Extreme Weather and Power Outages

By Theresa Phillips

In December, LMUD line crews worked day and night on widespread power outages during snowstorms. Photos by LMUD Foreman Adam Hull

Snowfall in Lassen County over the past few years has been well under the annual average of 44 inches. But the final two weeks of 2021 delivered nearly a year’s worth at once.

From December 14 to December 31, 2021, Lassen County received near-record amounts of snow. In Susanville, snowfall was recorded at more than 3 feet—equal to a year’s worth of snow in a two-week period.

Newer Lassen County residents may have been surprised by the amount of snow we received. However, old-timers will tell you this is far from the most snow they have seen.

December’s snowfall was heavy and wet. Often referred to as “Sierra Cement,” it wreaked havoc on trees and power lines. Lassen Municipal Utility District’s transmission lines from Susanville to Westwood were hit hard.

At about 5 a.m. December 14, the snow caused trees and branches to fall on LMUD’s lines, resulting in a systemwide outage. With heavy snow falling, crews were unable to access the remote area until daylight.

Where the lines were damaged, nearly 5 feet of snow had fallen, making it impossible to patrol by bucket truck. Crews used a Sno- Cat to patrol the lines and hiked through chest-deep snow to find the problem.

Around 10 a.m., crews found a tree on the line and removed it. Power was restored around 12:45 p.m.

But that was not the end of the outages. The next morning, LMUD customers again awoke to no power. Due to the extreme conditions, crews were forced to wait until dawn to patrol the 60 miles of transmission lines from Westwood to Susanville.

Many outages were caused by what is often referred to as “Sierra Cement,” heavy and wet snowfall. This wreaked havoc on trees and power lines in town and remote transmission lines that could only be accessed via Sno-Cat due to the chest-deep snow.

More trees and limbs had fallen. Crews cleared the lines and power was restored around 1 p.m., but almost as soon as it was restored, it was out again.

The decision was made to bypass our transmission lines and instead isolate LMUD’s system, serving customers through a connection to Honey Lake Power. Service was restored to most customers by 4 p.m. December 15.

In addition to trees and limbs on transmission lines, LMUD received nearly 200 calls from customers reporting lines down throughout the service territory. Crews worked around the clock to ensure the safety of customers and the community, prioritizing based on public safety and the number of customers affected.

One by one, all customers had power restored.

After patrolling both of LMUD’s transmission lines and working with PG&E staff, LMUD reconnected to the Caribou transmission line.

Receiving power from Caribou is part of LMUD’s standard operating procedure. That line allows LMUD to receive its contractually purchased power from the Western Area Power Administration and benefit from the stability of the grid.

It also is essential to Honey Lake Power fulfilling its power purchase agreement. HLP is under contract to sell power it generates to San Diego Gas and Electric.

Although PG&E has made improvements to the Caribou line, LMUD believes interconnecting with NV Energy—being able to receive power from the east—is in the best interest of customers and the district.

The Skedaddle Substation is expected to come online by the end of 2024. This will allow LMUD to have a redundant power feed for its system by incorporating the connection to the Caribou line into its operations as needed.

LMUD’s vision is to connect and support the community by providing safe, reliable, and sustainable service. LMUD will do its best to keep Mother Nature and Old Man Winter in their place.