Archive for the ‘Oakland streams and water’ Category

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Temescal Creek, the lower reach

22 January 2024

Temescal Creek, North Oakland’s largest stream, looms large in local history going back to Ohlone times. The Ohlones had a permanent camp a short distance east of Telegraph Avenue, where the creek’s perennial flow supported a health center. The people would gather in their sweat lodge for lengthy steam baths, then cool off in the stream. Early visitors described the place with the word temescal, a native name for similar facilities in Mexico, and the name stuck to the neighborhood as well as the creek.

Temescal Creek drains a hefty share of the Oakland Hills, including Claremont Canyon, Vicente Canyon, Temescal Canyon and Thornhill Canyon. The county flood control district has this handy map outlining Temescal Creek’s watershed, the land whose runoff provides its water.

In this post I’ll focus on the Bay end of the creek, where the stream is covered up and honored mainly as an idea. I define this stretch as starting just west of the Rockridge BART plaza at Forest Street, the point where it’s joined by its last tributary, Claremont Creek. This part.


Original stream course superimposed on the modern map. Numbers mark features in this post.

In the old days, this part of Temescal Creek flowed down a gentle slope across a wide, grassy alluvial plain―the East Bay flats―between low natural levees. Parts of the creek bed were willow thickets where the Ohlones’ agricultural fires did not penetrate. A large shellmound marked its mouth along the Bay. It’s thought that during Ohlone times, the streams in the East Bay coastal plain didn’t cut into the ground as deeply as today. The changes in land use set in motion by the Spanish and their successors led to fluvial incision and the formation of arroyos. Today the creek runs a good 20 feet below the surroundings.

When the Americans first took over this territory, they used the stream to establish property lines but otherwise left it alone, except to build bridges over it on the main roads. Then in 1871 “Captain” Edward Wiard opened the Oakland Trotting Park on his land near Shellmound Park, as seen in this 1876 map, and chose to cover the creek. That was the first culverting of the stream. By that time, its headwaters had been harnessed by Anthony Chabot’s dam for the Contra Costa Water Company, Oakland’s first municipal water provider. Farms, factories, canneries and other industries located near the creek in the next decades. They found its natural floods inconvenient.


Detail of the King map, from the Rumsey collection

Today the entire lower segment of Temescal Creek is encased in a concrete channel, bound by human needs. Most of it is covered up entirely. This part of the creek has some major constructions: freeways, the eight-track-wide railyard of Emeryville, Emery High School, the Children’s Hospital complex at MLK Boulevard, the Logan development at Temescal, the Rockridge BART station. These projects had the money to underground the creek and can’t be undone. The county flood control district entombed the rest for completeness’ sake, and between that agency and the home owners, the creek in their back yards will never be exhumed.

That leaves the creek to be memorialized by symbolic acknowledgments. I’ve visited them all to write this post. I’ll start in Rockridge and end at the Bay.

1. The Rockridge-Temescal Greenbelt, also known as Frog Park, has turned a 2000-foot stretch of culverted creekbed between Hardy Park and Redondo Playground into a rich neighborhood asset. In Hardy Park, at the upstream end, is a large grate over the culvert where you can stand and listen to the water.

The rest of the greenbelt consists of a secluded path with understated exhibits and a faux streambed that can be filled with running water when the pumps are activated. This is the part behind the DMV building, site of the Lusk Cannery in the 1880s.

2. On Telegraph Avenue at 51st Street is this utility box with a stream-centered mural.

3. Just the other side of the PG&E substation, on Shattuck Avenue is this installation that deserves more visitors than it gets. The site was once a trolley yard.

The Children’s Hospital complex, a little farther west across the freeway, originated in a grant of land from the heirs of Solomon Alden, whose lavish farm estate straddled the creek and supplied Lusk’s cannery.

All of these places were part of the village of Temescal around the turn of the last century. Oakland annexed it in 1897, and you could say the town has been hidden as well as the stream. A 2012 Oakland North article has more detail on the Temescal segment of the creek.

From the hospital the stream culvert runs between the back yards of homes. The butt end of Genoa Street offers a glimpse. Large trees also mark the stream’s course, as they do elsewhere in Oakland. From here west, the stream flows across nearly level ground.

4. Adeline Street is in Emeryville here, barely west of the city line. The creek is recalled at 5200 Adeline in the Bakery Lofts development, a former factory that once straddled the creek. The creek can be heard through the pipe, which opens into the culvert.

5. The Oakland-Emeryville border turns west here and wanders with the creek for a couple of blocks. This segment is occupied by attractive little Temescal Creek Park, a joint project of the two cities. Here too are steel grates, near the east and west ends, where you can hear the stream below rustling.

