Water Quality Improvement Projects
Pend Oreille River Area
The Pend Oreille River begins at the outlet of Lake Pend Oreille in
northern Idaho and is part of the Clark Fork-Pend Oreille Basin, which
drains western Montana and northern Idaho. The river enters Washington
State near the city of Newport and flows 72 miles north through the
Kalispel Tribe of Indians' reservation to the Canadian border. After
flowing about 15 miles in British Columbia,
Canada, the Pend Oreille River joins the Columbia River. The Pend Oreille contributes approximately 10% to
the total flow of the Columbia River.
There are two hydroelectric projects on the Pend Oreille River in
- Box Canyon Dam is owned and operated by the Pend Oreille Public Utility District.
Box Canyon Dam received a new
Federal Energy Regulatory Commission (FERC) license in 2005. For
more information please see their web site: www.popud.com/license.htm.
- Boundary Dam is owned and operated by Seattle City Light, which is in the process of relicensing
Boundary Dam. You can obtain additional information from Seattle
City Light’s web site:
Two other dams influence the Pend Oreille River in Washington State.
Albeni Falls Dam is located just upstream of the Washington-Idaho state
line in The U.S. Army Corps of Engineers owns and operates Albeni Falls
Dam, which controls
river flows in Washington. Another major dam in the basin is Cabinet Gorge Dam,
which is located upstream of Lake Pend Oreille.
Water quality issues
The Pend Oreille River does not meet Washington State’s
water quality standards. As a
result, Ecology listed the Pend Oreille River on the 1998 list of
impaired water bodies (also called the 303[d] list)
because it did not meet temperature and total dissolved gas (TDG)
water quality standards. On the
2004 Category 5 303(d)
list, the Pend Oreille River is also listed for Aldrin, pH and total
PCBs. Some tributaries to the Pend Oreille River are also listed
for fecal coliform bacteria, dissolved oxygen, and temperature.
Why this matters
When water temperatures are too high it can make the streams
uninhabitable for fish and other aquatic animals. Many salmon and trout
species will suffer a variety of ill effects, ranging from decreased
spawning success to death, when waters are too warm. The optimal
temperature for most salmon and trout species is between 12-14˚C
(54-57˚F), and temperatures in the range of 23-25˚C (73-77˚ F) can be
lethal, depending on the species.
Water temperature can also affect how much oxygen is dissolved in
the water. Fish need this dissolved oxygen (DO) to breathe. The
warmer the water the less DO it can hold. The warmer temperatures also tend to
speed up the metabolism of the fish so that they require more oxygen for biological
Total dissolved gas is air that gets trapped in water as a
result of waterfalls or water plunging over a dam. When rivers have excess total
dissolved gas, the gas can form bubbles inside the fish, often in the eyes or
near fins. This condition is known as gas bubble disease and can be fatal.
Chemicals such as aldrin and PCBs can build up in fish. If the level
of chemicals in the fish is high enough, it can become unsafe for people to eat
a large amount of the fish.
For more information, please see our
Importance of the Different Impairments page.
Status of the projects
Beginning in 2004, Ecology has worked to develop two TMDLs for the Pend Oreille River: Total Dissolved Gas and Temperature.
Since 2005, Ecology has coordinated with the Environmental Protection
Agency (EPA), the Kalispel Tribe, the Idaho Department of Environmental
Quality (IDEQ), and the Tri-State Water Quality Council to evaluate
water temperature throughout the basin.
The agencies have worked with a watershed advisory group (WAG). The WAG is
made up of citizens, cities, organizations, and businesses in the watershed. In August 2007, the WAG reviewed the first draft of the TMDL. WAG
members had numerous comments and concerns about the technical analysis.
As a result, from the summer of 2008 to early fall of 2010, Ecology worked to address concerns
and edit the draft TMDL.
During this time, Ecology also held meetings with the agencies and sent updates to
Ecology held a public comment period for the
temperature TMDL from October 1 -
November 30, 2010. A public meeting was held on October 14, 2010 at the Pend
Oreille Public Utility District office in Newport, WA. Ecology received ten
comment letters, which you can read in full text by clicking on one of the links
in the table that follows. From December 2010 until
March 2011, Ecology worked to respond to the comments and edit the TMDL. Ecology
sent the final TMDL to EPA for approval on April 6, 2011.
See the Technical information page for
additional information about the TMDL.
On April 28, 2011, the Department of Ecology received a letter from Seattle
City Light requesting Ecology to initiate a
process in response to the TMDL submittal. The Pend Oreille County PUD
initiated a similar request on May 6, 2011.
Total Dissolved Gas TMDL
On March 26, 2008, the
Environmental Protection Agency (EPA) approved the
Total Dissolved Gas TMDL for the
Washington portion of the Pend Oreille River. The next step is
to develop a water quality implementation plan. The implementation plan
is on hold until the temperature TMDL is completed so that only one
plan, covering both parameters, will be written. Implementation of this TMDL will reduce the amount of air trapped
in the water due to operating dams on the river in Washington.
Idaho Dept. of Environmental Quality’s web site for the Pend Oreille TMDL
WRIA 62: Pend Oreille
Watershed Information (Water web site)
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