The worst fears of flooding last week in Yosemite were unrealized (for now) and the park has reopened.
The Merced River (measured at the Happy Isles Bridge below Vernal Falls) crested at “only” 3000 cubic feet per second at 11 PM on Saturday night. The chart below shows the flow doubling over the course of the week, as well as the hourly fluctuations which show peak flows each day around midnight.
Peak flows of 3000 CFS or greater are not uncommon – flows reach that level in 30% of all years. The highest ever recorded was 9030 CFS in 1997 after the New Year’s deluge.
On June 20, 2017, the flow at Happy Isles reached 4270 CFS – a value that may yet be surpassed this year when the weather warms up.
Last week Sacramento station KCRA posted stunning aerial video of Wapama Falls. Beginning with a close-up of water tumbling over rocks beneath the pedestrian bridges, the video then all too quickly zooms out to show the falls in their entirety – giving a sense of Wapama’s magnitude. (The combination of Wapama’s flow and height are unmatched by any of Yosemite’s outstanding waterfalls.)
Wapama also reached a peak flow of 848 CFS for the week late last night. Unfortunately the footbridges are unsafe to cross at high levels – at least 4 deaths have occurred – SO DO NOT TRY TO CROSS THE BRIDGES WHEN THEY ARE MARKED CLOSED OR WHEN THEY ARE UNDER WATER. The National Park Service has been working on improving the bridges, which they hope to have completed by next year.
The present state of the bridges at Wapama (unsafe at high water) is one more example of how visitor access has been denied to the Hetch Hetchy area of Yosemite National Park. If you have not already done so, please sign our letter to the Superintendent to support improved access at Hetch Hetchy.
Our Spring 2023 newsletter has begun arriving in mailboxes! Read it online here.
If you’d like to sign up to receive a hard copy, please send your name and address to admin@hetchhetchy.org.
The newsletter includes updates and articles such as…
This year’s record-breaking winter promises an exciting waterfall season in Hetch Hetchy.
Groundwater recharge policies can and should be improved in California, a fact highlighted by a winter of flooding.
Yosemite’s Best Kept Secret – Hetch Hetchy receives only 1% of park visitors. For the sake of restoration, we have to change that.
Updates on our Keeping Promises campaign: how Restore Hetch Hetchy is working to increase access to the area.
Congressman McClintock reintroduces the Yosemite National Park Equal Access and Fairness Act: legislation that would increase SF’s “rent” and improve recreational opportunities in Hetch Hetchy.
Restore Hetch Hetchy remembers our longtime board member Rex Hime, and our lifelong supporters, Dorothy Jean Bobbitt and Marilyn Brown, who joined our Legacy Circle this past year.
Our Annual Dinner will be held in Berkeley on October 7th, with keynote speaker Kim Stanley Robinson.
Joining our team are Marissa Leonard, Engagement & Development Director, and Carlos Antunez, Community Outreach Liaison.
Available for order are a new set of notecards by artist Lesley Goran, who designed our letterhead.
Just a touch of history. Sadly, sometimes telling lies pays off.
The San Francisco Examiner, and its Publisher William Randolph Hearst, were among the most fervent supports of damming Hetch Hetchy Valley in the early 20th Century. In 1913, as the Raker Act was headed to a crucial vote before the United States Senate, the Examiner published a special Washington DC-only issue dedicated to swaying the vote.
Some of the facts printed by the Examiner in its zeal to pass the Raker Act were debatable. And the courts found that some of the facts were not only incorrect, they were libelous.
So far, so good. It’s the Examiner’s right to advocate. However, as Senator Daniel Patrick Moynihan and others have famously said, “Everyone is entitled to their own opinions, but not their own facts.”
