How Artificial Reservoirs Are Created: Man-Made Lakes on Russia's Volga and Don

Building artificial reservoirs: how people tame rivers

Artificial reservoirs are man-made lakes created by damming or diverting rivers so that water can be stored, controlled, and released when it is needed. If people did not tame rivers, summer droughts would leave communities without water. A river is vast and a person is small, yet human intelligence turns that person into a giant the rivers obey. That giant tells the rivers to save water so that the extremes of "too much" and "too little" become "just enough."

To achieve this, people build dams and create artificial reservoirs. These structures supply cities with drinking water (more: Urban water supply system), and such dams and reservoirs stand on the Volga and the Don. The sections below explain what a reservoir is, how it is engineered, which are the world's largest examples, and what benefits and costs come with reshaping a river into a lake.

What is an artificial reservoir and how is it created

An artificial reservoir, also called a man-made reservoir or man-made lake, is an enclosed body of stored water formed when engineers block or divert the natural flow of a river. Unlike a natural lake shaped by geology over millennia, a reservoir is planned, excavated, and filled on a human timescale. It differs from a pond mainly in scale and purpose: ponds are small and often ornamental or local, while reservoirs hold enormous volumes for irrigation, drinking supply, flood control, and power. The International Commission on Large Dams counts more than 58,000 large dams worldwide, most of them impounding reservoirs of this kind.

Definition and formation of artificial reservoirs

Reservoirs form in several ways depending on the terrain and the water source that feeds them. The most common approach floods a river valley behind a barrier, but engineers also build off-river, bank-side, coastal, cascade, and inter-basin transfer reservoirs. Water arrives through direct river flow, diverted channels, rainwater harvesting, or pumping from groundwater aquifers. The main types include:

• Dammed valleys — a wall closes off a natural valley and the river fills the basin behind it.
• Off-river and bank-side reservoirs — water is pumped from a nearby river into a separate basin during high flow.
• Coastal reservoirs — barrages seal an estuary or bay, as at the Marina Barrage in Singapore or the Saemanguem project in South Korea.
• Cascade and inter-basin transfer systems — chains of reservoirs, or channels that move water between watersheds.
• Service reservoirs and cisterns — covered tanks that hold treated water within a distribution network before it reaches taps.

Filling a new reservoir is a slow process. Before flooding, crews clear vegetation, relocate settlements, and prepare the land; the basin can then take months or years to fill depending on rainfall and river flow. Lake Nasser behind the Aswan Dam took several years to reach capacity, and residents and even monuments such as Abu Simbel had to be moved before the rising water arrived.

Dam construction and water management

Dam construction is the engineering heart of nearly every large reservoir, because the dam holds back the water and regulates how much is released. A dam must resist enormous hydrostatic pressure that increases with depth, so its base is far thicker than its crest. Spillways carry away floodwater safely, sluice gates control discharge into irrigation canals and turbines, and outlet works manage downstream flow. Well-run reservoirs are operated to a rule curve that balances storage for drought against space kept empty for flood control.

Dam construction materials and techniques

Dams are built from different materials chosen to match the site, the geology, and the loads involved. Engineers survey the ground, test the soil, and place markers before committing to a design. The main construction types are:

• Embankment dams — built from compacted earth and rock, the most common and often the most economical form.
• Gravity dams — massive concrete structures that resist water pressure through their own weight, as with the Hoover Dam on the Colorado River.
• Arch dams — curved concrete walls that transfer load into the canyon walls, suited to narrow gorges.

Site selection depends on bedrock strength, valley shape, sediment load, and proximity to the communities the reservoir will serve. Modern reservoir infrastructure increasingly uses instrumentation to monitor seepage, pressure, and structural movement in real time. Similar principles of matching structure to load appear across engineering — the same logic that governs composite materials in engineering also guides how a dam's cross-section is shaped to its stresses.

The world's largest artificial reservoirs

The largest reservoirs cover thousands of square kilometres and rank among the biggest engineered structures on Earth. Lake Volta in Ghana, impounded by the dam on the Volta River, is the largest reservoir by surface area, while the Three Gorges Reservoir in China and Lake Kariba on the Zambezi River between Zambia and Zimbabwe rank among the largest by volume. In North America, Lake Mead behind the Hoover Dam and Lake Powell are the best-known examples.

The Tsimlyansk Reservoir

Using heavy machinery, workers loaded the houses of villages and towns onto trucks and railway flatcars and moved them elsewhere. Now, between the cities of Volgograd and Tsimlyansk, the Tsimlyansk Reservoir shines blue, 350 kilometres long and about 38 kilometres wide. It is a sea made by people. It even holds fish, which anglers introduced here. Where semi-desert and ploughland lay only yesterday, ships now sail — and fishing has become part of daily life along its shores.

