Who We Are:
The Tahoe Water Suppliers Association (TWSA) membership is composed of the 11 principal Tahoe Basin municipal drinking water providers with lake intakes, representing a majority of the water consumers in the region. Source water protection is a large part of our mission of providing superior quality drinking water to our customers.
Why are invasive aquatic weeds and proposed weed management options a concern for the TWSA water providers?
In the past 8 years, the TWSA has established a source water protection education program which includes the popular “Drink Tahoe Tap” campaign. The outreach program focuses on educating the public about source water protection and promoting consumer appreciation of the excellent tap water provided to our communities.
TWSA members are concerned about the potential decline of consumer confidence in Tahoe’s outstanding tap water if a maintenance program is initiated using herbicides in the Tahoe Keys waters, which link to Lake Tahoe through two access channels.
In addition, Tahoe’s municipal water treatment systems are not specifically designed to remove chemical contaminants. Six TWSA members hold filtration exemption status from the USEPA, which is a rare status, usually granted only to a non-contact watershed. The treatment processes of ultra-violet and ozone disinfection used by the filtration exempt members are designed for deactivation of potential biological contaminants, not chemicals specifically. Other TWSA members utilize filtration, with treatment methods once again designed for deactivation of potential biological contaminants, not chemicals.
TWSA first became involved in Aquatic Invasive Species (AIS) issues in 2007 as the Lake Tahoe Watercraft Inspection Program was first being established. Our work focused then, and continues to date, on public education of the threat posed to water quality and water supply by the potential introduction of zebra or quagga mussels into Lake Tahoe by watercraft transport form an infected waterbody.
From 2009 to date, TWSA has maintained a presence in the working groups testing non-chemical methods such as rubber bottom barriers and diver assisted suction on the lake bed, to kill off the invasive Asian Clam. TWSA has provided staff support, water quality testing and financial support for the purchase of bottom barriers to the working group.
TWSA had been involved in the dialogue, and served as a working group partner with the Nearshore Aquatic Invasive Weeds Working Group (NAIIWG) since 2011, and most recently, the Tahoe Keys Property Owners Association Integrated Weeds Management Plan (TKPOA IWMP) technical advisory group.
Public Comment period is now open for the TAHOE KEYS CONTROL METHODS TEST – TENTATIVE RESOLUTION, TENTATIVE PERMIT, DRAFT DOCUMENTS AVAILABLE SEPTEMBER 15, 2021 FOR PUBLIC COMMENT. PUBIC COMMENTS DUE BY NOVEMBER 1, 2021.
TWSA Staff Summary on the project (click link to PDF)
See links below:
- Lake Tahoe AIS Challenge published August 2015
- Emerald Bay - Successful Weed Control using bottom barriers and diver assisted suction article
- PowerPoint of Emerald Bay Program (Dan Shaw)
- High Country News 9/28/15 - Can herbicides keep Tahoe blue?
A new chemical weed management plan has the lake’s water suppliers nervous.
- Lake Tahoe News article: Feds OK exemptions for herbicide use near Lake Tahoe; Tahoe Keys could benefit