For our province’s electricity system, water is fuel. Hydropower accounts for more than 80% of Newfoundland and Labrador’s total electricity production, increasing to 98% with the completion of Muskrat Falls and the Labrador-Island Link. A series of watersheds, reservoirs, dams and generating facilities are responsible for producing all that energy, which powers our communities and everyday lives.

You might know how hydroelectric plants work in general – storing and using water to turn turbines and convert the energy into electricity. But the amount of this renewable energy source at our disposal is really controlled by Mother Nature and the natural water cycle. So, how is the supply of water itself actually managed to optimize power production?

We dive into a day in the life of our Water Management team with Evan Porter.

What led you to the world of water management?
EP: The sustainability aspect is what first attracted me to working in water resources, from both an employment and environmental perspective. I worked for an oil company for most of my engineering work terms and that experience motivated me to take my career on a different path. After graduating university, I was lucky enough to land a job as a hydrotechnical engineer with a well-established consulting firm. A few years later, I took a role with the Lower Churchill Project, where I was responsible for managing the Muskrat Falls reservoir in its early stages. From there, I joined Hydro’s water management team in 2018, which was a great fit!

What exactly does a hydrotechnical engineer at Hydro do?
EP: It’s our job to ensure there is always enough water in our reservoirs to generate electricity for customers. It sounds simple, but it involves so many variables. We constantly analyze water levels, and the amount of water flowing into and out of reservoirs, which changes day to day and throughout the year. We also determine how much water we need to move from each reservoir to keep our generating plants operating as they should. This sometimes means we may need to release, or spill, water in some areas, or that there is excess electricity we can export to other markets.

During the winter when demand for electricity is highest, our team also determines how much generation from other sources needs to be dispatched to control how much water is being used and to ensure we maintain enough to supply customers with electricity until spring, when the snow that has accumulated in the watersheds melts and refills the reservoirs.

We’re also responsible for directing operation of spillway gates when there’s too much water for the reservoirs to store. Our team forecasts when and where controlled spills need to happen and provide directions to operators and field staff to open and close gates to keep water levels within allowable limits.

What goes into managing our reservoirs and why is it so important?
EP: It requires analyzing a lot of information: reservoir water levels, inflow and outflow amounts, forecasted weather conditions, customer electricity demand, capability at our generating facilities, and so much more. We use specialized software that takes in all of this information across our entire electricity system, and then identifies how much water should be moved from each reservoir, how much electricity each hydro generating facility should produce, and how much electricity is needed from other sources like Holyrood or Muskrat Falls. All this helps ensure we’re generating as much electricity as possible from the water that flows into our reservoirs. And, it feeds into an operating strategy that Hydro’s electricity system operators then use to make decisions on where to increase or decrease generation based on customer electricity use.

So, weather conditions and events like heavy storms can impact the reservoir system?
EP: Absolutely. We keep a constant eye on provincial and regional weather forecasts, especially when there’s a significant rainfall event or a hurricane on the way. We’ll assess how much precipitation is expected and what watersheds and facilities will likely be impacted. In the Spring, we’re also watching for mild temperatures that could really accelerate snowmelt and fill reservoirs rapidly. And, of course, we closely monitor how quickly reservoir conditions are changing so that quick decisions can be made to release water when and where necessary. It can be quite a demanding process during extreme weather or when we need to release water at multiple locations!

How do reservoir levels affect electricity production?
EP: The water in our reservoirs is what spins our plant turbines and makes most of the electricity that’s used each day in Newfoundland and Labrador. So, it’s vital to manage the supply properly.

Every reservoir has a low supply level and a full supply level, or “maximum operating level.” When reservoirs have a lot of water, normally that means we’re able to rely more on our province’s clean, renewable energy source. The amount of water in a reservoir, and the amount of water flowing through a plant, also impacts how efficiently the plant can produce electricity. It’s a delicate balance, and one that we’re continuously monitoring to ensure we’re managing water levels to best meet customers’ needs safely, reliably and as cost-effectively as possible.

Is there something you wish people knew about your job?
EP: It’s rarely routine. There are always unique challenges – circumstances and conditions that are not quite like any situation we’ve handled before. It keeps us on our toes! We have a great team of dedicated people that always make sure our water is managed responsibly and safely.