Destroying Lake Pillsbury is an expensive gamble with water supply

The current narrative that dam removal in Lake County is the only viable solution is being pushed forward without proper scrutiny. No real weight is being given to the true potential financial costs and the very real threat to our regional water security. This narrative effectively ignores that the Eel River water diverted from Lake Pillsbury ultimately flows into the Russian River, where it is then routed into pipelines supplying it throughout Sonoma County and Marin County, into the taps of cities like Sonoma, Petaluma, and Novato.

The North Marin Water District has stated the “Russian River, which provides approximately 70% of Novato's water, originates in Mendocino County and derives supply from both the Eel River and the Russian River watershed.” Without understanding the history behind this, it is likely that many do not know what a gamble special interests are attempting to make with the water needs of 600,000 people as they urge the Federal Energy Regulatory Commission (FERC) to order the destruction of Lake Pillsbury.

In 1922, following the completion of Scott Dam, the Gravelly Valley of Lake County was filled to form what became known as Lake Pillsbury. The Lake County community of Hullville was then submerged under 125 feet of impounded Eel River water. At that time, it was investors from San Francisco who set this transformation into motion, already seeing the need for hydroelectric production to power Ukiah and the diversion of water into Sonoma County. The system of dams and diversion became known as the Potter Valley Project.

During the next 100 years in Lake County, the community of Lake Pillsbury would ultimately develop along the shores of the destroyed town of Hullville. During this same time, development boomed throughout Sonoma and Marin counties fueled by the Eel River bolstered water supply of the Russian River. In 1977, regional representatives presented testimony to Congress on the need for further strengthening of the water supply by constructing the Warm Springs Dam to create Lake Sonoma. Lake Pillsbury, Lake Mendocino, and Lake Sonoma have all come to form the backbone of the Russian River's ability to meet an ever growing demand.

In those Congressional hearings, a Mendocino County Supervisor stated: “By far the major portion of current summer demand for domestic and agricultural use of water in Southern Mendocino County, Sonoma County and Northern Marin County is met by water released from Lake Mendocino down the Russian River. But, prior to 1908 very little water flowed in the Russian River during the summer months and in dry years the river was usually dry.”

This stands in stark contrast to what many in the region have come to take for granted, that the Russian River has become not just a source of water but also a vacation destination. “As a result of the Van Arsdale diversion and creation of Lake Pillsbury, water flowed in the Russian River all summer, and agriculture developed along the Russian River in Potter Valley, Southern Mendocino County, and Sonoma County. Recreational uses of the Russian also flourished.”

The prospect of the Russian River going dry as it runs along the Mendocino-Lake County line into Sonoma County is frightening, especially in the age of megafires that our region is experiencing. The Eel River in Lake County may go dry and without the water in Lake Pillsbury and Lake Mendocino the regional wildfire danger would seem only to be further heightened.

There have been many assumptions made by dam removal proponents, including that the regional water supply would not be threatened; that the cost to remove the dams is cheaper than providing fish passage; and that the environmental impact on Lake County is minimal. These assumptions simply do not hold up when the broader context is considered.

The most optimistic of projections regarding water supply have been previously used as justification to remove Scott Dam and destroy the water storage provided by Lake Pillsbury. Lake Mendocino has dropped to and remains at historic lows in the midst of this drought. The worst-case scenarios of Lake Mendocino drying up nearly came to pass just in the last year as the water level continued to drop precipitously.

There are many cost-effective methods for fish passage in Lake County that were eliminated from further consideration because they were not viewed as the most desired outcome. Some of these, such as a trap & haul option, or pressurized transport systems, could be implemented quickly without the need for the significant physical infrastructure associated with a fish ladder, even if only on a short-term basis.

Apparently, these options did not fit the narrative that the only viable fish passage option is to remove Scott Dam. In fact, their success would have weakened the argument to destroy Lake Pillsbury and risk our region's water security. These alternatives were not weighed against the real potential cost of dam removal or realistic threat to regional water supply. Once the dams are removed there is no going back, and it would not be possible to attempt these otherwise cost-effective alternatives.

Even the early, preliminary, cost estimates presented by the Two Basin Solution provided a massive range. The dam removal itself was estimated between $30 and $120 million. What received even less focus were the estimates for Sediment Removal and Vegetation Management. These were each estimated to cost between $25 -$100 million. That put the conservative estimated cost at approximately $80 million, but the more realistic costs at $320 million. When all costs were considered the range came to $400 — $520 million. Lake County did not have a voice in these discussions, so already decisions such as removing the sediment left behind have been noted as infeasible, due to cost. These rough costs could continue to rise as operations are more fully developed.

Dam removal proponents argue that Scott Dam is unsafe. What they carefully omit is that the majority of dams in California, especially those of any substantive size, are considered high risk. In fact, over 90% of the acre feet of dam water storage is classified as high risk just like Scott Dam. This cannot be the basis to begin eliminating water storage across the state.

Forcing dam removal to begin before anyone has the chance to understand the real risks and costs involved seems to be the current strategy. That is why it was necessary to exclude Lake County from the process. Once the dam is out and Lake Pillsbury destroyed, the costs of the resulting environmental harms in Lake County and securing new water sources in Mendocino, Sonoma, and Marin will be forced upon all of us.

For over a century, regional decisions surrounding development have been made in reliance on the water in Lake Pillsbury. The danger of this was foreshadowed in 1977 Congressional testimony:

“The pressure on demand is even greater in Sonoma and Northern Marin Counties because they are closer to the metropolitan San Francisco Bay Area.

For periods of time this pressure may be contained. But we will soon have more wet years. There will be more homes built, businesses started and acres planted in the Russian River Service Area. Every member of this Committee knows this trend cannot be stopped `once and for all.'

Some of the later words still ring true to this day: “When the next dry cycle comes — when demand is much higher — the economic loss that will be suffered, if our water supply is not increased, will be shattering to lives and our economy.” These are the words that helped convince Congress to increase the water supply by building a new dam, and they should certainly give proponents of destroying regional water storage at Lake Pillsbury pause as we enter increasingly dramatic drought.

Residents of Marin, Sonoma, and Mendocino counties are encouraged to contact members of their local City Councils, Board of Supervisors, and other governing bodies to request open discussion of these concerns. You can also submit your comments to the Federal Energy Regulatory Commission directly at https:// ferconline.ferc.gov/QuickComment.aspx (P-77)