Archive for the ‘oakland water’ Category

Central Reservoir

8 April 2013

Central Reservoir is operated by EBMUD, but it’s much older. It’s the weird-looking steel-covered field north of Sausal Creek. This is a view looking over the reservoir from Ardley Avenue toward the hills.

centralrestop

That’s the Altenheim on the left, across I-580, and of course the LDS temple with Redwood Peak behind it.

The reservoir was built in 1910 by the People’s Water Company, which took the existing valley of a Sausal Creek tributary, hollowed out the top of its watershed and made an earthen dam. Later EBMUD assumed control of it and upgraded things considerably. However, landslides plagued the steep west bank of Sausal Creek directly east of the reservoir starting in the 1930s.

The latest set of slides, in 2006, led to a tangle of lawsuits initially aimed at EBMUD and blaming leakage from the reservoir. The lawsuits were consolidated and went to a jury trial in 2012, with Alameda County as the main defendant and the damaged land owners (two homeowners and a church) as the remaining plaintiffs. The jury found for the County. None of the media that announced the lawsuit bothered to report the outcome, and the City of Oakland hasn’t bothered to clear EBMUD’s name, but the jury dispensed justice as designed.

For 17 MB of geotechnical detail, see EBMUD’s Central Reservoir Seismic Final Report, issued in 2008. As far as engineers can tell, even the Big One on the Hayward fault won’t break the dam. But if I lived downstream, I’d keep a close eye on the dam after a truly major quake and be ready to relocate. And in the aftermath, that emergency water supply may save our lives.

Headwater landscaping

26 March 2013

The advantage of living in the highest hills is that there’s no one upstream from you. At the same time, hilltop dwellers may find it easy to forget what it’s like downstream.

gravelwash

This lot sits at the head of a stream valley at the edge of a regional park. The large expanse of impermeable pavement collects rainwater, and the terrace above it discharges more runoff in a large drainpipe. Ordinarily the ground would absorb most of the water and release it gradually, the way that trees are used to. Instead the flow that results here is strong enough to carry away a lot of gravel. Oh well, call in another truckload.

Turn around and track that water and gravel over the property line into the Regional Open Space. With the extra water, the stream is already cutting a deeper channel into its valley. As the years go by, the valley walls will slump into the stream and the trees will fall with them. A big wad of sediment now working its way downstream will clog the habitat below, smothering the bottomland and its ecosystem. Meanwhile the erosion of the stream valley will work its way headward. Eventually, within a lifetime, the spreading collapse will reach the edge of this large lot (and the neighbors’ lots) and whoever owns it will have an expensive problem. This pristine street may disappear from the map, like others before it in the Oakland hills.

I’m not giving a professional opinion here; it’s obvious to common sense. The landscape of the hills is fragile, but expert advice can make living there much more sustainable.

23rd Avenue valley

26 February 2013

Between the stream valleys occcupied today by 14th Avenue (originally named Commerce Street) and Fruitvale Avenue (Sausal Creek) is a subtle little valley that once had its own little creek. Now 23rd Avenue runs up its former course, diverting the street from the grid so typical of the rest of the neighborhood. The creek is shown on the 1877 map entering the Bay where the Embarcadero Cove Marina sits today. There seems to have been a shellmound a little south of there.

This view is looking up Foothill Boulevard where it crosses the valley. This is at the top of the marine terrace and the foot of the Fan. You can pretty much always tell where the Fan starts by following Foothill. The geologic map shows the valley splitting here with a spur running due north for a few blocks, filled with young alluvium.

23Av-Foothill

This is looking across the valley farther uphill, on E. 17th Street where Garfield Park is. The valley is a bit deeper here, and it continues to deepen as you go uphill.

23Av-E17St

At 23rd and 23rd the creek split, with its northern fork running where Highland Avenue is today. The main fork continued straight, along 23rd Avenue, and petered out by E. 30th Street right next to the Central Reservoir, which is in the Sausal Creek watershed. The stretch where the divide between the two watersheds is most pronounced is occupied by a street named, unsurprisingly, Grande Vista.

This creek is entirely covered today.

Sneak creek peek

22 February 2013

Sausal Creek has escaped culverting in a large part of its course. Between Dimond Park and the freeway, it mostly runs through people’s back yards, but you can spot it looking downstream from MacArthur Boulevard across from Canon Avenue:

sausalsecret1

. . . and farther down, looking upstream from a spot at the intersection of Dimond Avenue and Montana Street.

sausalsecret2

It’s culverted from here all the way down to the end of Hickory Street, directly below the miserable house on McKillop Street. Maybe it’s safer to say that the creek is covered, because even this open stretch has walls hemming it in.

