Clearwater River at Lewiston

Lewiston, Idaho

SWIMMING IS UNADVISABLE DUE TO HIGH WATER LEVELS AND UNSAFE RUNOFF

The Clearwater River is a 74.8-mile-long (120.4 km) river in north central Idaho, which flows westward from the Bitterroot Mountains along the Idaho-Montana border, and joins the Snake River at Lewiston. In October 1805, the Lewis and Clark Expedition descended the Clearwater River in dugout canoes, putting in at "Canoe Camp," five miles (8 km) downstream from Orofino.

By average discharge, the Clearwater River is the largest tributary of the Snake River. The River got its name for the Niimiipuutímt naming as Koos-Koos-Kai-Kai - “clear water”.

The drainage basin of the Clearwater River is 9,645 square miles (24,980 km2). Its mean annual discharge is 15,300 cubic feet per second (430 m3/s).

WATER QUALITY
  • Met water quality standards less than 60% of the time
  • Historical Status
  • This status is based on the latest sample, taken on . Snake River Waterkeeper updates the status of this beach as soon as test results become available. These results were posted to Swim Guide on at
For water quality icon legend, click:   
CURRENT WEATHER
13°C
Mostly clear
MONITORING FREQUENCY

Clearwater River at Lewiston is sampled from June 7th to August 30th

SOURCE INFORMATION

There is currently very limited water quality monitoring of Idaho's inland swim sites. The federal Beach Act does not cover freshwater or riverine beaches, and states in the Basin do not monitor Snake River swimming beaches or recreational access sites.

As part of its Water Quality Program, Snake River Waterkeeper monitors water quality at more than 100 sites on the Snake River and its tributaries for temperature, dissolved oxygen, pH, salinity/conductivity/total dissolved solids, ammonia, and nitrates. Data are collected at sample sites June-October and assigned safety ratings based on comparison to EPA's Recreational Water Quality Criteria for Human Health:

pH: 5 – 9 µg/L
Salinity/Conductivity/Total Dissolved Solids: 500 mg/L
Nitrates: 10 mg/L

A site is marked Green when single sample results meet all Human Health Criteria.
A site is marked Red when the results are equal to or above Human Health Criteria.
A site is marked Grey when there are no current results or no available information.
Sites found to exceed EPA's Aquatic Health Criteria are noted in site descriptions.

While criteria measured are useful indicators of contamination, there are many other potential sources of pollution that are not reflected in our Swim Guide, including E.coli and other bacteria, heavy metals, pharmaceuticals, fertilizers, and pesticides that harm aquatic life.

Download the free app for smartphone and learn about Swim Guide 3.0 at www.theswimguide.org. To learn more about our efforts to protect and restore the Snake River's water quality, visit www.snakeriverwaterkeeper.org.

WATER QUALITY GRAPH

Clearwater River at Lewiston

Lewiston, Idaho

WATER QUALITY
  • Met water quality standards less than 60% of the time
  • Historical Status
  • This status is based on the latest sample, taken on . Snake River Waterkeeper updates the status of this beach as soon as test results become available. These results were posted to Swim Guide on at
For water quality icon legend, click:   
CURRENT WEATHER
13°C
Mostly clear

SWIMMING IS UNADVISABLE DUE TO HIGH WATER LEVELS AND UNSAFE RUNOFF

The Clearwater River is a 74.8-mile-long (120.4 km) river in north central Idaho, which flows westward from the Bitterroot Mountains along the Idaho-Montana border, and joins the Snake River at Lewiston. In October 1805, the Lewis and Clark Expedition descended the Clearwater River in dugout canoes, putting in at "Canoe Camp," five miles (8 km) downstream from Orofino.

By average discharge, the Clearwater River is the largest tributary of the Snake River. The River got its name for the Niimiipuutímt naming as Koos-Koos-Kai-Kai - “clear water”.

The drainage basin of the Clearwater River is 9,645 square miles (24,980 km2). Its mean annual discharge is 15,300 cubic feet per second (430 m3/s).

MONITORING FREQUENCY

Clearwater River at Lewiston is sampled from June 7th to August 30th

SOURCE INFORMATION

There is currently very limited water quality monitoring of Idaho's inland swim sites. The federal Beach Act does not cover freshwater or riverine beaches, and states in the Basin do not monitor Snake River swimming beaches or recreational access sites.

As part of its Water Quality Program, Snake River Waterkeeper monitors water quality at more than 100 sites on the Snake River and its tributaries for temperature, dissolved oxygen, pH, salinity/conductivity/total dissolved solids, ammonia, and nitrates. Data are collected at sample sites June-October and assigned safety ratings based on comparison to EPA's Recreational Water Quality Criteria for Human Health:

pH: 5 – 9 µg/L
Salinity/Conductivity/Total Dissolved Solids: 500 mg/L
Nitrates: 10 mg/L

A site is marked Green when single sample results meet all Human Health Criteria.
A site is marked Red when the results are equal to or above Human Health Criteria.
A site is marked Grey when there are no current results or no available information.
Sites found to exceed EPA's Aquatic Health Criteria are noted in site descriptions.

While criteria measured are useful indicators of contamination, there are many other potential sources of pollution that are not reflected in our Swim Guide, including E.coli and other bacteria, heavy metals, pharmaceuticals, fertilizers, and pesticides that harm aquatic life.

Download the free app for smartphone and learn about Swim Guide 3.0 at www.theswimguide.org. To learn more about our efforts to protect and restore the Snake River's water quality, visit www.snakeriverwaterkeeper.org.

WATER QUALITY GRAPH



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