The Examiner’s argument in favor of damming Hetch Hetchy did indeed go beyond stating facts. The newspaper smeared Taggart Aston, an engineer who had written to Congress opining that San Francisco could develop the Mokelumne River at lower cost (and without need to dam Yosemite’s Hetch Hetchy Valley). Describing Aston, the Examiner printed:
“Tool, sycophant or hireling of the said Eugene J. Sullivan, and, therefore, of “a thief” and “of a man who ought to be in the penitentiary” and that as such he would “stultify himself and prostitute his personal honor and professional reputation to do the servile bidding of such an employer without reference to truth and right” (Quotes from San Francisco Examiner)
As Restore Hetch Hetchy supporters know, the Raker Act the Raker bill passed the Senate on December 6, 1913, with 43 “yeas”, 25 “nays” and 28 abstentions. President Woodrow Wilson signed the bill into law on December 19, 1913. Might the vote might have been different, if Sullivan’s proposal to develop the Mokelumne River instead had been given serious consideration?
Publisher William Randolph Hearst was found guilty of libel for statement about engineer Taggart Aston.
In 1914, Taggart sued the Examiner and Hearst for defamation and won. The Examiner and Hearst appealed and lost.Taggart’s reputation was restored, but Hetch Hetchy Valley was clear cut and buried beneath 300 feet of water behind O’Shaughnessy Dam.
In 1923, Oakland, Berkeley and other East Bay cities created the East Bay Municipal Utility District and then built Pardee Dam on the Mokelumne River, delivering water to the Bay Area by 1929. EBMUD even provided emergency supplies to San Francisco in the early 1930’s before San Francisco had completed its pipelines from the Tuolumne. Since EBMUD started its project after San Francisco and finished earlier, perhaps Aston was right after all that the Mokelumne was a more practical project.
To meet demand, locally and around the world, California farmers have covered some 1,600,000 acres in almond trees (if all in one place, the orchard would be a square 50 with sides measuring 50 miles).
An almond croissant with a cappuccino can be an irresistible combination.
Many have criticized growing almonds in California for using too much water in a semi-arid state. After all, it take a gallon to grow a single nut.
It’s important to realize, however, that it simply takes a lot of water to grow food (albeit some foods more than others). Most of us consume far more water through the food we eat than we use in our homes. Agricultural water use in California is roughly 4 times as high as urban use.
In recent decades, California farmers have increasingly turned to almonds and other nuts. Trees do need to be watered every year, so many farmers will plant some acreage in row crops, such as tomatoes, which can be fallowed in dry years. That’s the life of the California farmer, at least many of them.
Noted Arizona State hydrologist Jay Famiglietti puts it mildly, possibly with a bit of sarcasm: “To knowingly go into a region like that and drill deeper wells really tests the limits of corporate ethics. This is coming at us at 100 miles an hour.”
It’s inexcusable.
There ought to be a law. Well, there is, but California’s Sustainable Groundwater Management Act does not require sustainability until 2040. That’s “the best the legislature could do” when it passed the law in 2014. Sadly, by the time 2040 rolls around, some of the damage will be irreversible.
As Bloomberg points out, the average depth of wells drilled by institutional investors is over 1000 feet. They are sucking the land dry.
Note also, the 110,000 acres planted by the investors in Bloomberg’s article use more water than all the customers in San Francisco’s regional water system.
It’s hard to imagine any elected official defending this abuse of California’s groundwater basins. Yet, collectively, it’s a problem our legislature has been unable to solve.
Hetch Hetchy is a similar example. No one would defend damming a national park today. Many politicians know restoration is the right thing, but are reluctant to take action. Restore Hetch Hetchy is looking for elected officials with the courage to do what we all know is right.
Imagine the largest freshwater lake west of the Mississippi River, between Fresno and Bakersfield but along the west side of the Central Valley. At 690 square miles, Tulare Lakewas 3 1/2 times the size of Lake Tahoe. Many believe the largest population of native people in what is now the United States lived along the Tulare lake, supported by its plants, fisheries and wildlife.
The Kings, Kaweah, Tule and Kern are the principal Tulare Basin rivers that drain the southern Sierra, historically flowing into terminal lakes. Principal central Sierra rivers such as the San Joaquin, Merced, Tuolumne and Stanislaus flow north toward the Delta, albeit after being mostly diverted for agriculture or direct human consumption. Currently flooded areas are shown in purple.
