RETIREMENT TRIP #7

Shasta: the Dam, the Lake and the Mountain

                                          Shasta Dam is the largest center-flow dam in the world.  The lake formed by the dam is the largest lake in California, and the mountain behind it is one of the tallest in the nation.   The water of Shasta Lake sparkled this morning under a blue sky with only a few cirrus streaks overhead.

Only trickles of water left Shasta Dam, but we could hear
the turbines generating electricity as water poured
through the five exit pipes.

By 1:00 p.m., a few raindrops dotted the car, but in the interim we walked the entire span of Shasta Dam and back—3,460 feet one way plus side views from the parking lots and the visitor center museum.  At 10:30 a.m., we realized free tours could be available and arranged.

“Are you sure this is what you want?” asked Hal at the front desk.   He seemed really gruff.   “We have lots of rules and it takes an hour.”

As we walk from the Visitor Center, the Sacramento River
stretches in a blue ribbon from the base of Shasta Dam.

He gave us tickets and a briefing on security.  “No bags, packages, pocketbooks, backpacks, electronic devices, Fit Bits, food, beverages allowed.  Be at the second station before 11 a.m.  It’s a 15-minute walk out there.  Be on time.” 

I didn’t tell Hal we had already walked well past the second station and back.

Turns out Hal was our tour guide for an hour-and-ten-minute-long walking tour of Shasta Dam.  He took us down 25 stories of the 42 stories to the base of the dam--602 feet from top to bottom, as tall as a 60-story sky scraper.  There he explained the process used to construct the concrete gravity dam, the second largest concrete dam in the United States.  Only Grand Coulee is larger.

Hal shows Andy the size of the release
holes part way down the spillway.

“Where we are standing, there is about 500 feet of concrete separating us from Shasta Lake,” he said.  The dam is 883 feet thick at the base and took 6.5 million cubic yards of concrete, weighing 15 million tons, to build.

Hal explained how workers poured 15 boxes at a time and each box took 58 buckets of cement before the form was removed.  Tubes kept the concrete from hardening too fast.  Moisture flows between the blocks, so the dam will not be completely cured until 2045, when it will be 100 years old.

Average pay for the construction workers from 1938 to 1945 was $.40 an hour, but the men filling the concrete boxes got $.90 an hour or $7.20 a day.  That was really good money for the early 1940’s.

Inside the dam, five turbines generate
electricity for northern California.

In 1942, many of the workers wanted to join the war effort after the bombing of Pearl Harbor.   President Franklin D. Roosevelt decreed the workers would get military status and come under the GI bill so that they wouldn’t abandon such a critical project.

Started in 1938, the Shasta Dam was completed ahead of schedule in 1945.  Today it backs up water for more than 35 miles to form Shasta Lake, California’s largest reservoir.

Shasta Lake actually extends for 35 miles north of the dam.

Hal told us that the greatest benefit is for Central Valley agriculture irrigation, even though the dam was initially for flood control.

“Now it is the key storage facility in one of the world’s most elaborate and extensive water development projects—the Central Valley Project, one of the leading agricultural producers in the world,” said Hal.

Today Shasta Lake is a clean, dependable water supply for irrigation, municipal and industrial use.  The wildlife habitat maintenance and power generation as well benefit millions of people miles away from the shores of this recreational paradise.

Far in the distance, Mount Shasta, hidden in clouds,
rises majestically with snow-capped peak.

Hal told us that initial plans to raise the dam 18.5 feet had been proposed.  He didn’t foresee it happening in the current political climate, but he thought given four more years, the proposal might well come to fruition.  That would raise the depth of the water in Shasta Lake from its current maximum of 517 feet and make more water storage possible.

We drove farther north in the early afternoon to check out the extent of the lake.  It was lower and its bathtub ring more evident the farther north we went, but the rainy season is coming.

Farther north in the recreation areas, the water level is lower,
but rainy season is coming soon by the looks of the clouds.

Hal had told us that some years ago the water level at the dam went up 33 feet in one day when lots of rain came down upriver.  The average rainfall in the watershed is 62-72 inches a year, with 90% of Shasta Lake water from rain and only 10% from snow.   It surprised us when he said that temperatures here could reach 112 to 120 degrees.

The greatest improvement in the dam since its completion in 1945 was the Temperature Control Device (TCD), put into operation in 1997.  Never before attempted, this device helped to protect the eggs of the Chinook salmon.  Two years in the making, it required 20,000 hours of deep-water saturation dives to assemble the 9,000 tons of steel and affix it to the face of the dam. The cost exceeded 80 million dollars.  This was the long-term fix designed by engineers and biologists to create a multi-level intake device to direct cold water releases through the power plant to meet project water and power demands without adversely affecting environmental needs.

Like so may who use Shasta for
recreational purposes, Andy and Sue
stop for lunch on the deck.

What TCD allowed operators to do was increase or decrease water flow from different levels of the lake through spillway valves at different elevations where the lake water was colder.  Biologists had discovered that the survival rate of the eggs of Chinook salmon greatly increased if the water temperature was below 56 degrees Fahrenheit.  The cold water released from lower levels of the dam help achieve the temperature needs of the eggs.

Certainly a deterrent, the rattlesnake
sign warns visitors not to venture
into restricted areas by the dam.

This all came about because over a period of years Chinook salmon and steelhead in the Sacramento River had suffered decline due to logging, mining operations and warm water temperatures in the Sacramento.  As Reclamation and other agencies studied the situation, they learned that the mortality rate could be improved by providing colder water releases from Shasta dam.  Hence, TCD.

Back in Redding, we check out the
superstructure under the Sundial Bridge
for a different perspective.

Thanks to Hal, our tour had been amazing.

We headed back to Redding for more walking and some different views of the Sundial.

In the northwestern part of town the McConnell Foundation has set aside a huge park with four small lakes for walking, the Lema Ranch Trails.


From Leah's Loop, one of the Lema Ranch Trails,
the mountains in the distance line the horizon.

We chose Leah’s Loop, a 1.75-mile trail on an asphalt path around the lakes and the private Lema Ranch house.  The scenery was beautiful, and there was even a dam and spillway inside the private area.  It was a gorgeous piece of property and a great way to build up an appetite for dinner.