Lake Merritt got its name from the big man who had it made, Samuel Merritt. It was he who dammed the mouth of San Antonio Slough by the 12th Street bridge, trapping the high-tide flow behind its water gate. Although some at first called the new body of water Lake Peralta, the people at large quickly recognized its creator with the name Lake Merritt. His big idea, which gave us one of Oakland’s crown jewels, had two purposes, one a great success and the other a long-forgotten failure. Why do such a thing?
Samuel B. Merritt (1822-1890) was born on a farm in Maine, earned a degree and practiced medicine in Massachusetts. When he got wind of the discovery of gold in California, he bought a ship, loaded it with lumber and other building supplies and served as navigator on a five-month voyage around the Horn. Arriving in San Francisco in 1850 the day after a major fire, he quickly sold his entire cargo at a profit. Then he began shipping lumber down from Eureka and buying property. He was shrewd and had, according to an 1892 profile, “an extraordinary faculty of making friends in those free and easy times.”
Though he soon left medicine for the shipping and building business, he was always known as Doctor Merritt. He joined the Oakland land rush early and was responsible for turning his property west of the lake into a desirable neighborhood of elegant houses. The City Council appointed him mayor in November 1867, when health reasons led Mayor William Crane to resign, and he won election the next spring.
Merritt served one term, until March 1869, and as with the Gold Rush his timing was lucky. As mayor, he negotiated a crucial agreement in April 1868 to give the city some access to its waterfront, wresting rare concessions from Oakland’s founding scoundrel Horace Carpentier and the railroad, co-owners of the waterfront. In one concession, the slough, which the railroad continued to own until the 1890s, was preserved from development.
In the old days the slough looked like the Alameda shore: mud and marsh.
Even before Merritt became mayor, his ideas for the slough were well known. The San Francisco Examiner reported in October 1867, “This bay it is proposed by Dr. Merritt to transform into a beautiful lake, by the construction of a dam at the Oakland Bridge.” I have no doubt this vision was what led the City Council to empower him.
What was he thinking? I feel sure he had a comprehensive scheme in mind, and 1860s medical knowledge favored his plan. It had two goals: cover up the mudflat and supply water for a sewer system.
The first part of the scheme was simple land improvement. Mudflats and marshes were considered unhealthful nuisances in the days before the role of germs and mosquitoes in spreading diseases was recognized. “Marsh air” and miasmas were the culprit of choice at the time. No one wanted to live near wetlands unless they were tidy lakes or clean streams. It didn’t help, either, that sewage was usually sent untreated into the nearest body of water.
The dam stretched from Fallon and 12th Streets to 1st Avenue and E. 12th Street, the narrowest part of the slough where embankments of ice-age sediment came closest to each other. The Examiner reported, “A hand-power pile-driver will be used, owing to the difficulty in passing any other under or through the bridge. The dam will be made water-tight, by driving planks into the mud bottom with battened joints, the whole secured to a framework. The flood-gates will be valves, which will be opened by flood tides and closed by the ebb.”
The 1869 Sessions map shows the Lake Merritt dam and Dr. Merritt’s nearby property. The other bridge across the lake is a phantom project, proposed but never built. We can’t always trust old maps.
Between the winter king tides and a wet rainy season, the lake filled up nicely. In January 1869 the Chronicle wrote, “The lake will become a favorite resort for holiday visitors from this side [of] the bay, because of its picturesque appearance and the splendid opportunity it affords for boating.”
In March, Merritt reminded the City Council that during his term as mayor, “a dam has been constructed near the bridge at a cost of at least $20,000 [about $500,000 in 2025 money], converting this branch of the creek into a beautiful lake. A road sixty feet in width and four miles in extent is now being built around the border of the lake, which, when completed, will be one of the most inviting drives in California. Not less than half a million of dollars has been added to the value of property by this limited expenditure of money, and at no distant day this lake and road will become one of the most attractive features of Oakland.” He didn’t need to say who had paid for the dam — Merritt gave more than three-fourths of the money — nor whose property enjoyed the added value.
