Rivers provide our communities with economic, ecological, and cultural value. They were our first highways, bringing explorers into the heart of the continent. Today, our rivers are still essential to our day-to-day lives.
There are roughly 3.5 million miles of rivers and tributaries in the United States, connecting us to the sea, even if we live far inland. River habitats vary from high, stony streams, flowing channels for ships and boats, to shallow wetlands. Rivers have striking regional differences that create distinct habitats. Compare the rapid, rocky Colorado to South Carolina’s sleepy, green Santee, or the forested, winding Ohio. A river bed may be stony or soft, lush with underwater vegetation, murky and slow or cold and clear, but each provides an ideal environment for different species and different life stages.
Trout thrive in highland streams, while catfish lurk near the bottom of slow-moving water. Migrating fish, like salmon, must swim up to cooler, stony beds to reproduce. Even the smallest fish play an important role. ”Forage fish” swim upriver to multiply, then head out to sea, providing food for commercially valuable seafood.
Rivers have three distinct habitat areas: river bed, river banks, and the floodplain. The river bed is the water channel itself, while the river banks, called the “riparian zone”, include the land, trees, and water-loving animals and plants along the channel. The low, flat land spreading out from the channel, called the floodplain, periodically floods during heavy rains and snow melt. Sometimes floodplains stay soggy for a long time, creating rich wetland habitat.
Sixty percent of our drinking water comes from American rivers.
Our economy depends on rivers for:
Electricity—generating hydro-electric power.
Transportation—bringing grain, coal, ore, and imports to market.
Recreation and tourism—providing significant economic boost to waterfront areas.
Rivers are home to fish and wildlife:
Freshwater fish like bass, perch, bluegill, and catfish.
Migratory fish such as alewife, salmon, trout, and striped bass.
Many invertebrates that provide food for fish.
Protected, endangered and threatened species.
Floodplains provide calm shallow waters, allowing fish to grow larger before swimming out to sea.
When waters rise floodplains can absorb large amounts of water, providing natural flood control for coastal communities, preventing billions of dollars in damages.
People have harnessed the power of rivers throughout history. We’ve built dams for power and levees for shipping, dredged channels for navigation and canals for irrigation. We’ve built towns and cities along banks and washed their wastes down the stream. These uses can all take a toll on a river’s health.
Dams block migratory fish from returning to their historic spawning grounds, reducing fish populations. Dams also alter the amount of water and sediment traveling downstream, changing living conditions above and below the dam.
Hard shorelines decrease fish populations and increase water velocity, hastening erosion.
Digging channels or straightening rivers destroys nearby floodplains and wetlands, and can lead to development where flooding is inevitable.
Levees may control flooding in one area, but increase flood risk in another. Disconnecting rivers from their floodplain wetlands destroys habitat and increases the risk of extreme flooding and landslides.
Farm runoff containing fertilizers, herbicides, and pesticides contaminates water with toxins and excess nutrients, causing algal blooms and dead zones.
Combined stormwater and sewage systems can overflow and pour untreated human waste into rivers, creating disease risk and adding nutrient pollution. The resulting algae overgrowth can be toxic to fish and people.
Riverside development can reduce shade, which can lead to warmer waters that inhibit reproduction in many species. Hard surfaces also increase pollutant runoff from roadways, parking lots, and roofs.
Overused rivers can run dry long before they reach the sea, destroying important habitat.
Many of our daily habits have a negative impact on the health of our rivers, but there are easy things you can do to make a difference.
NOAA works to protect and restore river habitats through a wide variety of programs and partnerships. We provide scientific expertise to community, state, and partner organizations that monitor water and wildlife. We also provide technical assistance and fund projects that restore healthy habitat. Our process builds community support and attracts multiple sources of funding to ensure ongoing commitment to healthy habitats.
NOAA monitors and studies rivers nationwide to protect vital habitat for a variety of species, including people.
We monitor thousands of river gauges nationwide to make the United States a weather-ready nation. These measuring devices provide timely flood forecasts and warnings that protect life and property.
We collect pre- and post-restoration data on vegetation, soil, water quality, fish population and migration, water levels, and more.
We coordinate with volunteer stream monitors who record data and watch for significant changes.
We provide data including aerial surveys, temperature, nutrient levels, instream flow, and more.
We develop publications and programs for river constituents to learn about habitat health.
Where river habitat has been disrupted by human activity, we work to repair damage and prevent further harm.
We remove barriers to fish migration, like dams, restoring natural conditions to help fish survive and reproduce.
