Water Quality

A small brown fish against a sandy bed
The desert pupfish in Death Valley National Park need a certain chemical composition of groundwater to survive.

NPS Photo

What Happens Upstream Matters!

Water alone is not enough; quality matters too. Quality is not only important for human uses such as drinking water and swimming, but also for the flora and fauna that call those waters home. They, too, need clean water to survive.

Water Quality Effects

Although transparent, water isn’t always clean! As water moves throughout an ecosystem, it can become exposed to different substances that can alter the quality of water. When water quality is degraded, it can cause things like:

  • Closures due to harmful algal blooms

  • Fish consumption advisories

  • Swimming restrictions due to pathogens

  • Expensive treatment to meet drinking standards

Impairments

Some substances in the water column occur naturally. Water sources can pick up nutrients from decaying matter, or carry certain minerals from rock that waters interact with. But some substances occur unnaturally, or can be exacerbated by human influence. For example, too much nutrients in the water column from fertilizer use can cause algal blooms. Pharmaceuticals can enter our waterways from the flushing or improper disposal of medication.

Man holding jar filled with brown tinted water
Sediment can enter the water column following a fire, like this one after the Gibbon Canyon fires in Yellowstone National Park.

NPS Photo

Possible impairments in water are:

Monitoring Change

The National Park Service supports the Clean Water Act and the Safe Drinking Water Act by monitoring and researching impairments and potential impacts to park waters, and routinely tests park water supplies for potability. Water quality is measured as a vital sign for park units, which helps to indicate the overall health or condition of a resource; in this case, "Is the water healthy?" Discover the ways we monitor water quality below.


From the field

Showing results 1-10 of 147

  • Cuyahoga Valley National Park

    Creating Cuyahoga Valley National Park: 50 Moments That Tell the Story

    • Locations: Cuyahoga Valley National Park
    A runner follows a flat trail along a waterway through foggy, autumn trees.

    In honor of our 50th anniversary year in 2025, Cuyahoga Valley National Park is highlighting 50 key events that help define who and what we are. They showcase the many partners that have come together to preserve open space, create opportunities for recreation, clean up pollution, restore habitats, and save historic resources.

  • Natural Resource Stewardship and Science Directorate

    Teaming Up for Science

    • Offices: Natural Resource Stewardship and Science Directorate
    two women sit on sandy area and catalog dragonfly larvae into plastic bags and containers

    A new partnership began in October 2021 and supports science and stewardship activities that benefit both parks and their local communities. Over the next five years parks and their communities will collaborate to identify and address their scientific priorities. Projects in the first year will focus on water quality, marine biodiversity, and preservation of night skies.

  • Acadia National Park

    A New Way to Gauge Risk of Toxic Blooms in a National Park

    • Locations: Acadia National Park
    Scenic lake on an overcast day, backed by rocky and tree-covered, rounded mountains.

    Harmful algal blooms endanger drinking water sources and aquatic life but are notoriously hard to study and manage. We created a “scorecard” to assess the likelihood of toxic blooms. It can help water managers focus on the most effective actions.

  • Stream by Stream: Researching and Protecting Cuyahoga Valley National Park’s Vital Waterways

    • Locations: Cuyahoga Valley National Park
    • Offices: Heartland Inventory & Monitoring Network, Inventory and Monitoring Division
    A small stream flowing through an area with trees and dense vegetation.

    At Cuyahoga Valley National Park, an inventory of streams and their inhabitants is helping park managers understand and protect these vital waterways. The study revealed that most streams in the park are in good condition with minimal habitat damage. For the few streams facing challenges, conservation and restoration initiatives will help restore them to high ecological quality.

  • Pharmaceuticals, Personal Care Products, and Pesticides in Park Waters

    Three people talking on a beach, two of them wearing transparent plastic sleeves

    Scientists tested water samples from 46 national parks in the largest study of its kind.

  • I Didn't Know That!: Keeping Rivers Wild

    a calm river

    Building rock dams or digging new river channels may seem like harmless fun, but they can affect the flow and quality of the water, even well upstream. Find out how you can help keep rivers wild.

  • I&M Water Quality Data Helps Cumberland Gap National Historical Park Address Aging Infrastructure

    • Locations: Cumberland Gap National Historical Park
    • Offices: Cumberland Piedmont Inventory & Monitoring Network, Inventory and Monitoring Division, Natural Resources Stewardship & Science
    A person crouches to collect water from a small stream in a vial.

    In 2008, scientists from the Cumberland Piedmont Network found a concerning trend: E. coli levels were too high. The source needed to be identified and addressed for the health and safety of the thousands of humans and animals that enjoyed the park. The network's long-term water quality monitoring program not only helped to identify the issue, but it also provided the tools to evaluate the solution.

  • Water Quality in the Northern Colorado Plateau Network: Water Years 2019-2022

    • Locations: Arches National Park, Bryce Canyon National Park, Canyonlands National Park, Capitol Reef National Park, Dinosaur National Monument,
    • Offices: Inventory and Monitoring Division, Northern Colorado Plateau Inventory & Monitoring Network
    A calm river flows through a red rock canyon on a sunny summer day.

    Good, clean water is essential for healthy ecosystems--for people, vegetation, and animals--making it one of the most important resources in the semi-arid west. The Northern Colorado Plateau Network and its partners monitor water quality in 8 national parks in Utah and Colorado to help scientists and managers conserve these resources. This article summarizes 2019-2022 water quality data and how they compare to state standards.

  • Bighorn Canyon National Recreation Area

    Series: Water Resources Monitoring in the Bighorn River near Fort Smith, Montana, 2019

    • Type: Series
    • Locations: Bighorn Canyon National Recreation Area
    Two boats on the side of a blue river lined by green plants and a few trees

    The Greater Yellowstone Network monitors water quality and analyzes river discharge in the Bighorn River near Fort Smith, MT, each year. This sampling location in Bighorn Canyon National Recreation Area is just downstream of the Yellowtail Afterbay Dam. Water quality is relatively good at this location. We will update this site each year as new information is collected.

  • Bighorn Canyon National Recreation Area

    Series: Water Resources Monitoring in the Bighorn River at Kane, Wyoming, 2019

    • Type: Series
    • Locations: Bighorn Canyon National Recreation Area
    A bend in a river lined by rocky shores and dirt banks with mountains in the distance.

    The Greater Yellowstone Network monitors water quality and analyzes river discharge in the Bighorn River at Kane, Wyoming, each year. The Bighorn River watershed contains 16 impaired stream segments downstream of Boysen Reservoir and upstream of Bighorn Lake. We present results of our monitoring and links to data from previous years in this series. We will update this site as new information is collected.

Tags: water quality water quality monitoring clean water
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Last updated: August 13, 2024

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