MARLETTE LAKE, Nev. – Shovels have hit the dirt as part of the Marlette Lake Dam rehabilitation project’s groundbreaking ceremony held at the Spooner Lake State Park Visitor’s Center on Thursday, June 12. The project aims to ensure the longevity of the historically significant community resource.

“Without this project, our dam is at risk of catastrophic failure,” Chelsea Cluff, professional engineer and project manager with Lumos & Associates, explained at the event, “partially due to the age of the embankment.”

The dam is now over 150 years old.

A 2017 survey revealed the risk of catastrophic failure, particularly under seismic scenarios, and also found significant seepage that could compromise the dam. Additionally, the survey identified that the emergency spillway is undersized for certain flood conditions.

A failure would mean Marlette’s water would flow into Lake Tahoe and bring debris with it, raising clarity concerns. Marlette Lake is a component of the Marlette Lake Water System, which includes Marlette Lake and Hobart Reservoir, and is a major water resource for Carson City and the primary resource for Virginia City. A dam failure could spell the loss of a vital water source. While providing water to adjacent communities, the lake offers habitat and a location where the Nevada Department of Wildlife maintains a brood stock of rainbow and Lahontan cutthroat trout.

The water system was constructed during the Comstock era in 1873. What makes the system all the more special is the inverted siphon that brings water to Virginia City.

“I don’t know anything else like it in the world,” Brian Wacker said at the ceremony, professional engineer and Nevada State Public Works deputy administrator.

The site is listed as a National Historic Civil Engineering landmark and was added to the National Register of Historic places.

The rehabilitation project was initiated in 2018 and Wacker said they received their final permit just a few weeks ago. The relatively long pre-construction period points to the particularly special nature of the project. Wacker expressed the project needed just about every kind of permit, underscoring the scale of the project and its significance environmentally and historically.

Its location in the Tahoe Basin meant it required the Tahoe Regional Planning Agency’s sign-off as well. Additionally, as a recipient of a $10 million FEMA grant, it required additional layers of oversight.

The total funding for the project amounts to $23.5 million, which includes Nevada State Legislature approved $13.4 million.

Crews have only recently accessed Marlette now that snow has melted. They’ve placed aqua dams to hold water back and allow crews to dewater the area near the dam for excavation.

The lake has undergone a draw down of about 20 feet, leaving about 22 feet of water. It is estimated refill will take 6-7 years based on historical weather patterns.

Following excavation, crews will replace old decaying riveted steel pipes in addition to installing other components. Crews will then rebuild the dam embankment. The finished project will extend and stabilize the dam by three feet.

Although the work will excavate most of the original dam, a portion of both the 1873 dam and the 1959 expansion dam will remain due to time constraints and be incorporated into the rehabilitated design.

Cluff explained the goal this summer is to complete the embankment. Ancillary work is scheduled for next summer, which includes a control building on top of the dam.

Project engineers expect completion in October 2026.

The project comes with its fair share of recreational closures. The Marlette Lake Trail, Hobart Road, portions of the Flume trail and the lake itself are closed, in addition to other impacts. For a full map of closures, visit publicworks.nv.gov.

Questions can be sent to marlettelakedam@gmail.com or you can call the hotline at 775-391-4119.