Alder Lake on the rise again after historically low water levels

Anyone who lives near or has driven by Alder Lake in recent weeks has probably noticed its unusually and unseasonably low levels, with more mud and stumps than water showing.

At its eastern end near Elbe, only a narrow rivulet of the Nisqually River remains visible while close to popular Sunny Beach Point, an old railroad trestle bridge and foundations from the submerged town of Alder can be seen.

This is not just your eyes or memory playing tricks on you. Tacoma Power, which operates the Alder and LaGrande Dams that control the lake’s level, has confirmed that the water levels seen in recent weeks are historically unprecedented.

“We’ve never been to this elevation before; not that anyone can remember,” stated Stan Strand, project manager for the two dams.

He noted that nowhere among records dating back to the early 1960s have such low levels been recorded.

The cause of it was an unusually hot, dry summer, followed by a cool and dry September.

“We typically start the summer full,” explained Tacoma Power’s resident fish biologist Florian Leischner. “This is due to spring snowmelt. It’s normal for the levels to drop over the course of the summer, but typically this is then offset by heavy rains in the fall,. This year the rains just haven’t come.”

Prior to construction of the two dams in the first half of the 20th  century – the LaGrande Dam around 1910 and the Alder Dam in 1945 – the Nisqually River would rise and fall naturally with the weather and the seasons. This is no longer wholly the case, as water levels are now adjusted via the dams based on a variety of regulatory and power generation requirements.

The main federal organization regulating the dam is the Federal Energy Regulatory Commission. As described on its website, “FERC is an independent agency that regulates the interstate transmission of electricity, natural gas and oil.” It also “licenses and inspects private, municipal and state hydroelectric projects.”

According to Leischner, the Alder and LaGrande dams operate under a 50 year FERC license which was last renewed in 1997. He explained how as part of the licensing and ongoing audit and inspection process, numerous stakeholders are involved and a multitude requirements must be met. In the case of these dams, those stakeholders include U.S. Department of Fish and Wildlife, the National Oceanic and Atmospheric Administration, and the Nisqually tribe.

Operators of the two dams have a delicate balancing act in trying to maintain 114 megawatts of annual power output (which provide renewable, “green” electricity to roughly 16,000 northwest homes, including those in Eatonville and the Ohop Valley) while also ensuring adequate flows for downstream salmon habitat in accordance with treaty rights and federal licensing requirements. Lake levels rise and fall accordingly.

Leischner described how 2018 has been “the third time in four years that we’ve had to reduce minimum flows.” Water flows have been so low, in fact, that Tacoma Power has had to apply for two separate variances from FERC this year for being unable to meet license requirements.

The lake’s historically low levels have impacted many in the area who enjoy boating on its 3,065 acres or recreating along its 28 miles of shoreline. Fisherman who prize its native cutthroat and rainbow trout or its introduced bass, crappie, yellow perch and kokanee have found themselves mired in knee deep mud, their lures snagged on exposed stumps and boats nearly impossible to launch as the ramp peters out scores of feet from the water’s edge.

“People like to point the finger at Tacoma Power (for too much or too little water flow),” Leischner lamented, “but we’re really at the mercy of mother nature.”

Thankfully, recent rains have begun to refill the reservoir, much to the relief of Strand and his 15 on-site employees. Together they carefully monitor numerous screens and instruments in the control center at LaGrande as well as watching for the dreaded “vortex” that could form above the Alder Dam if levels ever approached a critical low. At that point, the power generating turbines would have to be shut down to avoid air entering them, causing cavitation and damage to the equipment.

“Let’s hope it never comes to that,” Strand said.

With any luck, the lake will soon be back to normal levels.. When asked what role climate change may play in low water flows of recent years, those interviewed were unwilling to speculate, although they did acknowledge that strategic planning is underway at levels “above our pay grade” in the case the weather patterns of late become the new normal.

In the meantime, Tacoma Power carries on with its stated mission “to provide high-value, competitively priced products and services to our customers through the quality of our employees, and the responsiveness that results from local ownership.” 

And as for those who live along Alder Lake’s shores or in the fir-clad hills and valleys that surround it, they watch, and they wait, and they wonder.