The lake as Dr. Merritt envisioned. In this 1899 view from approximately the E. 18th Street boat landing, Merritt’s former land is at left, Sacred Heart Convent at center where the Kaiser building is now, and the oak-crowned bluff of Adams Point in front. The smoke plume is from the cable-car powerhouse and Piedmont Baths. (Wikipedia image)
At the same time the City Council convened a board of prominent engineers and asked them to plan a sewerage system that would make use of Lake Merritt’s water. After careful study of other cities, the board came back in 1871 with a plan of directing household sewage through pipes to a main sewer — so far so good — that would send it directly, untreated, into the Bay in line with standard practice at the time. Uniquely, the main sewer would be flushed twice a day with high-tide water from the lake. That was the scheme. The main sewer would take the lowest route to the Bay, starting from the little stream valley at 20th Street where Snow Park is today.
The work took a while, until 1876. The Main Lake Sewer was a tunnel with five-foot dimensions that ran down 20th and 22nd Streets nearly two miles to the Bay. In their 1883 history of the county, Myron Wood and J.P. Munro-Fraser echoed the prevailing attitude: “The Main Lake Sewer is the most costly and important public improvement ever made in the city of Oakland. . . . The tidal current steadily flowing through it from the east is of sufficient velocity to remove all extraneous matter that may be run into it, while the correctness of the engineering has been demonstrated, and the wisdom of the Board that directed an excellent system of sewerage is fully apparent.”
Despite the boasts, the system was flawed from the start. The lake didn’t have enough water to do the job reliably, and the lake was filling up with sediment. in 1885 the Tribune explained, “There must be maintained a certain volume of water in the lake for sewer-flushing purposes. This volume cannot be long maintained unless the lake be dredged, as each succeeding winter brings down from the creeks, having the lake for an outlet, a large amount of sediment and detritus which is slowly but surely filling up and shallowing that body of water.”
Moreover, the water itself was polluted by the homes around it. The city’s doctors raised a warning. In 1889 the Board of Health wrote, “For years people were allowed to drain their sewers into the lake until it was gradually filled up with a mass of sewage that has covered the bottom of the lake. Instead of a lake of pure water intended to flush the Main Lake sewer, it has become a big cesspool 180 acres in extent.”
The solution was to dredge the entire lake to a depth of five feet. Raising the money and doing the work took many years, and even then the sewer system was overwhelmed as the city grew. The water company took over the job of flushing the sewers, and by the mid-20th century scientifically sound sewage treatment was brought to bear, putting an end to the tide-driven system that had seemed so clever in 1871. Thankfully, Oakland’s sewers are no longer a vexing concern for the city or its leaders (although we’ll need to cope with sea-level rise in coming decades).
In 1945 the Tribune found an old-timer, Alex Rosborough, who recalled the 1870s: “A big square wooden flush sewer ran down 20th Street from Lake Merritt to the bay, above 16th Street Station, which was flushed by water rushing through an outswinging gate at the lake as the tide lowered in the bay.” Today no one remembers it.
At least we still had a pretty lake, right? Eventually it was no longer a cesspool, and the shoreline was built up and it’s part of a wonderful park. Merritt’s dam made it possible for thousands to live and recreate along the lake shore in a beautiful human habitat, but now we must depend on a regulating dam to control flooding.
That dam, functioning today, is in the channel down at 7th Street, while the last congestion at 12th Street, still evident in this 2009 photo, is now gone.
The rest of the channel has been greatly constricted — developed with dredging spoils from the lake — and will never supply the lake properly. Even if the channel were completely open as it used to be, the healthy old San Antonio Slough, once an abundant clamming ground, is gone. Instead we have an artificial basin, and it holds too much water, with not enough tidal turnover, for natural oxygenation to reliably support the aquatic life that wants to live there. Lake Merritt needs a lot of help to stay as healthy as it is.
We still struggle with the consequences of Doctor Merritt’s great scheme.
Oakland Geology 