The Lake Pend Oreille, Pend Oreille River, Priest Lake and Priest River Commission is charged with studying, investigating, and selecting ways and means of controlling the water quality and water quantity as they relate to waters of Lake Pend Oreille, Pend Oreille River, Priest Lake and Priest River for the communities’ interests and the interests of the State of Idaho and for the survival of the native species fish contiguous to the Pend Oreille/Priest River Basin.

Lake Levels:

Pend Oreille Lake Levels: The Commission was formed in part to help manage the lake level on Lake Pend Oreille.  The Albeni Falls Dam, located in Oldtown, Idaho, controls the top 11.5 feet of Lake Pend Oreille.  Albeni Falls Dam is a federally operated project managed by the U.S. Army Corps of Engineers and power generated from the Dam is marketed by the Bonneville Power Administration. The top 11.5 feet of the lake is used as a reservoir and can be manipulated with certain restrictions for power generation, recreation, fish and wildlife needs, and flood control.  The Pend Oreille Basin holds a lot of water that has huge economic benefit downstream when released at desirable times.  There are numerous pressures on the waters of Pend Oreille and balancing all the desired uses is complex and challenging.

The summer lake level is generally held at 2062′ to 2062.5′ above sea level for recreation.  Most years the spring runoff controls the lake levels through May and June and then the Dam can manage the summer level after the high flows recede.  The summer level must be reached by July 4th, but is often reached by mid to late June. The lake level should not rise above 2056′ before April 30, for flood prevention, and it has typically been held at the summer level until mid-September when it begins the winter drawdown.  

Fall lake levels are currently the center of much discussion. According the Water Control Manual for Lake Pend Oreille the lake can begin drafting on September 1 with a maximum drawdown to 2060′ by September 30.  Over the last fifteen years the lake has typically been held at the summer level until mid-September to benefit recreation with a one to two foot drawdown by September 30.  The speed of the drawdown in the second half of September has been based off of the minimum control elevation (MCE) chosen for the winter.  The winter pool needs to be reached by the second week in November so that shoreline kokanee spawners are not left high and dry.  

The winter lake level is typically at 2051′ although it could potentially fall anywhere between 2051′ and 2056′ according to the Water Control Manual for Albeni Falls Dam.   As of the winter of ’11-’12, the lake level can fluctuate from 2051′ to 2056′, but never fall below the MCE, to allow for increased power generation.  The Lakes Commission continues to be opposed to the fluctuation as the ecological impacts are not fully understood and there is no protection for shoreline landowners whose in water structures may be damaged by the fluctuation.

In 2014, the Army Corps and the State of Idaho reached an agreement that will bring more certainty to the recreational season on Pend Oreille.  Typically the lake will stay at full pool through the third weekend in September or September 18, whichever is later.  The pool can then be drawn down one foot by the fourth weekend or the 25th of September. The agreement also clarifies operations and rational behind these operations for the other seasons.  To view the entire agreement please click here.

Click here for a chart showing the current level of Lake Pend Oreille.  Once you get to the link you will click the “Pend Oreille River Basin” link in the left column and then click “Hope” to see the lake levels at Hope.

Priest Lake Lake Levels: The elevation of the surface of Priest Lake is around 2,440 feet above sea level. The lake levels are controlled by Outlet Dam which is managed by the Idaho Department of Water Resources. The summer level is managed primarily for recreation and in early October the water is rapidly dropped about three feet to get it down before kokanee begin spawning.  The water is held down for flood control until water flows have slowed and then it is raised to the summer elevation.

The low snowpack, hot temperatures, low humidity, and lack of precipitation made for a stressful 2015 for Priest Lake.  Early in July it became apparent that it might become difficult to hold the lake to the typical summer pool.  There were fears that all flows from the lake would need to be shut down into the river in attempt of maintaining the summer pool.  Flows to the river did get very low, but luckily they never needed to be stopped completely.  This predicament did reveal issues that will need to be remedied in the future management of Priest Lake.  The Idaho Department of Water Resources received $300,000 this year to invest in a number of studies in the Priest watershed.  The initial study will evaluate the condition of the dam structure and the possibility of altering the structure.  The second study will evaluate possible impacts around the lake from extra water being held back in anticipation of drought conditions.  The third study will evaluate how to best replace the Priest Lake Thorofare breakwater structure to best keep the channel open to motorized traffic while also limiting the need for continued dredging.  There will be a number of public meetings at Priest Lake on these studies over the course of the summer.

Predation and Other Fishery Issues:

Priest Lake: The Idaho Department of Fish and Game (IDFG) has been wrapping up studies on the Priest Lake fishery which should help them make a management decision in 2018.  The agency has been removing lake trout from Upper Priest Lake for over six years which is an expensive undertaking.  IDFG is trying to decide whether to suppress lake trout in both lakes with the goal of reestablishing a healthy native fishery or to stop suppression efforts in both lakes allowing the lake trout to dominate the whole system.  A essential part to this process is the formation of the Priest Lake Fishery Advisory Committee.  This group is made up of Priest Lake anglers with diverse desires and was assembled by IDFG to help in the future management decision.

