Forecasting seasonal run-off is an important activity in hydroelectric power management. In many parts of the world, water released from the snow pack in spring is often the primary source of water for dams. Therefore, the amount of water contained in a snowpack, or its Snow Water Equivalent (SWE), is an essential parameter to measure through the winter and spring.
Effective SWE measurement is key
To make sound water management decisions, it is essential that SWE measurements be as effective and accurate as possible. Water in a snow pack is determined by depth, density, type of snow, changes in the pack, previous freeze/thaw cycles, recent rainfall events, etc.
Of course, the actual amount of water affecting a river basin would depend on weather conditions during the melt and potential absorption into the soil, but knowing how much water is available in the snow pack is valuable for those managing reservoirs and flood forecasting.
There are various methods to measure SWE, including manual snow cores, snow pillows, snow scales, precipitation gauges, and non-contact SWE sensors such as the CS725. We recommend a non-contact, automated method because it is friendly to the environment, cost effective, and not susceptible to errors caused by snow bridging.
SWE monitoring for hydroelectric power forecasting in Canada
This case study demonstrates how forecasters in Northern Canada use year-round snow water equivalent (SWE) and other meteorological monitoring to forecast hydroelectric power output.