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M anaging hydropower reservoir operations is a tricky science. It involves the ability to accurately predict how much water should be saved in reservoirs so that the utility can continuously produce energy, especially when electricity prices are high. Many utilities struggle with this challenge because it is difficult to produce accurate inflow forecasts. To make this decision, utility Hydro-Quebec analyzes daily rainfall or snow melt forecasts to determine the amount of potential inflow to its reservoirs. The utility — which generates, transmits and distributes electricity for the entire province – faces the challenge head on with the help of geographic information system (GIS) technology. With 62 hydroelectric generating plants and 27 large reservoirs, Hydro-Quebec is the largest electric utility in Canada and one of the world's largest hydroelectric producers. The government- owned utility has been successful in generating large quantities of renewable electricity at competitive prices due in part to its technological innovation. This innovation is evident in how the utility manages its reservoir operations. It takes a 10-person team to validate the data that will be entered into mathematical models to support decision-making. Every day, Hydro-Quebec's in- house meteorologist compares weather forecasts from Environment Canada, as well as forecasts from the U.S. and European models, to determine differences and modify the Environment Canada forecast model to be used for analysis. At the same time, other staff members validate other data, including reservoir levels, water flows and power flows. After the forecast of how much water will fall into the reservoirs is made, operators then schedule how much energy will be produced for the next day. Recognizing the value of a geographic approach In 2006, Hydro-Quebec developed homegrown GIS software to assist operators with their decision-making. However, the system lacked a real geographic component and had limited visualization and analysis capabilities. It integrated bitmap images of rain coming into the reservoirs, but the images were not associated with their location. As well, it was difficult to understand the representation because multiple layers of lines were overlaid on top of one another. To help improve the accuracy of its forecasts, Hydro- Quebec leveraged ArcGIS technology from Esri, which provides a comprehensive GIS platform for the energy and water resources industry. The utility has used the technology for many years and has found ArcGIS to be the most cost-effective solution for advanced desktop and custom application development. Hydro-Quebec used Esri's ArcPy tools to script GIS functionality in the Python programming language to build a program that retrieves weather forecasts by Environment Canada from the utility's file transfer protocol (FTP) site. It then processes By Francois Gilbert Francois Gilbert is a senior water resources engineer for Hydro-Quebec. W a t e r s h e d M a n a g e m e n t Streamlining Operations with Software By creating a new suite of analytical software, Canadian utility Hydro-Quebec was able to build a system better suited to managing its dozens of reservoirs while more accurately balancing water resources and power generation. Hydro-Quebec's previous system could only display one layer of data at a time. In this image, a 24-hour rain forecast is shown using isolines. Figure 1 — The Old System ®

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