below normal precipitation.
Overlay the current meager snowpack for Southwest Colorado and lower probability of precipitation through February and the prolonged drought there is still on the table now. Given the decent snowpack to date in the South Platte basin and favorable precipitation forecasted through February, the Boulder County area could emerge from drought by spring.
While it is premature now to plan for 2022 water year drought contingencies, this is a strong reminder that climate is in flux, warmer and drier maybe the trend for the Boulder County area going forward, additional watering of critical municipal landscapes may be the norm, even during winter dormancy to prevent injury and death to perennial plants.
Water storage projects are highly controversial but could be the buffer needed to bridge dry water period.
Farming and ranching, normally risky businesses, now look even riskier.
Mother nature will determine the water Colorado gets. It is our job manage it wisely.
By Adrian Card. Adrian is the agriculture extension agent for Colorado State University Extension in Boulder County. For more information on agriculture, visit extension.colostate.edu/agriculture
