Hydrology
Over a century of streamflow monitoring from the seven main
sub-catchments draining the Central Wasatch indicate that mean annual
water yield ranges from 18% to 63% with higher water yield from
colder, wetter, steeper catchments (Gelderloos, 2018; Jamison, 2020;
Wolf, 2020). Hydrochemical observations from U.S. Geology Survey (USGS)
baseline network indicate that most of this surface water discharge has
had extensive interaction with the subsurface (Godsey et al., 2009). The
evidence that snowmelt drives both surface water discharge and
groundwater recharge has led to extensive focus on surface
water-groundwater interactions using a suite of tracers (Manning &
Solomon, 2004; Manning et al., 2005). These studies demonstrate that
mountain block recharge is large, driven by snowmelt, and that regional
groundwaters are dominated by modern water with apparent3H/3He ages of 5 to 50 years.
Younger waters are found close to the mountain front. Recent findings
that snowmelt is decreasing due to long-term warming (Jamison, 2020)
while proceeding more rapidly due to episodic dust deposition (Skiles et
al., 2018) suggest that historical patterns in recharge and streamflow
are unlikely to predict future water supply. These results have
important implications for drinking water supply given that winter
montane precipitation is an important source for tap water in the Salt
Lake Valley (Jameel et al., 2016; 2018).