On Monday night there was some rain, ice pellets, and snow. Tuesday morning I measured 0.4 inches of snow depth. The rain/snow gauge revealed a moisture content for this precipitation to be 0.15 inches (I report to CoCoRHaS – Community Collaborative Rain, Hail, and Snow Network).
After 24 hours I checked my depth of soil moisture very near the same place as previously. The depth of moist soil (measured with the Brown Probe) was 6.25 inches. Although there had been some evaporation loss of moisture, I still gained 0.75 inches of additional depth of soil moisture. This is still not enough to provide the needed 2 to 3 feet of moist soil that trees and shrubs need, so irrigation is still necessary. Perhaps there will be more precipitation this week – there is a forecast 20% chance of precipitation for a couple of days later this week (National Weather Service). It is unlikely that there will be enough to make irrigation unnecessary, but all precipitation is valued here in the Southwestern U.S.
I decided to check the depth of soil moisture in another area where water drains from the roof (no rain gutters at this location, yet). At one place the depth of moist soil was 29 inches and a few feet away where the water collects the depth of moist soil was 36 inches. The Brown Soil Moisture Probe was also used for these measurements. Trees and shrubs in this area would have adequate moisture and not need irrigation. This illustrates the benefit of utilizing “harvested” rain water whether by planting where the runoff water collects or by collecting and redirecting the precipitation.