6. One of Emeryville’s community gardens occupies a parcel on top of the culvert at the east end of 48th Street.

7. A short distance west on San Pablo Boulevard, facing Emery High School, is this little treatment honoring the creek.

8. Beyond more culvert about a half-mile west, the stream emerges at Horton Street in Emeryville’s exciting new Horton Landing Park, a pedestrian landmark featuring a dramatic bridge over the railroad tracks and connections to the Emeryville Greenway. Though final landscaping is still in progress, I think it’s already worth a trip from anywhere in the Bay area.

Crossing the bridge over the wide railyard, between its walls of new buildings, feels a little like going through rocky hills over a river gorge. The footpath itself curves, a nod to the buried stream beneath.

The exposed creek bed in this stretch is naked now. There may be plans to revegetate it, perhaps with native willows again.

The educational memorialization park west of the bridge is a meandering avenue of chiseled granite and etched glass exhibits about the Ohlone people: how they used to live and what they’ve gone through. It’s a starting point; the tribes are still here and need from the rest of us more than these exhibits.

The city’s park ends at Shellmound Street, at the old shoreline. The Emeryville Shellmound was the greatest topographic feature in the area, and the site is central in the little city’s history. As with the creek, the shellmound is honored more in its absence than it was during its presence.

9. The stream continues under the freeway to its current mouth on the Bay, free at last.

The coast here is part of the Emeryville Crescent State Marine Reserve, now just a park in embryo form. The mouth of the creek is not easily accessible yet; the birds and advancing pickleweed seem to like it that way despite the trash and traffic.

This is not exactly where the historical stream ran, but it will have to do for the next few centuries. Perhaps later generations will find opportunities to spring Temescal Creek from its prison. On the geological time scale, creeks like this roam about the landscape as they slowly build up the coastal alluvial plain.

Posted in Oakland geology walks, Oakland streams and water | 2 Comments »

McCrea Park, a closer look

30 October 2023

I led a walk around the headwaters of Lion Creek this weekend, visiting the Lincoln Square serpentine and landslide, the Alma Mine and Crusher Quarry sites, and the Hayward fault over at 39th Avenue (one of the seven stations). One of the best parts of the trip was revisiting the creek at McCrea Memorial Park and Oakland’s casting pools, an unsung civic amenity for our fly-fishing population.

The casting pools were constructed in the late 1950s. The land was part of the city’s Leona Park, which extended from here across Mountain Boulevard and up Horseshoe Creek. To all appearances, this site was a natural floodplain at the time, bare of vegetation. They did a beautiful job, and a fringe of trees was planted around the pools that soon provided the atmosphere of seclusion that still prevails. The next stage of developing the area was to build a set of ponds downstream where you could fish for actual trout, not just practice flycasting.

The trout ponds were a city concession, managed by a caretaker from the little house across the creek. Barratt Wells, a Piedmont native who also operated a trout pond in Tilden Park, was awarded the ten-year contract in 1959, but he died in 1963.

There were three ponds, stocked with trout each year. The Oakland Tribune reported, “One pond contains fish from six inches up and is for use by children over five and non-expert adults. A second pond is for toddlers under five, while the third, with a completely natural setting, is for the experts, who will fish for trout up to three pounds.” You paid for what you caught.

When the route 13 freeway was pushed through in the 1960s, it split the park into two pieces, Leona Heights Park on the east and this part, named George E. McCrea Memorial Park in 1962, on the west. An obscure pedestrian overcrossing connecting the two parcels is the route we took.

(George McCrea owned this land, and his son gave it to the city. He also owned a historic bit of land farther north by Holy Names College, where he had a house. More about that in a bit.)

The fishing program ended around 1975, and the ponds soon filled with silt. Police volunteers mucked them out in the summer of 1981, and the state supplied the park with trout. The police association ran popular fishing sessions for kids there every summer through at least 2009.

The 1960-era design was pretty good at fitting three working ponds in the narrow space available. Here’s how it looked in the spring of 2014, the first time I came here.

First of all, everything is concrete, even the creek bed itself running along the right side. The wall in the front has two cutouts, the big one on the right and a little one on the left. Timbers and steel plates are inserted over these gaps to regulate the flow through them, and the space in the front is the first trout pond. The second pond is just past the redwood tree (which was planted ca. 1960) and the third one, much larger, is behind it. Here’s another view that shows the little cutout better.

It all looks tidy in these views, but the ponds held stagnant, weedy water at the time and a pair of ducks.

This weekend, nine years later, the lowest pond looked like this (view upstream).

Nice enough. Peaceful. But no good for trout. And here’s the uphill side again. The middle pond isn’t even a pond any more.

I had so forgotten the middle pond that I was enthusing to the group about the lovely wetland being watered with this ingenious system. I regret the error. And in the front you can see that the first pond is filling up with sediment too, not to mention the creek bed behind it.

