Hydropower is used by more than 150 countries to generate electricity, making it the world’s largest source of renewable power at 14.3% of global electricity supply. But electricity generation is only part of the story. The same dams and reservoirs that spin turbines also control floods, irrigate farmland, store energy for the grid, and supply drinking water to cities. The users range from entire national grids down to individual homeowners running a turbine on a backyard stream.
Countries That Rely on Hydropower
China, Brazil, Canada, the United States, and India are the world’s largest hydropower producers, collectively operating the majority of global capacity. The Global Energy Monitor tracks 5,617 hydropower projects worldwide with a combined operating capacity of 1,216 gigawatts, enough to power hundreds of millions of homes simultaneously.
Some countries depend on hydropower for nearly all their electricity. Norway generates over 90% of its power from hydro. Paraguay, Ethiopia, and Nepal also draw the bulk of their electricity from river systems. In these places, hydropower isn’t a supplement to the grid; it is the grid. Regions within larger countries can show similar patterns. The Pacific Northwest of the United States and the province of Quebec in Canada both get the majority of their electricity from hydroelectric dams, giving residents some of the cheapest power rates in North America.
Electricity Generation at Scale
The primary use of hydropower is straightforward: water flows through turbines, spinning generators that feed electricity into the grid. This power reaches residential customers, commercial buildings, factories, and public infrastructure. Unlike solar or wind, hydropower can run continuously as long as water is flowing, which makes it a reliable baseload power source. Operators can also ramp generation up or down in minutes by controlling how much water passes through the turbines, giving grid managers a tool for matching supply to demand throughout the day.
Industrial users are among the biggest consumers of hydroelectric power. Aluminum smelting, steel production, and chemical manufacturing are enormously energy-intensive, and companies in these sectors have historically built operations near large hydroelectric facilities to access cheap, steady electricity. Iceland’s aluminum industry, for example, exists largely because of its abundant hydropower.
Grid-Scale Energy Storage
One of hydropower’s most valuable modern roles has nothing to do with generating new electricity. Pumped storage hydropower acts as a giant rechargeable battery for the electrical grid. The setup uses two reservoirs at different elevations. When electricity demand is low (or when wind and solar are producing more than the grid needs), cheap power pumps water up to the higher reservoir. When demand spikes, that water is released back down through turbines to generate electricity on demand.
This technology is the most dominant form of energy storage on the electric grid today. In the United States, pumped storage accounts for 88% of all utility-scale energy storage, according to a 2024 federal report. As solar and wind capacity grows, pumped storage becomes even more critical. It solves the intermittency problem: storing surplus renewable energy during sunny or windy hours and releasing it during evenings or calm days. Utilities, grid operators, and energy planners are the primary users of this capability.
Flood Control and Water Management
Many hydroelectric dams serve double duty as flood protection infrastructure. By capturing floodwaters behind the dam and releasing them gradually under controlled conditions, operators can prevent catastrophic downstream flooding that would otherwise damage towns, farmland, and roads. The Tennessee Valley Authority’s system of dams in the southeastern United States, for instance, was built as much for flood control as for power generation.
Dams also give water managers precise control over river flows. This means they can time water releases to maintain healthy conditions for fish and other aquatic species, improve water quality through targeted flows, and ensure that downstream communities have a reliable water supply during dry seasons. Municipal water systems in many regions draw directly from hydroelectric reservoirs, making the same infrastructure serve both energy and drinking water needs.
Irrigation and Food Production
Farmers are significant users of hydropower infrastructure, even if they never think about the turbines. At least 276 dams in the United States alone provide both hydropower and irrigation services. The reservoirs behind these dams store water during wet periods and release it to agricultural land during growing seasons, supporting food production in areas that would otherwise be too dry to farm reliably. Large-scale irrigation systems in the western United States, parts of India, Egypt, and Central Asia all depend on dam infrastructure that often generates electricity as a co-benefit.
Small-Scale and Off-Grid Users
Not all hydropower involves massive dams. Microhydropower systems, typically generating under 100 kilowatts, serve homeowners, small businesses, farmers, and ranchers. A system producing just 10 kilowatts can supply enough electricity for a large home, a small resort, or a hobby farm. These systems work by diverting a portion of a stream or creek through a small turbine, and they can run around the clock with minimal maintenance.
In developing countries, micro and small hydropower plays a particularly important role in rural electrification. Remote villages that are too far from the national grid to justify transmission lines can build small community-scale hydro systems on nearby rivers. These provide power for lighting, phone charging, grain milling, and other basic needs that transform daily life. Nepal, Peru, and parts of sub-Saharan Africa have thousands of such installations, often funded by development organizations and maintained by local communities.
Recreation and Navigation
Hydropower reservoirs create large bodies of water that support recreation industries worth billions of dollars. Boating, fishing, swimming, and lakeside tourism all depend on reservoirs that exist because of dam infrastructure. In the United States, Army Corps of Engineers reservoirs alone attract hundreds of millions of visitor-days per year, supporting local economies built around outdoor recreation.
Dams also support inland navigation by maintaining water levels deep enough for commercial shipping. The lock-and-dam systems on the Mississippi, Ohio, and Columbia rivers allow barges to transport grain, coal, and manufactured goods across the country. Shipping companies and agricultural exporters benefit directly from water levels controlled by dam infrastructure that often generates hydroelectric power at the same time.