We restore riverbanks and floodplains, reducing erosion and buffering extreme flooding while creating seasonal habitat for wetland creatures.
We reconnect wetlands and estuaries, restoring water movement, improving filtration and providing shelter and food for young fish.
We build consensus, broaden our impact, and leverage our efforts by working with non-profit, academic, corporate, and government partners at every level.
We collaborate with the U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, and state and local organizations to remediate and restore rivers damaged by hazardous waste or oil contamination.
We provide funding to launch restoration projects that engage multiple partners.
We share knowledge, expertise, and advice for best practices.
We conduct research that enhances scientific understanding and provides data to universities, NGOs, and the public.
We offer job skills training and jobs for veterans through conservation corps.
Demolition begins on the Benbow Dam in California.
The Eel River watershed was once the third largest producer of salmon and steelhead in California. Salmon numbers have declined alarmingly since the 1950s. The longest salmon run in the state, the Eel is a high priority for successfully rebuilding salmon stocks. Coho, Chinook salmon and steelhead are all listed on the Endangered Species List.
The NOAA Restoration Center has taken a watershed approach to the Eel River restoration. To do so, we partnered with Humboldt County Resource Conservation District, Ducks Unlimited, California Department of Fish and Wildlife, the California Conservation Corps, the Eel River Watershed Improvement Group, Mendocino Redwood Company, Pacific Watershed Associates, and other regional and local groups.
Together, we have met these major restoration goals:
Restored 400 acres of estuary habitats. The Salt River Ecosystem Restoration project restored seven miles of river channel near the mouth of the Eel River. Over 380 acres of salt marsh was restored and native riparian vegetation was planted along the streamsides. The project significantly reduced flooding of homes and farms in Ferndale, CA, and now provides essential rearing habitat for threatened salmon and steelhead.
Removed the Benbow Dam, opening up 98 miles of spawning grounds. In 2016, NOAA and California State Parks removed the Benbow Dam, improving access to over 98 miles of high-quality habitat. California’s second largest dam removal improved public safety and liability for the state.
Improved spawning and rearing habitat in the Eel River headwaters. In several major tributaries, sediment sources have been addressed by decommissioning dirt roads that are no longer needed. In-stream habitat has been improved by strategically placing large wood in the channel to improve pool habitat, cover, and gravel sorting.
As a result of these efforts, NOAA has documented increased numbers of juvenile salmon and steelhead trout using the estuary, which improves their survival in the ocean. That helps insure that they grow up and come back to their spawning habitat. Access to more spawning habitat and more sheltered, shaded streamsides in the higher tributaries means more spawning and rearing habitat. NOAA will continue to focus on additional high-priority actions to improve habitat in the Eel River, and support a healthy population of wild fish.
Eel River Watershed Overview for California Coastal Chinook Salmon
VIDEO: Benbow Dam Removal
Salt River Ecosystem Restoration Project
Eel River Watershed Overview for CC Chinook Salmon
The NOAA Hydropower Program works with partners including other federal agencies, industry, states, non-governmental organizations, and Tribes to identify and implement solutions to reopen rivers to migratory fish while preserving hydropower generation. See contact list of NOAA Hydropower Coordinators for more information. Through these actions, NOAA aids in the recovery of threatened and endangered species and contributes to the sustainability of economically important commercial and recreational fisheries by making previously blocked upstream habitat accessible allowing fish to breed and complete their life cycles.
Santee Dam on the Santee River in South Carolina. Photo: SC DNR.
The Santee River Basin, in North and South Carolina, currently supports some of the largest populations of migratory fishes on the east coast of the United States, yet population levels remain depleted compared to historical levels. Several fish species in the southeastern U.S. including endangered sturgeon, eels, and river herring, face threats including barriers to migration, poor water quality, habitat loss, and competition from invasive species. To address the threats to these fish species, NOAA worked with the U.S. Fish and Wildlife Service and resource agencies in the states of North Carolina and South Carolina to develop the Santee Basin Restoration Plan. This plan takes a unique approach toward restoring migratory fish by planning for the entire watershed rather than addressing one project at a time. A basin or watershed plan offers an opportunity for management agencies to coordinate restoration activities, balance competing needs in the watershed, and maximize funding for mutual restoration priorities. The Santee Basin Plan provides several objectives to improve fish habitats including: improving water quality, increasing river flows, providing fish passage, and enhancing monitoring.
Barriers to Fish Migration
Improving Fish Migration at Hydropower Dams
Technical Memorandum: Federal Interagency Nature‐like Fishway Passage Design Guidelines for Atlantic Coast Diadromous Fishes (PDF, 52 pages)