Through the years I’ve come many times to the quiet, however as soon as eventful Reservoir Hills neighborhood, on the Glenview aspect of Sausal Creek and south of I-580. This weekend I led a stroll for the Mates of Sausal Creek by way of the realm, which gave me the prospect to dig slightly deeper, therefore this put up.
This compact neighborhood incorporates two options of geological curiosity: Central Reservoir and the McKillop Highway landslide, formally disguised as William D. Wooden Park. The reservoir occupies slightly stream valley that feeds Sausal Creek, and the landslide has been undermining the excessive financial institution of Sausal Creek proper subsequent to it. Each are older than they appear, and each are altering.
The reservoir started first, so far as I can inform. The Contra Costa Water Firm, within the Eighties, set their sights on this valley as a result of it was effectively located for a secondary reservoir. On the time the corporate’s water was horrible stuff, inexperienced and smelly, they usually wished to make a “settling reservoir” there to carry water from Lake Chabot and Sausal Creek till it clarified a bit. The land, a few of which had been a part of the property of Capt. Levi Stevens, turned out there after his demise in 1882, and the water firm started to dig a big basin however then stopped work for a few years. A few of the grime, the corporate’s chief engineer later testified, “was used to fill some tons close by.”
Work resumed in 1909 after the Peoples Water Firm acquired the property, and the reservoir entered service in 1910. At the moment, metropolis engineers had seen some landsliding to the east, on the slope overlooking Sausal Creek throughout the low ridge between the 2 areas. That ridge was subdivided and developed within the late Twenties, and the residents of the brand new streets, Sheffield Avenue and McKillop Highway, loved one among Oakland’s most interesting views.
Repeated landslides started to have an effect on the slope, beginning in 1935 and lasting into the Nineteen Fifties. Every time a couple of extra homes on McKillop Highway have been destroyed, residents demanded motion, and town sponsored research. Lastly within the Seventies sufficient cash was assembled to amass the ruined land and sculpt it right into a easy park with a stage area and an engineered slope that’s held up effectively because the park was devoted in 1976. The central half of McKillop Highway was erased, however each ends stay.
Thirty years later, the landsliding resumed, this time on the downstream finish of the sooner failure. The 2006 slide took out one other home and left a large number that town hasn’t touched since then.
As we speak you’ll be able to’t see this as a result of it’s all overgrown. The close to a part of the property, owned by town, is used as we speak by a small plant nursery, Wildheart Gardens. After I was there this weekend, I used to be instructed that the slope continues to be giving approach.
At this level will probably be useful to look intently on the floor, as revealed by lidar surveys and the ensuing digital elevation mannequin which ignores the bushes and buildings to point out the underlying land floor.
Derived from nationalmap.gov; north is to the fitting and illumination is from the higher proper.
It exhibits the clear traces of Wooden Park and the jumbled ruins of the 2006 slide to its left. Two homes stay on the east aspect of McKillop, between the 2 slides; they have been red-tagged in 2006 however not condemned.
In any disaster, folks will attempt to determine the way it occurred and, if legally doable, who guilty. The Central Reservoir was at all times a suspect, however I feel a geologist will inform you that this was unlikely. In any case, the lawsuits that adopted the 2006 slide have been rejected by the jury. If I have been licensed to follow geology in California, I might have predicted that.
Many causes are doable, they usually can overlap. The world the place the slides started was a part of Capt. Stevens’ property, and he was an incredible lover of unique crops who tapped the creek to water them, and he most likely moved some grime round. The creek is of course eroding its banks and undermining the hills that line its floodplain. The reservoir did and does leak to some extent by way of its concrete and asphalt lining. The Eighties excavation spoils might have been dumped alongside the highest of the ridge the place McKillop Highway would later run, creating weak floor and loading the slope. Houses constructed on hillsides add their weight―and their house owners’ watering habits―to the slope. Poorly designed roads have related results. And landslides develop all by themselves as a result of their edges are unstable scarps.
Given a selection amongst these potentialities, I’m inclined to say “all the above” and go away it at that.
The reservoir, by the best way, might be changed in the course of the subsequent decade. The positioning might be occupied by three massive metal tanks, and the entire water system will work significantly better. In regards to the slide space . . . we’ll see.
