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Aquatic Weeds

Aquatic Weeds

Aquatic plants represent a healthy component of a lake’s ecosystem, providing food, habitat and spawning grounds for fish and wildlife, as well as contributing to shoreline protection and overall water quality.

However, the introduction of non-native invasive weeds can have negative effects on lakes and rivers. These plants often outcompete the native species and can degrade water quality, destroy habitat, and spoil or reduce recreation opportunities.

As part of the Spokane River Project License, we have developed the following three Aquatic Weed Management Programs: 

  • Lake Spokane and Nine Mile Reservoir Aquatic Weed Management Program
  • Coeur d’Alene Lake Aquatic Weed Management Plan for Non-Tribal Waters
  • Coeur d’Alene Reservation Aquatic Weed Management Plan

The primary elements of these programs include:

  • Educational programs to inform the public of the problems associated with invasive aquatic weeds and how to prevent their spread and introduction into our water bodies. Fragrant Waterlily
  • Monitor and map the distribution of invasive aquatic weeds within designated areas.
  • Develop management strategies to help control invasive aquatic weeds.   

Avista and its partners are working together to control the following invasive weeds at public and community recreation sites on Lake Spokane: Flowering Rush, Eurasian Water Milfoil, Yellow Floating Heart, White Lily, and Curly-leaf Pondweed.

Avista also monitors for invasive aquatic weeds on Nine Mile Reservoir and will work with its partners to develop a plan to  control them if they are found.

In Coeur d’Alene Lake and the lower St. Joe and St. Maries rivers, Avista and its partners are working to control Eurasian Water Milfoil and a hybrid species of milfoil, which are currently the only known invasive aquatic weed species present within the Coeur d’Alene Lake system.

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Aquatic Weeds Pictures

Invasive aquatic plants (weeds) have negative effects on:

  • Recreational uses such as boating, fishing, and swimming. 
  • Fish and wildlife habitat due to the creation of non-native monocultures within water bodies and along the shorelines. 
  • Water quality, in which plant sloughing, leaf turnover, and decomposition of large amounts of plant material at the end of the growing season increase phosphorus and nitrogen in the water column.  Dense mats of aquatic weeds alter water quality by raising the pH, decreasing oxygen under the mats, and increasing temperature. 
  • Aesthetics by creating monocultures and replacing native vegetation, as well as forming mats of decaying plants along shorelines. 

Eurasian Water Milfoil
(Myriophyllum spicatum)

Eurasian Water Milfoil           Eurasian Water Milfoil

 

 

Curly-Leaf Pondweed (Potamogeton crispus)

Curly-Leaf Pondweed

Courtesy of Washington Department of Ecology

 

 

White Lily (Nymphaea odorata) 

White Lily            White Lilies

Yellow Floating Heart (Nymphoides peltata)

Yellow Floating Heart            Yellow Floating Heart

Courtesy of Washington Department of Ecology
 

 

Flowering Rush (Butomus umbellatus)

Flowering Rush 
To help protect our local rivers and lakes from invasive species, here are some tips to remember as you take to the lake or river:

  • Remove all sediment and vegetation from boats, trailers, and fishing gear when traveling between different lakes or rivers. Don’t forget to clean your waders.
  • Wash and dry all boats, trailers, and fishing gear thoroughly between trips.
  • Disinfect gear (especially waders and live wells) if you have been in an area containing aquatic invasive species.
  • Stop at every boat check station in your area.

Remember, it is illegal to transport invasive species and it only takes one mistake to infest a new area.

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Aquatic Weeds Work Plans and Reports

As part of the Spokane River Project License, we are implementing three Aquatic Weed Management Programs in consultation with various regulators, agency partners, and stakeholders. 

Work Plans and Reports associated with each of the three programs include the following:Aquatic Weeds

Lake Spokane and Nine Mile Reservoir Aquatic Weed Management Program 

Regulators, agency partners, and stakeholders – Washington Department of Ecology, Washington Department of Fish and Wildlife, Washington Department of Natural Resources, Washington State Parks, Stevens County Conservation District, Stevens County Noxious Weed Control Board, Spokane County Conservation District, Spokane County Noxious Weed Control Board, Lincoln County Weed Control Board, and the Lake Spokane Association.

2013 Aquatic Weed Summary Report (dated February 28, 2014) 
2012 Aquatic Weed Summary Report (dated February 28, 2013)
2011 Aquatic Weed Summary Report (dated February 27, 2012)
Coeur d’Alene Lake Aquatic Weed Management Plan for Non-Tribal Waters 

Regulators, agency partners, and stakeholders – Coeur d’Alene Tribe, Heyburn State Park, Idaho Department of Environmental Quality, Idaho Department of Fish and Game, Idaho State Department of Agriculture, Kootenai County Noxious Weed Control Board, and the U.S. Fish and Wildlife Service.

