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Drinking Water

Did you know all of the District’s drinking water comes from groundwater?

The District provides drinking water to over 14,000 homes. Water is pumped from 11 wells around the South Lake Tahoe area, disinfected and then immediately delivered to houses and stored in water tanks. Our groundwater originates right here in the Lake Tahoe watershed where we live. Snow falls in winter, melts in spring, and travels through a vast network of groundwater aquifers to Lake Tahoe. By pumping water from these aquifers, the South Lake Tahoe area has some of the tastiest and purest water in California.

Aerial view of Heavenly Tank 1, in a pine forest with lake tahoe and mountains in the background.


Drought Response

In response to drought and groundwater resource concerns, the state of California passed legislation that established a new structure for managing groundwater. The Sustainable Groundwater Management Act (SGMA) requires locally formed Groundwater Sustainability Agencies (GSAs) to be responsible for developing and implementing a Groundwater Sustainability Plan or an approved Alternative for the long-term management of groundwater in high- and medium-priority groundwater basins. The South Tahoe Public Utility District (District) is the GSA for the portion of our local groundwater basin (referred to as the Tahoe South Subbasin) within the District’s service area and the El Dorado Water Agency (Water Agency) is the GSA for the portion of the Tahoe South Subbasin outside the District’s service area. Under a Memorandum of Understanding, the District and the Water Agency work together to manage groundwater within our local groundwater basin.

By stepping up to serve as the GSA for the Tahoe South Subbasin, the District and the Water Agency have the primary say, and responsibility for, managing South Tahoe groundwater, instead of the State.

Groundwater Management Plan

Upper Truckee Marsh with fallen logs, grasses, moving clouds, and snow-capped mountains at dusk.

The District has a long history of working to protect our groundwater. In 2000, the District enacted its first groundwater ordinance and a Groundwater Management Plan (Plan) was adopted which focused on the impact of man-made groundwater contaminants on District wells. At that time, groundwater quality was being degraded by spills and releases of gasoline containing Methyl tert-butyl ether (MtBE) and dry cleaning solvents containing Tetrachloroethylene (PCE). The District developed a Plan to address these contaminants while continuing to provide high quality drinking water to the South Lake Tahoe area.

The District updated the Groundwater Management Plan in 2014 prior to the effective date of SGMA. Then in 2017, pursuant to SGMA, the District submitted Alternative Plans to the California Department of Water Resources (DWR) to continue management of  the Tahoe South Subbasin. DWR approved one of the Alternative Plans and authorized the District and the Water Agency to continue to manage the Tahoe South Subbasin (effective 2019). GSAs with approved Alternative Plans are required to submit annual reports and resubmit the Alternative Plan to DWR for approval every five years.

The District and El Dorado Water Agency are in the process of updating the 2014 Groundwater Management Plan for resubmittal to DWR by January 1, 2022.   Check out the groundwater management plan page to the right to learn more about how you can participate in the update process, read through Plan Documents, and receive Public Notices related to the update process.

Groundwater Well Survey

In the summer of 2017 the District started a survey of private well owners to better understand groundwater usage and concerns in the Tahoe South Subbasin.  The District received responses from 375 private well owners.  This summer (2020), the District is working to complete the survey by reaching out to the remaining 300 private well owners that were not contacted or did not respond in 2017. View our Groundwater Management plan page (to the right) to learn more about the survey.

Groundwater Contamination at South Tahoe “Y” Area

In 1989, the contaminant tetrachloroethylene (PCE) was first found in drinking water wells near the intersection of Highways 50 and 89, referred to locally as the South “Y” area. Today, the PCE remains in groundwater and forms a contaminant plume believed to cover an area of more than 400 acres. PCE is a manmade chemical that was used from the early 1960s through the mid-1980s as a solvent for dry cleaning clothes and degreasing metal. During the late 1980s, concerns about the toxicity of PCE led Federal and State environmental agencies to list PCE as a probable carcinogen and as a toxic pollutant. Presently, five public drinking water wells in the South “y” area have been impaired by the PCE Plume. None of the District’s wells are currently affected. When PCE is detected in a well, the well is shut down and treatment is added to remove the contaminant, or an alternative source of drinking water supply is provided. Water suppliers and regulatory agencies in the South Lake Tahoe area are working together to protect and sustain our groundwater resource ensuring that safe drinking water is provided to all of our customers.

A map showing PCE groundwater contamination in South Lake Tahoe, CA, with affected wells and flow direction.
Public Webinar Draft IRAP - 03/31/2020 
Public Meeting - 06/26/2019 Groundwater Contamination at South Tahoe "Y" 
Public Meeting - 03/06/2019 Groundwater Contamination at South Tahoe "Y" 
Public Meeting - 08/08/2018 Groundwater Contamination at South Tahoe "Y" 
Public Meeting - 02/07/2018 Groundwater Contamination at South Tahoe"Y" 
Public Meeting - 11/07/2018 Groundwater Contamination at South Tahoe"Y"