The Kuybyshev Reservoir

What happened at Tsimlyansk also happened near Volgograd and Kuybyshev. Here the Volga now forms the greatest artificial reservoir of its kind — the Kuybyshev Reservoir. It is 500 kilometres long and up to 40 kilometres wide, nearly as large as Lake Ilmen.

Reservoir projects around the world

Reservoir building spans every inhabited continent and stretches back thousands of years. In the United States the Tennessee Valley Authority created a chain of reservoirs such as the Cherokee Reservoir, while the U.S. Army Corps of Engineers manages many others including the Gibson Reservoir. The United Kingdom relies on reservoirs such as Lake Vyrnwy Reservoir, the Queen Mother Reservoir, and Honor Oak Reservoir, several operated by Thames Water. Bulgaria's Kardzali Reservoir sits in the Rhodope Mountains, New York City draws on impoundments like the East Branch Reservoir, and Hong Kong's Plover Cove is a coastal reservoir reclaimed from the sea. China's Qingcaosha supplies Shanghai. These global cases show how the same idea is adapted to very different landscapes and climates.

Generating hydroelectric power

Hydroelectric power is one of the most valuable functions of a large reservoir, because falling stored water can spin turbines to produce electricity without burning fuel. The pressure of water held behind a high dam drives generators that feed the grid, making hydropower a renewable backbone for many national energy systems. The link between physics and everyday life is direct here — the same principles that let water turn a turbine underpin much of how science shapes daily life.

The Volga hydroelectric stations

The Volga hydroelectric stations produce as much power as all the hydroelectric stations of Switzerland, Sweden, and Italy combined. They save around 20 million tonnes of coal every year. It is no accident that hydropower is called "white coal."

Hydropower as "white coal"

Hydropower earns the nickname "white coal" because it delivers energy on the scale of fossil fuels while leaving the coal itself in the ground. On the Volga–Don route, hydroelectric stations even power the pumping stations that operate the ship lifts: the Volga supplies the energy that raises its own water up the staircase of locks toward the watershed with the Don.

So the great cycle is completed — a loop that might be called the water cycle within engineering, where human machinery lifts and stores water as nature once did on its own.

Supporting agricultural irrigation

Reservoirs make large-scale irrigation possible by holding water through the wet season and releasing it during dry months when crops need it most. Water diverted from a reservoir travels through canals and pumping systems to fields that would otherwise fail in drought. The FAO estimates that irrigated land, much of it fed by reservoirs, produces a disproportionate share of the world's food relative to its area. Reservoirs also buffer against drought by keeping an emergency supply in reserve for both farms and towns.

The history of irrigation reservoirs reaches back to antiquity. In Sri Lanka, King Parākramabāhu I built the Parakrama Samudra so that, in his words, no drop of rain should reach the sea unused. India's Mission Amrit Sarovar continues that tradition today, restoring and building community reservoirs across the country. Irrigation projects are not always welcomed, however: opposition movements arise where large reservoirs displace people or divert water that downstream users depend on, feeding riparian conflicts over water allocation. Such projects sit alongside modern agriculture as both a lifeline and a point of contention.

Providing cities with drinking water

Reservoirs are a primary source of municipal drinking water, storing raw water that is later treated and distributed to homes. Water drawn from an impoundment passes through screening, sedimentation, filtration, and disinfection before it enters the network. Service reservoirs and cisterns then hold the treated supply close to consumers, evening out daily demand and maintaining pressure. Protecting water quality is essential: managers monitor for contamination, algae, and nutrient loading to prevent health risks, and the water cycle within a treatment system mirrors the natural retention that reservoirs provide.

The advantages of building artificial reservoirs

Artificial reservoirs deliver a wide range of benefits beyond a single purpose, which is why so many are built as multipurpose schemes. Their main advantages include:

• Water storage for agriculture, industry, and municipal use across dry seasons.
• Flood control — empty storage capacity absorbs storm surges and protects downstream communities.
• Hydroelectric power generation without fuel combustion.
• Navigation, as deep water and locks let ships pass reaches that were once too shallow.
• Recreation and eco-tourism, from boating and angling to lakeside tourism.
• Groundwater recharge, as stored water seeps down to replenish aquifers.

Artificial lakes in arid and desert regions

Artificial lakes are especially transformative in arid and desert regions, where they turn scarcity into reliable supply. In the United Arab Emirates, the Al Qudra lakes were engineered in the desert near Dubai to create habitat and recreation where none existed. Ancient desert civilisations understood the same principle: the Marib Dam in Yemen and the Jawa Dam in Jordan are among the oldest known water-control structures, and the Aswan Dam turned the Nile's floods into the year-round store of Lake Nasser. In such climates, reducing evaporation is critical, and engineers deploy shade covers, floating barriers, and reflective materials to keep precious water from vanishing into the air.

