Update February 12, 2021
By Tobi Tyler, Toiyabe Chapter and Tahoe Area Group ExCom(s) member
The Tahoe Keys Property Owners Association (TKPOA) has applied to the Lahontan Water Board (LWB) and the Tahoe Regional Planning Agency (permitting agencies) for a permit to use aquatic herbicides for the very first time in Lake Tahoe’s waters. The Tahoe Keys lagoon waters have out-of-control invasive aquatic weeds, which have been spreading to other parts of the Lake. Both the weeds and the proposed herbicides threaten the health of the Sierra Nevada's crown jewel and national treasure, Lake Tahoe.
Sign the petition to protect Lake Tahoe from aquatic weeds and herbicides.
The rush to use herbicides with the potential to poison Lake Tahoe seems to be underway without basic questions being answered.
- The original draft environmental document clearly stated that non-chemical methods were environmentally superior alternatives, yet the permitting agencies, the League to Save Lake Tahoe and TKPOA continue to insist that a one-time test with herbicides is needed. Why not give the non-chemical methods a chance? And, if a one-time use is truly the intent, why “test” with herbicides when they will not continue to be used? Do the agencies, League and TKPOA really think a one-time application of herbicides will be effective when this contradicts evidence from everywhere else in the country where these weeds are a problem?
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Consistent with State and Federal antidegradation policies, a complete Antidegradation Analysis (AA) is required as part of the environmental document. Yet this analysis has still not been provided to the public. Where is the degradation analysis critical for justifying herbicide use? Why have we not yet seen it?
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The underlying reason for the weeds is stagnant waters in the Keys lagoons, high nutrient loading from decades of fertilizer use surrounding the lagoons, and stormwater inputs into the lagoons. Why are there no plans to address the underlying causes that could then prevent the use of potentially hazardous herbicides?
The Sierra Club would like to see the above questions answered fully. We would also like to see a revised Draft EIR/EIS, one that includes the anti-degradation analysis, before reaching a decision on the TKPOA permit. The Sierra Club’s primary concern is the health of the Lake. We recommend a physical barrier across the west channel to prevent the weed fragments created by mechanical harvesting by the Tahoe Keys community from spreading into the Lake. The bubble curtain, which failed this last summer for two months at the height of the boating season and caused a huge bloom outside the west channel, is clearly insufficient to prevent weeds from spreading to the Lake.
Nutrients from Tahoe Keys lawns and South Lake Tahoe stormwater have been accumulating in the lagoon waters and bottom sediments and fueling weed growth for 60 years. Herbicides don’t kill the turions and seeds, so the weeds will continue re-sprouting again and again. The weeds in the lagoons have become a self-sustaining ecosystem. To those homeowners frustrated by this continuing weed problem it may appear that the use of chemicals will be a simple solution. Unfortunately, it will likely create even worse problems than are known at this time. The use of herbicides in no way benefits the general public, water quality or the health of the Lake.
Furthermore, the Sierra Club believes that LWB and TRPA need to direct their staff toward a longer-term solution to the Keys’ weeds nightmare – one that actually solves the weed problem instead of just managing it forever, and one that preserves Lake Tahoe’s nationally treasured waters. This solution would be to restore the lagoons to marsh (i.e., the waterways, in particular the dead-end stagnant sections – leaving the houses intact) in order to provide filtration for the nutrient-rich stormwater that runs off the Keys’ lawns, houses and streets as well as the surrounding community. This is the only viable long-term solution to this Lake-threatening Tahoe Keys weeds nightmare.
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On November 19, 2020, the Lahontan Regional Water Control Board considered arguments on whether to allow herbicides -- a decision that could affect the future of Lake Tahoe’s fabled purity and clarity. Your help is needed to protect Lake Tahoe.
