CIEDM Campaigns for Awareness of Low Water Level Impacts on Power Generation - The Case of Colorado River

Introduction

This article is written and shared as part of California Institute of Environmental Design & Management (CIEDM) participation in the global and national celebrations of World Water Week (WWWeek) and National Hydropower Day (NHD) 2026, observed respectively on August 23-27 and August 24, to raise public awareness of these two awareness campaigns at a critical time of low water level crisis currently taken places in many waterways and water bodies around the globe. The case study is on the Colorado River, the most significant river in the arid region of American Southwest.
Due to current watershed conditions in many water bodies and waterways around the world, including below-expected precipitation, and prolonged severe drought and extreme heat, a number of rivers, lakes and reservoirs are encountering various issues with low water levels. For example, low summertime water levels are a routine problem for navigation on the River Rhine, especially in recent years, but the intense drought conditions affecting Western Europe have left the waterway all but unnavigable at certain points since July 2026 and thus sending freight rates to record highs. Similarly, Panama Canal begins reducing daily transits due to declining water levels.
Low water levels impact not only on shipping but also energy sector. With extreme heat striking Europe this summer and causing increased demand for power to cool various types of operations, power plants on the other hand, including nuclear power ones, along the Danube River are completely or partially shutting down in Romania, Hungary and Bulgaria, due to the River’s low water levels.

The Story of Colorado River

The Colorado River is a vital 1,450-mile waterway in the United States West starting in the Rocky Mountains of Colorado and flowing to the Gulf of California in Mexico. The main water source for the River is winter snowpack in the Rocky Mountains of Colorado, where the river originates in Rocky Mountain National Park. Ranked as the 5th-longest river in the US, the transboundary river crosses five states: Colorado, Utah, Arizona, Nevada, and California, plus Wyoming and New Mexico in its wider basin. It supplies water and power to 40 million people and millions of acres of farmland across the seven states and Mexico.

However, in recent years, the River system has been experiencing a severe water shortage. Major reservoirs like Lake Mead and Lake Powell are at critically low levels -- hovering around 27% capacity, as of August 2026. The main causes of the shortage are:
• Historic Drought: A multi-decade mega-drought in the American West has drastically reduced natural water flows.
• Shrinking Snowpack: Less winter snow in the Rocky Mountains means less spring runoff feeding the river.
• High Evaporation: Hotter weather causes more water to evaporate from the system's major reservoirs.
• Over-Allocation: The 1922 compact for river water allocation to the stakeholders for 40 million people has divided more water than the river actually produces.

Anchor Stem Dams for Hydropower Generation

Regulated by 15 main-stem dams and hundreds on tributaries the River system’s two largest structural and economic anchors are the Hoover Dam and the Glen Canyon Dam
• Hoover Dam - Located on the Nevada-Arizona border, it stands 726 feet tall, creates Lake Mead, and provides vital flood control, municipal water, and hydroelectric power for the Lower Basin states.
• Glen Canyon Dam.- Located in Page, Arizona, this 710-foot-tall concrete arch-gravity dam forms Lake Powell and regulates Upper Basin water deliveries.

The Colorado River generates hydroelectric power through these two main-stem dams, producing thousands of gigawatt-hours of clean energy annually. This electricity is distributed via regional power grids to millions of residents, rural communities, tribal lands, and municipal areas across the American Southwest.

Impacts of Low Water Levels on Power Generation

Low water levels generally threaten electricity generation at dams along the river. The current lowest water level at Lake mead & Lake Powell along the Colorado River significantly affects power generation. The low water levels in Lake Powell and Lake Mead reduce the head pressure needed to spin hydroelectric turbines. This cuts total electricity output from major facilities like Glen Canyon Dam and Hoover Dam, threatening cheap peak energy for the western grid and forcing utilities to source costly replacement power.
• Lower Output Capacity: Reduced water volume and lower surface elevations decrease the force and flow through the dam turbines.
• Approaching Minimum Power Pools: Lake Powell is nearing the critical elevation threshold where water drops too low for turbines to function, threatening a complete halt to its hydropower generation.
• Reduced Flexibility: Hydropower plants act as fast-responding resources to balance unexpected spikes in grid demand; diminished water levels restrict this crucial grid-regulation capability.

Responses to the Crisis

With the current climate conditions of continuous drought and extreme heat in the US Southwest and the projected Super El Niño, an intense warming phase of the equatorial Pacific Ocean, being forming up, future threats to Colorado River’s capacity in hydropower generation are predicted with:
• Shutdown danger: Projections warn the pool could brush critical minimum levels, threatening a total pause in hydropower.
• Grid strain: Losing this facility forces utilities to buy replacement energy, which can raise electric bills.
In response to the crisis, the federal government has finalized a new plan for managing the shrinking Colorado River, ordering water cuts for three Western states while seeking cooperation from four others. The Department of the Interior (DOI) set new operating guidelines to reduce Colorado River deliveries to Arizona, California and Nevada by a combined 1.25 million acre-feet a year in 2027 and 2028. The plan is designed to protect the river system and keep critical reservoirs and infrastructure operating as drought continues to push water levels to historic lows.
At individual customer level, the utility bill will increase due to reduced cheap hydroelectric generation at the two major dams because utilities are forced to buy costlier fossil-fuel or market power to meet peak demand, as we customers are experiencing the prolonged heatwaves and in need for running air conditioning and other cooling equipment by longer hours. CIEDM is calling for smart approaches to summer cooling so as to reduce the grid loads and costs.