IDFG gave an update on the Priest Lake studies at the September 17, 2015 board meeting.  Please click here to see that PowerPoint presentation.

Lake Trout from Lake Pend Oreille

Dr. Mike Hansen with a lake trout on LPO

Pend Oreille: The Commission has been a long supporter of the lake trout suppression efforts on Lake Pend Oreille, including the bounty program, in regard to its potential to reduce the predator trout, relieving the burden and threats to kokanee and bull trout.

Aquatic Invasive Species:

Invasive organisms are typically non-native and have been introduced to a system that lacks the natural controls that existed in it’s home environment.  The controlling factors in the native system could have been predators, a limiting nutrient or mineral, seasonal conditions, or something else. Without these controlling factors invasive organisms will expand aggressively tending to form monocultures that reduce biodiversity and offer little benefit to their environment.

Eurasian watermilfoil

Eurasian watermilfoil (EWM) forms dense monocultures that mat up on the surface of the water inhibiting recreation and degrading habitat. EWM can spread from very small fragments that break free or are cut off from propellers or waterfowl.

Aquatic invasive species (AIS) are a constant threat to our waterways. They impact the ecology of a waterbody, they are extremely expensive to manage once they invade, and they limit the recreational activities we covet here in the Inland Northwest. Prevention is the least expensive method for managing AIS, but in the Pend Oreille Basin we already have some invaders that require management to preserve our quality of life on the water.

Lake Pend Oreille and the Pend Oreille River is infested with Eurasian milfoil, curly-leaf pondweed, and flowering rush.  There is an infestation of Asian clams in Ellisport Bay which has potential to expand or be transported via boat to another part of the lake.  There is an invasive crayfish that has spread down from the Clark Fork River.

Curlyleaf pondweed has distinct lasagna looking leaves. It spreads by hardy seed pods called turions that fall off the plants early towards the middle of the summer.

Curlyleaf pondweed has distinct lasagna looking leaves. It spreads by hardy seed pods called turions that fall off the plants early towards the middle of the summer.

Priest Lake has small infestations of Eurasian milfoil and curly-leaf pondweed.  There is also a population of Chinese mystery snails which are typically released into aquatic ecosystems by dumping of aquariums.  The Priest River substrate is covered in many areas with a diatom called didymo or rock snot.  Didymo looks and feels like wet toilet paper.  It is now believed that Didymo is a native organism that has begun to act aggressively in some circumstances.

The scariest of all known AIS threatening our region are zebra and quagga mussels.  These organisms have not yet been found in any waters of the Columbia River system, but every year they are found in new waterbodies across the U.S. and we need to work diligently to keep them out of our waterways.

Flowering rush plant

Flowering rush is a relatively new invader spreading down from Flathead Lake where it has been established for decades. This plant aggressively fills in bays where it becomes a huge navigation issue as it surfaces and forms a carpet in mid-summer. Flowering rush has a distinct triangular stem and a dense rhizome structure. New plants can grow from small pieces of rhizome which readily break off when disturbed.

Zebra and quagga mussels are freshwater bivalves that differ from native mussels because they attach to surfaces.  None of the native mussels in our region attach to surfaces and it is this characteristic that makes zebra and quagga mussels such a nuisance.  Their larvae, called veligers, are free floating, microscopic and can be carried in water (or your bilge water) for up to eight weeks.   They encrust hard surfaces causing severe and costly damage to hydropower facilities, water treatment plants, wastewater facilities, irrigation intakes, boats and docks.  They are filter feeders consuming the bottom of the food chain which can eventually devastate an entire fishery.  They cover rocky beaches with their sharp shells and smell when they die and rot by the millions on the shoreline.

Zebra and quagga mussels first invaded the Great Lakes in the 1980s and their impacts continue to grow in unpredictable ways.  They were first found in the west in 2007 at Lake Mead and since then have been found in many southwestern waterbodies.  Each year hundreds of boats travel up from these southern lakes to our waters!

Don't move a mussel!

Don’t move a mussel!: The Commission is very active in the community on aquatic invasive species issues and outreach.  The Commission works to spread aquatic invasive species information throughout the Basin aiding in the battle to keep our waterways free of new invaders.

It is essential that we all work together to stop the spread of aquatic invasive species!  Most of these species are spread through boats traveling from one waterbody to another.  They can be attached to the boat, hanging off the boat, or even in the bilge or other standing water in a boat.  Some of invasive species can be microscopic and some can live for months out of the water.  There are a number of things that you can do to help stop this spread.