Lion Creek is not a major watercourse, yet you can see how dynamic streambeds are. To build and maintain a park in one is an expensive, ongoing project, and I think the city should consider how to let this picturesque ruin-in-the-making find its way back to a state that’s easier to manage. The casting pools will be okay for many years to come.

Back to George McCrae. His land up by Holy Names was the Ohlones’ old ocher mine, and the chair-sized boulders placed around the trout ponds look to be the same stuff. They don’t look the same because they’ve acquired a shaggy coat of lichens in the moist environment, but they’re bright red inside. Admire them too when you visit.

A final treat in McCrea Park is up near the entrance.

These sandstone blocks are pieces of Oakland’s first high school, built in 1871. I’ve documented them on Lakeshore Avenue and near Lake Merritt, and it’s always a pleasure to find them.

Posted in Oakland boulders, Oakland streams and water | 5 Comments »

Vicente Canyon

16 October 2023

Claremont Canyon and Temescal Canyon are big excavations into the rising Oakland Hills, and each is a traffic corridor. Between them is a smaller valley — a gulch, really — that I think is pretty distinctive, enough so to merit the title of canyon. I name it Vicente Canyon, after the stream running down it, Vicente Creek. All three canyons feed their runoff to Temescal Creek, as shown here in the county’s watershed map.

Take a close look at it (click it to see full size). The land surface is shown as a digital elevation model, and without all the distracting street names and such, some things are obvious. All three canyons are defined by the Hayward fault, which runs from top center to lower right. The hills on the east side are being pushed up, and the ridgetop is around 1300-1400 feet elevation. Vicente Canyon has only a slightly smaller elevation range, but it’s much shorter; that is, its slope is steeper. The two bigger canyons are long. Their streams, Claremont Creek and Temescal Creek, have stretches that are almost level, but not Vicente Creek. It’s working harder than its neighbors.

Here’s a thing people may not get about streams: they only erode and cut down their own narrow streambeds. Other than that, all they do is carry away what falls into them. As the Oakland Hills rise, the streams that drain them are compelled to keep cutting straight down to the level of the land at the fault, which is the local base level. This is a very effective process, geologically almost instantaneous — for example, you’ll notice that wherever tributaries join a larger stream, they always meet at the same level. The big stream is the base level for the little one.

Vicente Canyon has extra-steep walls that are ready to slide, and as I’ve explored this valley in recent weeks I’ve seen a lot of landsliding. Here’s a little example from high up in the catchment, on the unbuilt extension of Kenilworth Road.


A scoop of hillside has slumped and rotated on a curving underground surface. The tree died when its roots were torn off.

Down by the creek itself, the slopes are even steeper. This bit of Westview Drive suffered a fresh debris slide (what’s typically called a mudslide) just last winter, next to an older one.

The state’s official geologic hazard map corroborates me. Here’s the area that includes Vicente Canyon. The blue tint signifies areas at high risk of landslides.

The diagonal strip is the official “earthquake fault zone” defined by the state and the black line inside it is the trace of the Hayward fault. With that in mind, look at the digital elevation model of the same area.

See how the stream bends as it approaches the fault? It’s a great illustration of what the fault does to the landscape. The bottom side is moving leftward an average of about 10 millimeters a year. (The uplift part I referred to earlier is more like 1 mm/yr.) Humans can’t perceive movement that slow, but streams feel it as surely as we feel an escalator.

The rocks in Vicente Canyon are almost entirely mudstone of the same vintage as the rocks of Shepherd Canyon.

They’re rarely seen, though. They quickly turn back into the clayey sand they started from, as exposed in this excavation on Westview Place.

Once the creek crosses the fault, everything changes. The rock there is Franciscan sandstone, somewhat harder. The stream becomes a rocky gorge that winds through wooded yards for a few hundred meters to its junction with Temescal Creek, which is now culverted. The neighborhood is different, but not without its own charm.

All of Oakland’s high hill neighborhoods stack elaborate houses along narrow roads on steep, not-too-stable slopes, but because of its underlying configuration, the Vicente Canyon neighborhood is even more like that. At its best it presents a picture of architectural and engineering heroics in a lovely woodsy frame.

And especially along the canyon’s upper walls, the views across the fault to the San Francisco Bay basin are luxurious.

But the Vicente Canyon Hillside Open Space, a couple acres of oak woods between Vicente Road and Gravatt Drive, is a fine place for spry visitors. The locals manage a foundation that tends the land as a fire barrier.

Its benches have million-dollar views and none of the hassles of living up there.

Posted in Hayward fault, Landslides, Leona volcanics, Oakland geology views, Oakland streams and water | Leave a Comment »

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