On November 19, the Lahontan Water Board will decide whether to permit the first-time-ever application of chemical herbicides in Lake Tahoe to control the spread of Eurasian milfoil and other invasive aquatic weeds. Sierra Club opposes herbicides for several reasons:
- The EPA classifies Lake Tahoe as a Tier III Outstanding National Resource Water, whose purity cannot be degraded longer than weeks or months. Yet everywhere they have been used in this country to control aquatic weeds, herbicides require multiple applications over years and still never eradicate the invasive weeds.
- The Lahontan Water Board’s Basin Plan REQUIRES a thorough evaluation of all available non-chemical methods before using herbicides. This thorough evaluation has not been performed.
- Regulations require that an Anti-Degradation Analysis be completed before herbicides can be applied. The analysis has not been completed.
- Herbicides would not remove the source of the weed problem in the Tahoe Keys, the ongoing nutrient loadings from the surrounding community, which have accumulated in the lagoons for over 60 years.
The Sierra Club will be presenting these arguments and more before the Lahontan Water Board at its 11/19 meeting. Please also commit to speaking on behalf of Lake Tahoe at the meeting.
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We need 8-10 people who will speak in defense of Lake Tahoe. We will follow up with you to make sure you have all the information you need.
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You can also submit written comments. Please send them to Lahontan@waterboards.ca.gov. Make sure to include "Comment on November 19, item #7" in your subject line or first sentence of your email.
(Please click here if you would like background information about this issue.)
Talking point #1
The Lahontan Water Board’s Basin Plan REQUIRES a thorough evaluation of all available non-chemical methods before using herbicides. If the Water Board permits testing herbicides without previous thorough implementation and evaluation of all available non-chemical methods, the Water Board will be violating its own Basin Plan.
Background
The invasive aquatic weed growth in the Tahoe Keys is a huge problem that has been extremely mismanaged for decades by the Tahoe Keys Property Owners Association, TRPA, and the Lahontan Water Board. The agencies have largely ignored the weed problem in the Keys for years. Now, realizing what a serious threat to Lake Tahoe the weeds have become, they want to push the “easy button” and apply herbicides in the Keys lagoons, hoping that herbicides will solve the problem. The Proposed Project of their Control Methods Test (CMT), scheduled for spring 2021, would test herbicides and also test laminar flow aeration [http://restorativelakesciences.com/wp-content/uploads/2013/06/The-Michigan-Riparian-Winter-2012.pdf] and ultraviolet light [https://www.unr.edu/nevada-today/news/2020/tahoe-aquatic-invasive-species] , newer non-chemical methods that have been shown to be effective elsewhere in the Lake. These non-chemical methods, however, have not been thoroughly implemented and evaluated in the Keys.
Talking point #2
Action Alternative 1, which would test only non-chemical control methods, was identified as the environmentally superior alternative in the Draft EIR/EIS. However, this alternative is limited in the number of test sites within the Keys. The Sierra Club has proposed an Enhanced Alternative 1, which would test the non-chemical methods at more sites than Alternative 1. The Water Board should choose Enhanced Alternative 1, not the Proposed Project.
Background
During the scoping phase, only the Proposed Project (CMT) was proposed along with the no action alternative. The Draft EIR/EIS added two other action alternatives in response to comments during the scoping phase. Alternative 1 was to only test non-chemical methods and Alternative 2 was to dredge various lagoon sites and replace the substrate with sand, an extremely unrealistic and expensive alternative. Although the Draft EIR/EIS states several times that Alternative 1 is the environmentally superior alternative, the agencies plow ahead with the CMT as proposed and discharge herbicides into the Keys.
Talking point #3
The Antidegradation Analysis is essential information about the Water Board’s reasoning and justification for allowing water quality to be degraded by the discharge of herbicides in an ONRW. It should have been made available to the public during the comment period as stated it would be. The State Board’s own adopted procedures for compliance with antidegradation regulations require that the Antidegradation Analysis be included in the environmental review process. The public has been unlawfully precluded from reviewing the Antidegradation Analysis during their review of the Draft EIR/EIS.