Elmhurst Creek

30 March 2012

At the tower overlooking San Leandro Bay in the Martin Luther King Shoreline park, you can see the confluence of five Oakland creeks in four outlets, Peralta Creek on the north, followed southward by the combined mouth of Lion Creek and Arroyo Viejo, then Elmhurst Creek, then San Leandro Creek. Little Elmhurst Creek doesn’t get a lot of love, but this is it.

elmhurst creek

It runs past the south side of the Coliseum complex—did you know that the Coliseum is nearly surrounded by streams?—and it emerges from underground culverts just west of San Leandro Boulevard near 81st Avenue. What strikes me about that spot is that it’s the truck stop where sits the colorful Estrellas de Sinaloa diner, which appeared like a mirage on the gray day in 2008 when I walked the length of Oakland from the San Leandro BART to the Berkeley line on Shattuck Avenue.

estrellas sinaloa

The Oakland Museum’s watershed site has little to say about the creek, only that its headwaters were a willow thicket at International Boulevard whose drainage has now been diverted to its bigger neighbor, San Leandro Creek. Looking at the contours on the map, I can surmise that the spot was somewhere between 90th and 98th avenues, right where the historical town of Elmhurst once sat. Imagine the little farming village that Elmhurst used to be in the late 1800s.

Now I must eat at Estrellas de Sinaloa (how’s the food?) and walk to the corner to pay my respects to the creek.

The Pill Hill/Fairmount ridge walk (#20)

29 December 2011

This hills-and-paths walk is number 20, “Broadway and Oak Glen Park,” in Charles Fleming’s Secret Stairs East Bay. This is not a bedrock walk, like the previous ones I’ve featured, but a landform walk. Let’s start this time with the topography.

walk 20 topo

This walk starts in the bayside flats, crosses two hills and two streams, and returns from the side of a third hill. The first hill is Pill Hill, and the second (Fairmount ridge is my name for it) and third are lobes of the Adams Point upland. These are parts of a larger structure that is central to Oakland’s character, an ancient Pleistocene alluvial fan. Here it is, marked “Qpaf” on the geologic map.

walk 20 geologic map

This walk takes in the leftmost edge of the fan, crossing two valleys of the Glen Echo Creek system which dissect the fan. The creek feeds the narrow west arm of Lake Merritt.

All right, here’s the route with the locations of the following photos.

walk 20 route

Here’s the view up Hawthorne Avenue to the edge of Pill Hill. The land west of the fan is a modern alluvial flat with almost no topography to it beyond subtle levees along the modern Temescal Creek and the notorious filled-in marsh that once underlay the ill-fated Cypress Structure in West Oakland. The Pleistocene fan has fairly abrupt edges like this all around it.

pill hill

As you go over Pill Hill and Summit Road on its spine, take a close look at the topography ahead of you. The near ridge is Fairmount ridge, made of Pleistocene alluvium, and the distant hills are Cretaceous and Tertiary sedimentary rocks. The eminence at the foot of the high hills is the older Franciscan block that underlies Piedmont and upper Rockridge.

pill hill view

The walk goes down into the valley of Glen Echo Creek. Brook Street is named for the Broadway branch of the creek, which is culverted under Mosswood Park and runs open to the sky in the backyards here. This shot is at the foot of 30th Street.

glen echo creek

If you go upstream a little ways you can spot the culvert where the two branches join.

glen echo creek

Next we climb the other side of the valley up a long flight of stairs, then turn right and follow the ridge top, along Fairmount Avenue, for a ways. A detour of stairways leads to Hamilton Place, at the toe of the ridge (the new Whole Foods place cut into that toe; unfortunately I never got a good look at the cut). From here we look across the next valley, which I might as well call Harrison valley.

harrison valley view

This valley has a well-developed profile, but apparently it never had a permanent creek. The Oakland watershed map shows only a culvert here. Anyway, we walk up the far side of this valley and return west on classic Perkins Way, where we can look back at the other two ridges.

perkins way

Back up on Fairmount ridge, we stroll up quiet Kempton Avenue, where this nice driveway wall of California mariposite lives.

mariposite

Soon enough we find ourselves again at the steep edge of Glen Echo Creek valley. If you limit yourself to walking, Oakland is really quite a rugged place.

kempton avenue stairs

At the bottom is a precious remnant of early Oakland’s streambeds, Glen Oak Park. An old concrete bridge crosses the stream, and if you have time to stroll up and downstream there are some fine buildings here too.

glen echo creek

I would be remiss not to mention that a little farther, at the foot of Piedmont Avenue, is a good sushi place, Drunken Fish.

Radio Beach

8 November 2011

Radio Beach is Oakland’s nearest thing to a natural beach. It’s city land, on the north side of the Bay Bridge approach past the toll plaza. There is no lonelier or prettier spot on Oakland’s waterfront. This is the view toward the bridge as you enter the beach.

radio beach

This was near low tide yesterday, and the mudflats stretching all the way to Emeryville were tempting. Here’s the view back from the other end, with some of the radio towers.

radio beach

And here’s the view out, with Mount Tamalpais, Angel Island and the Tiburon Peninsula on the skyline. Click the image for a 1000 pixel version.

radio beach

The sand is very fine grained, given the energy of the waves and the available sediment in the Bay. It collects here where a little extra wave energy gets focused, against the buttress of the bridge approach. Not a super beach, but a real one.


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