Beginning around 1870, Americans began to control the waters feeding Tulare lake and to irrigate the productive land, pushing native peoples out. Today, the former lake bed is mostly farms and ranches, but also includes some small towns.
In most years, the rivers feeding Tulare Lake are fully controlled upstream. For the first time in 26 years, however, heavy March rains reached Tulare Lake, breaking levees and flooding farms and homes. People are even more worried, however, about what will happen when the record southern Sierra snowpack melts. (The town of Corcoran, for example, with a population of 22,0000 is taking emergency action to raise its levees.)
Renowned journalist Lois Henry reports that the J.G. Boswell Company has broken levees to flood other farmers and protect is own land, raising additional questions and no small amount of suspicion in advance of the impending snowmelt. (Rising Tide: The Great Mississippi Flood of 1927 and How It Changed America, John M Barry, is a fascinating book which tells a story of breaking levees to divert floodwaters, helping to elect Huey Long as Governor then Senator, Herbert Hoover as President as well as reinvigorate Ku Klux Klan.)
There is concern further north as well. The “capacity” of the Tuolumne River through Modesto, is only about 11,000 cubic feet per second. There is still space in Don Pedro, Cherry and Hetch Hetchy Reservoirs, to absorb some of the spring snowmelt, but a sudden prolonged hot spell, or worse yet a substantial warm rain, could cause flooding along the Tuolumne. (Hetch Hetchy Reservoir does not need to leave space for flood control as that “space” was transferred to New Don Pedro in 1970.)
California is a semi-arid state (well, maybe not this year), always facing challenges to support its population, agricultural sector and natural environment. For most of us, 2023 is a welcome relief and it feels good to be wet again. But the winter’s storms have come at a cost which we will not fully understand until the snow melts.
Hard rain brings Yosemite’s waterfalls to life. Warm rain on snow can cause especially rapid runoff, and severe flooding. Yosemite Valley dodged a bullet last week when the increase in Merced River flow was relatively moderate.
Further south, residents in the Kern River canyon were not so lucky – more below.
Yosemite National Park remains closed, but photos Tueeulala (left) and Wapama Falls were captured through the mist. (unknown source)
Rain and melting low elevation snow feed numerous intermittent waterfalls on the north wall at Hetch Hetchy.
Rainfall amounts were similar March 9th and 10th throughout the southern Sierra, sharply increasing runoff everywhere. But slightly different temperatures at similar elevations in Yosemite Valley, at Hetch Hetchy, and on the Kern River led to very different results.
In Yosemite Valley, the average temperature was 35 degrees. The Merced River at Happy Isles (just down from Vernal Falls) increased fivefold from 140 cubic feet per second (CFS) on March 9 to 724 CFS on March 10.
At 39 degrees, Hetch Hetchy was a bit warmer. Falls Creek at Hetch Hetchy (Wapama Falls) increased tenfold, from 57 cubic feet per second on March 9 to 579 CFS on March 10.
Temperatures on the Kern River were higher – averaging 42 degrees. Flows at Kernville increased more than 34-fold, from 561 CFS on March 9 to an average of more than 19,185 CFS on March 10 (flows exceeded the rating table maximum of 41,400 CFS between 10 am and 6 pm). Homes were destroyed, but sensible residents got out of the river’s way. See video below.
Most of the time, flows on the Kern are smaller than those on the Merced. Many of us recall the devastating 1997 New Year’s Day flood in Yosemite Valley when flows reached 24,600 CFS. Had weather been a few degrees warmer last week, the flooding Yosemite Valley might have been more damaging than it was in 1997.
Let’s keep our fingers crossed that the large storm forecast for this week doesn’t flood Yosemite, the Kern River canyon or, for that matter, anywhere.
Our Spring 2023 newsletter has begun arriving in mailboxes! 
