Diving Deep to Protect Lake Tahoe: Inside Clean Up the Lake’s Cold-Water Mission

By Charlie Pankey | Sierra Rec Magazine

Lake Tahoe is often described as impossibly clear, impossibly blue, and impossibly pristine. But beneath the surface — far beyond what swimmers, paddlers, and boaters ever see — another story is unfolding.

In the latest episode of the Sierra Rec Now Podcast, I sat down with Jenny Uvira, Programs Manager at Clean Up the Lake, to talk about one of the most ambitious lake stewardship projects ever attempted in the Sierra Nevada: a full 72-mile deep-water circumnavigation of Lake Tahoe, targeting depths of 35–55 feet.

This isn’t shoreline cleanup. This is cold, dark, technical diving — and what the team is finding below the surface may surprise even the most devoted Tahoe locals.

What Lies Beneath Lake Tahoe’s Surface

Clean Up the Lake first made headlines several years ago after completing a 72-mile cleanup around Lake Tahoe at shallow depths (0–25 feet). That effort removed over one ton of submerged debris, from sunglasses and bottles to large industrial waste.

But recent pilot projects revealed something unexpected.

“At deeper depths — 35 to 55 feet — we’re actually finding more trash than we did closer to shore.”
— Jenny Uvira, Clean Up the Lake

According to Jenny, underwater currents, lakebed contours, and decades of unnoticed accumulation have turned deeper zones into collection points for debris — areas rarely accessed by recreational divers or cleanup crews.

A Colder, Harder, More Technical Mission

Diving Lake Tahoe in winter is not for the faint of heart. Water temperatures at depth can drop into the mid-30s, with active currents that prevent freezing but increase cold exposure.

To safely operate in these conditions, Clean Up the Lake uses advanced tools including:

Diver Propulsion Vehicles (DPVs) — underwater scooters that allow divers to cover large areas efficiently
Nitrox (enriched air) — enabling longer bottom time with safer surface intervals
Dry suits and layered thermal systems designed for alpine cold-water environments

“We’re extremely conservative with dive planning,” Jenny explained.
“Safety always comes before speed — even if it means the project takes longer.”

The Most Toxic Trash Found Underwater

Not all debris poses the same threat. When asked what worries her most, Jenny’s answer was immediate.

“Tires. Always tires.”

Submerged tires slowly break down, releasing toxic chemicals into the water column. During past projects, Clean Up the Lake has removed dozens at a time, including more than 70 tires from Convict Lake alone.

Batteries, construction debris, and industrial materials also rank high — often unintentionally lost during storms, dock work, or shoreline construction.

“I truly believe most of this isn’t intentional,” Jenny said.
“But that makes awareness even more important.”

Sample Q&A: From the Podcast

To give readers a taste of the conversation, here’s a short excerpt adapted from the Sierra Rec Now interview.

Q: Why does deeper water hold more trash than the shoreline?

Jenny Uvira:
“At shallower depths, people can still see debris — swimmers or paddlers might grab it. But once you get deeper, fewer eyes are down there. Add underwater currents and lakebed shelves, and debris naturally settles into those deeper zones.”

Q: Are historical artifacts ever found during dives?

Jenny:
“Yes — and when we do find something that appears historic, we don’t remove it. Our divers mark the location, and we work with archaeologists and local agencies to preserve history responsibly.”

Q: Do volunteers need scuba certification to help?

Jenny:
“Not at all. We need kayakers, surface support, boat captains, and litter sorters. Once debris comes out of the lake, it’s sorted into 83 different categories so we can track pollution trends and work with communities on prevention.”