2013 Aquatic Weed Annual Summary Report (dated February 28, 2014)
2012 Aquatic Weed Annual Summary Report (dated February 28, 2013)

2011 Aquatic Weed Annual Summary Report (dated February 28, 2012)
Coeur d’Alene Lake Reservation Aquatic Weed Management Plan

Regulators, agency partners, and stakeholders – Coeur d’Alene Tribe and the U.S. Bureau of Indian Affairs.

2012 Aquatic Weed Annual Summary Report (dated March 20, 2013)

2011 Aquatic Weed Annual Summary Report (dated March 28, 2012)
2010 Aquatic Weed Annual Summary Report (dated March 29, 2011)

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Aquatic Weeds Meetings

Avista holds annual meetings, typically in the winter and spring, to gather input and to provide information about implementing the three aquatic weed management programs. These meetings are essential in that they provide information exchanges that often lead to a more common understanding of the current invasive aquatic weed(s) of concern and how to effectively control these weeds in a cost-effective manner. Avista and its partners have also found that by sharing costs and information they can often accomplish more effective weed control programs with limited resources.

The first annual meetings were held in March of 2011, and took place after each program was approved by all the required regulatory agencies.

Lake Spokane and Nine Mile Reservoir  

March 1, 2012 Meeting
March 24, 2011 Meeting

Coeur d’Alene Lake (Waters outside the Coeur d'Alene Reservation)

February 23, 2012 Meeting
March 21, 2011 Meeting

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Aquatic Weeds Correspondence

Communication and correspondence between Avista, its agency partners, regulators, and stakeholders is essential as we implement our three aquatic weed control programs.

The following documents and correspondence are provided for your reference:

Lake Spokane and Nine Mile Reservoir

Avista Letter to FERC Submitting 2013 Summary Report (dated February 28, 2014)
Avista Letters to Ecology, WDFW, and WDNR (dated December 24, 2013)
Avista Letter to FERC Submitting 2012 Summary Report (dated February 28, 2013)
Ecology's Approval of 2012 Summary Report (dated January 29, 2013)
WDFW Letter with Comments on 2012 Summary Report (dated February 1, 2013)
Avista Letters to Ecology, WDFW, and WDNR (dated December 21, 2012)
FERC Order Approving Lake Spokane and Nine Mile Reservoir Aquatic Weed Management Program
Avista Letters to Ecology and WDFW (dated April 29, 2010)
Avista E-mail Revised AWMP to Ecology & WDFW (dated June 7, 2010)
Ecology Approval Letter (dated June 14, 2010)
WDFW Approval E-mail (dated June 11, 2010)
WA DNR E-mail  (dated April 29, 2010)
Avista Letter to FERC (dated June 16, 2010)

Coeur d’Alene Lake (Non-Tribal waters)

Avista Letter to FERC Submitting 2012 Aquatic Weed Annual Report (dated February 28, 2013)
Avista Letters to IDEQ, ISDA, KCNWCB, and CDAT (dated December 21, 2012)
FERC Order Approving Coeur d’Alene Lake Aquatic Weed Management Plan for Non-Tribal Waters
Avista Letters to US FWS and IDFG (dated April 28, 2010)
US FWS Approval Letter (dated June 7, 2010)
IDFG Approval E-mail (dated June 3, 2010)
Avista Letter to FERC (dated June 18, 2010)

Coeur d’Alene Lake (Reservation)

Avista Letter to FERC Submitting 2012 Annual Report (dated March 21, 2013)
Avista Letter to Interior Submitting 2012 Annual Report (dated February 28, 2013)
FERC Order Approving Coeur d’Alene Reservation Aquatic Weed Management Plan
BIA Approval Letter (dated June 17, 2010)
Avista Letter to FERC (dated June 18, 2010)

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Aquatic Weeds Contacts

The regulators, agency partners, and stakeholders that Avista works with and their website information is provided below:

Coeur d’Alene Tribe

Heyburn State Park

Idaho State Department of Agriculture

Idaho Department of Environmental Quality

Idaho Department of Fish and Game

Kootenai County Noxious Weed Control Board

Lake Spokane Association

Lincoln County Weed Control Board

Spokane County Conservation District

Spokane County Noxious Weed Control Board

Stevens County Conservation District

Stevens County Noxious Weed Control Board

U.S. Department of Interior, Bureau of Indian Affairs

U.S. Fish and Wildlife Service

Washington Department of Ecology

Washington Department of Fish and Wildlife

Washington Department of Natural Resources

Washington State Parks

For more information about Avista’s Aquatic Weed Management Programs, please contact:

David Armes
Terrestrial Resource Specialist
Avista Utilities
1411 E. Mission Ave., MSC-1
Spokane, WA 99220-3727
Office: (509) 495-2796
david.armes@avistacorp.com 

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