The care and feeding of snow pillows

Soil Conservation Service appointed an Evaluation Team in 1977 to evaluate the adequacy of the snow pillows and identification of causes for failure when failures occurred. This paper is a result of some of these findings. Several different designs and types of snow pillows have been built and tested. Two major types have evolved, the butyl rubber pillow and the stainless metal pillow. The snow pillow has been accepted by SCS and the California Department of Water Resources as their standard snow water equivalent sensor. Several years of record have demonstrated the fact that the snow pillow can accurately measure the snow water equivalent. There is also documentation that there can be problems in using this device. Although pillows appear to be rather simple devices, they are quite complex. Trained personnel must be available to install and maintain these devices to obtain good quality data. Certain procedures must be followed in order to obtain a satisfactory operational record.