Inflow Forecasting for Muskrat Falls Flood Management

Automatic data acquisition and inflow forecasting

Scheduled dam construction at reduced cost

Improved worker safety at dam site

Challenge

During the construction of the Lower Churchill hydroelectric project in Labrador, Canada, Nalcor Energy needed to properly manage scheduling at the site.
The Churchill Falls Generating Station has plant outflows ranging from 1000 m³/s overnight to 3000 m³/s during the day, so accurate inflow forecasts were also needed.
The outflows significantly impact water volume at the Muskrat Falls dam site and the lower river, where peak spring flows can be as high as 6500 m³/s.
A software tool that could both manage the construction schedule and provide accurate forecasts of inflow volumes, especially during the spring runoff, was needed.

The inflow Vista module of Vista DSS™ was set up and calibrated for the lower Churchill River.
The setup included six subwatersheds.
Flow releases from the upstream Churchill Falls hydroelectric generation station on the Churchill River, which constitute a large portion of the river flow at Muskrat Falls, are represented in the model.

Vista produces continuous inflow forecasts that are updated daily, and route flows down the Churchill River to the Muskrat Falls project.
Vista also projects outflows and water levels at the Muskrat Falls dam site.
For short-term inflow forecasts, Vista features automatic access of real-time hydrometric and weather data, snow course data, and pertinent meteorological forecast data.
To assess the risk of the river flow flooding the construction site, extended streamflow prediction forecasts are generated periodically using observed and historical temperature and precipitation data.