Effects on biodiversity and ecosystems

Reservoirs reshape ecosystems by converting flowing river habitat into standing water, a shift limnologists describe as moving from a lotic to a lentic environment. This change supports new wetland biodiversity and fisheries but disrupts species adapted to running water. Dams block fish migration and spawning routes, alter benthic communities on the riverbed, and trap sediment that once nourished downstream deltas. The Journal of Great Lakes Research and the Water Alternatives Journal have documented how these geomorphological changes cascade through food webs. Reservoir creation also triggers a "trophic upsurge" — a burst of productivity as flooded vegetation releases nutrients — followed by a "trophic depression" as that pulse fades, sometimes accompanied by cultural eutrophication where nutrient overload degrades water quality.

Ecological consequences: methane emissions and carbon sequestration

Reservoirs have a mixed climate footprint, acting as both carbon sinks and greenhouse-gas sources. Organic matter decomposing underwater in oxygen-poor conditions releases methane, a potent greenhouse gas, so a reservoir is not automatically "clean" energy. At the same time, sediment settling on the bed can lock away carbon over long periods, providing a measure of carbon sequestration. Thermal stratification — warm water layered over cold — and the discharge of unnaturally cold or warm water downstream add thermal pollution to the list of ecological concerns that an environmental impact assessment must weigh.

Preventing bank erosion and geomembrane liners

Bank erosion and seepage are managed with engineered liners that seal a reservoir's floor and slopes. Geomembrane liners — flexible synthetic sheets supplied by specialists such as Western Environmental Liner — prevent water loss into permeable ground and stabilise banks against wave action. A geomembrane is especially valuable in porous desert soils, where an unlined basin could lose much of its water before it is ever used. Combined with vegetation and rock armouring, these barriers extend a reservoir's life and protect surrounding land.

How climate change affects water availability

Climate change is intensifying the very extremes reservoirs are built to manage, making their role both more valuable and more precarious. Shifting rainfall, longer droughts, and fiercer floods strain water infrastructure, while higher temperatures increase evaporation from open reservoir surfaces. Agencies including UNEP warn that water scarcity now threatens billions of people, and reservoirs are central to the response. Cities are adopting the Sponge City Strategy — pioneered in China — to absorb and store stormwater, and rainwater harvesting captures supply at the source. Managing reservoirs wisely under a changing climate means planning for a future in which both too much and too little water arrive less predictably.

The history of reservoir development

Reservoirs are among humanity's oldest engineering achievements, with examples spanning more than four millennia. The Jawa Dam in Jordan dates to roughly 3000 BCE, and the Marib Dam in Yemen sustained a desert kingdom for centuries. In Sri Lanka the vast Parakrama Samudra reservoir shows how ancient societies mastered water storage at scale. From those beginnings, reservoir engineering advanced through Roman cisterns, medieval millponds, and finally the great concrete dams of the twentieth century, when organisations like the Tennessee Valley Authority industrialised the practice across whole river basins. Water expertise has long been shared and codified — knowledge that today reaches the public through platforms ranging from technical societies to educational resources online.

Construction timelines: from the Suez to the Volga–Don canal

Building the great water routes has always demanded enormous effort over long stretches of time, though modern technology has compressed those timelines dramatically.

• The construction of the Suez Canal lasted ten years.
• Hundreds of thousands of labourers spent a total of 21 years on the construction of the Panama Canal.
• The Kiel Canal took 35 years to build.
• Thanks to the achievements of modern engineering and human ingenuity, the Volga–Don canal was built in just three years.

The cost of building and maintaining reservoirs

Reservoirs carry high costs across their entire lifespan, not only during construction. Capital expenses cover the dam itself, land acquisition, resettlement of displaced communities, and the environmental impact assessment required before work begins. Ongoing costs include sediment management, because sedimentation gradually fills the basin and reduces storage; dam safety inspection; water-quality monitoring; and eventual decommissioning. The main cost drivers are:

• Construction — materials, excavation, and the dam structure, which for large concrete dams can run into billions.
• Social costs — compensation and relocation for communities lost to flooding.
• Environmental mitigation — fish passages, liners, and habitat restoration.
• Maintenance — dredging sediment, repairing structures, and monitoring water quality over decades.

Weighing these costs against the benefits of water security, power, and flood protection is the central task of anyone planning a reservoir, and it is why long-term sustainability now guides project design as much as raw engineering capacity.

Conclusion

Artificial reservoirs remain one of the most powerful tools humanity has for reconciling the mismatch between where and when water is available and where and when it is needed. They water crops, quench cities, generate clean power, tame floods, and open rivers to navigation — yet they also displace communities, alter ecosystems, trap sediment, and emit greenhouse gases. From the ancient Jawa Dam to the Volga's engineered seas and today's sponge cities, the story of reservoirs is the story of people learning to command rivers while learning, too, the responsibilities that command carries. Built and managed with care, reservoirs turn "too much" and "too little" into "just enough" for generations to come.