Background
Lake Tahoe has been designated as a Tier III Outstanding National Resource Water (ONRW) and is therefore protected by federal antidegradation regulations. (Antidegradation, for the waters of Lake Tahoe, means that only temporary degradation from their existing very high quality is allowed - “weeks to months, not years.”) The regulations require an antidegradation analysis (AA) for the CMT. The agencies stated in August 2019, during scoping for the Draft EIR/EIS, that the AA would be included in the document. It was not. The agencies later stated that the AA would be published in August 2020, during the comment period on the Draft EIR/EIS, and then postponed publication again. Now the agencies are saying that the AA won’t be available until the Water Board issues the draft permit for the CMT in March 2021. This is unacceptable and unlawful.
Talking point #4
The one-time test of herbicides will not only be ineffective, but will open the door to perpetual herbicide use. Everywhere they have been used, perpetual treatment with herbicides has always been necessary. Perpetual herbicide treatment would violate the antidegradation regulations, which allow only temporary and short-term degradation in water quality (short-term being on the order of weeks to months).
Background
The Proposed Project would apply herbicides once. However, a single application of herbicides has never successfully controlled invasive aquatic weeds elsewhere (such as in the Midwest and Northeast, where communities have battled the growth of weeds for decades). The fact that the project proponents previously filed an application for a permit to apply herbicides in the Keys for up to 12 years shows that they do not believe that a single application would achieve successful control. The agencies, however, did not disclose this previous application in the Draft EIR/EIS because they knew that a one-time treatment would not work and more than one application would violate regulations. If the Keys are allowed to test with herbicides this one time, the door will be opened up for further herbicide use in the future.
Talking point #5
Herbicides do not solve the root cause of the weed problem, which is decades old continuous inputs of nutrients and other pollutants from the surrounding community. In fact, herbicides actually make it worse. Nutrients from the plants killed by herbicides are quickly released into the water, enhancing the conditions that promote harmful algal blooms, including deadly cyanobacteria (blue-green algae) blooms. Herbicides cannot solve the nutrient problem because the nutrients in the dead plants remain in the system to nourish weed growth during the next growing season.
Background
Invasive weed infestations in the Keys have become more severe every year during the last two decades, as could be predicted when construction of the Keys 60 years ago replaced a large portion of the Upper Truckee River marsh with an unnatural stagnant lagoon system. The lagoons are surrounded by houses with verdant green lawns which contribute nutrients to the lagoons. Nutrients are also contributed by South Lake Tahoe’s stormwater, which flows into Lake Tallac (adjacent to the lagoons) and then travels via groundwater into the lagoons. Nutrients from the lawns and stormwater have been accumulating in the lagoon water and bottom sediments for 60 years.
Talking point #6
Only installation of a physical barrier in the channel can prevent further spreading of the infestation around the Lake. Ultimately, only restoring the Tahoe Keys lagoons and channels to natural wetland will remove the conditions that invite the weeds to grow.
Background
For years invasive weed infestations in the Keys lagoons have been so severe that the top three feet of the weeds must be mowed and removed to ensure that boats can travel from backyard docks to the Lake. The enormous numbers of weed fragments created by mowing have seriously exacerbated the weed problem. Fragments take root in the lagoons, float into the Lake, and attach to boats which transport them into the Lake, spreading the infestation to many locations around the Lake. The 100-acre infestation in the Lake immediately outside the Keys West channel to the Lake is the largest. Only in recent years did anyone try to keep fragments out of the Lake. A fragment-trapping system installed in the entrance channel catches only an estimated 80% of the fragments; the bubble curtain fragment trapper was not operational in June and July of 2020, during the height of boating season. It is obvious that something more than testing and controlling the weeds is necessary to protect Lake Tahoe from the Keys and that protection in the short term is a barrier. It is also clear that a long-term solution is needed to protect Lake Tahoe. The Sierra Club believes that long-term solution should include restoring at least some of the severely stagnant ends of the finger-like lagoons.
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