  •  Clean, Drain and Dry your boat, trailer, fishing gear, life jackets, waders…
  •  Stop at the Boat Inspection Stations that are set up around Idaho and it’s neighboring states.
  •  Spread the word!  Tell your friends and people using our waters about aquatic invasive species and how they threaten our way of life.

Delta Restoration: The Commission is supportive of the restoration work done on the Pack River Delta and is a strong advocate for the ongoing work in the Clark Fork Delta.  Albeni Falls Dam holds the level of Lake Pend Oreille unnaturally high in the summer months.  This inundation of water allows for excellent access to lake waters for recreation, but it has adverse impacts on natural delta processes.  In the natural system, spring flood waters would bring woody debris and sediment down river depositing them in the delta.  These high waters also brought nutrients for growing vegetation and fry emerging from their redds.  The vegetation would grow as the waters receded through the summer creating a healthy island habitat and retaining a clear water channel.

At the Pack River there are still high spring flows that bring sediment and woody debris to the delta, but the vegetation that once preserved the islands has mostly died over the years from being submerged through the entire growing season.  Without vegetative roots holding the islands together the sediment erodes away with the retreating waters each fall.  This has created open water in the summer and mudflats in the winter where there was once rich delta habitat for wildlife and waterfowl.  The main goals  of the Pack River Delta restoration were to build up the remaining islands so that vegetation could grow through the summer, creating structure that would encourage woody debris and sediment deposit to expand on the island growth and creation of  a more clear river channel.

The Clark Fork Delta faces similar challenges as the Pack plus more.  The Clark Fork Delta gets pounded by significant wave action by winds coming from the south.  This is a constant pressure eating away at this delta from the front.  The Clark Fork River also has three dams upstream of the delta that change water patterns and hold back the majority of the sediment and woody debris that would naturally replenish the delta.  It is also a larger system with higher flows.  The first goal of the Clark Fork delta restoration is to create protection for the delta from wave action.  This project is scheduled to begin in the fall of 2014.

Mining: The Commission reviewed the plans for the proposed Rock Creek Mine in 2005 and after community meetings and visits from the developer, took a position in opposition of the Mine.  In 2015 the Rock Creek Mine was bought by Hecla Mining.  To read more about the current status of the mine and permitting process please take a look at this newsletter article “Rock Creek Mine Basics.”  More recently Hecla also announced that is acquiring Mines Management including the Montanore project that would mine the same deposit as Rock Creek, but from the Kootenai watershed side.

Planning and Zoning: Land use planning is the most comprehensive tool we have locally and nationally to influence our economy and sustain our natural resources, which are mutually dependent.  Our land uses are essential and many: agriculture, housing, water supply, waste disposal, wildlife habitat, forestry, recreation, commercial production and transportation.

All land uses have the potential to impact water quality or quantity.  As an advisory board to Idaho on water issues in the Pend Oreille Basin, we follow land use planning decisions closely.  This year, Bonner County has made a number of changes to the land use ordinances and policies. If you are interested in following these changes, as they occur, please look at the Bonner County Commissioners regular meeting agendas posted on their website at on Fridays.

Discharge Concerns: Wastewater treatment plants and sewer districts often discharge to surface waters. The Commission generally discourages this practice, as Lake Pend Oreille is already documented as being impaired due to an excessive amount of nutrients. Source pollution, such as municipal dischargers, are part of the issue, but so is “non-point source pollution,” that is spread out over a large portion of land and not limited to a single source. This non-point source pollution is of utmost concern, and remedies include working with cities, municipalities, and shoreline homeowners to employ Best Management Practices, use proper stormwater and erosion measures, etc. in order to curb nutrient loading.

Spokane Valley-Rathdrum Prairie Aquifer

Spokane Valley-Rathdrum Prairie Aquifer

Spokane Valley-Rathdrum Prairie Aquifer: The Aquifer supplies drinking water to over one-half a million people in the region; it is of utmost concern that we protect this precious resource.




Blue-green algae bloom Hayden Lake 2015

Blue-green algae bloom Hayden Lake 2015

Blue-Green Algae Blooms: Blue green algae blooms sparked health advisories at Fernan, Avondale and Hayden Lakes in the summer of 2015 .  Blue green algae is a common term for cyanobacteria which are part of the phytoplankton layer in most lakes.  Cyanobacteria can reproduce quickly leading to a bloom due to high air and water temperatures, available nutrients such as phosphorus and nitrogen, and sunlight.  Some cyanobacteria produce toxins that are released when they die and these toxins can be pose a potential health threat to people or animals that consume or inhale water hosting a bloom.

Always keep an eye out for water that is an uncharacteristic color or where green mats have formed on the water.  If you see something suspect please call the Idaho Department of Environmental Quality at 208-769-1422 or the Panhandle Health District at 208-415-5220.