My usual steep bushwhacking didn't seem very inviting under those conditions, so I went up the Four Mile Trail to poke around. I was surprised to see that the trail over to the water works (which had been growing shut from brush in recent years) was all nicely trimmed again. So was the decoy trail next to it, which goes nowhere, but which is purposely made to look more inviting.
You can learn about the old water works here:
http://yosemitenews.info/forum/read.php?3,48306
Here is a view looking back towards the Four Mile Trail. In the distance you can see the trail cut in the brush where it goes around the ridge to the Four Mile Trail, which is by those large pines.
From the same point, looking ahead, you can see the pump building.
Last year I had been up there, and and the works were obviously out of use. Breaks from falling rocks in the plastic feeder pipes, and a general look of decay inside the pump house, though it was clearly being kept in a state where it could be repaired if the new well up at Glacier Point failed. Perhaps that new well has been a disappointment in this year of drought, because now a brand new pump has been installed in the old waterworks.
The new pump is much smaller than the old one, which itself was much smaller than the chassis of an even older one whose pieces used to be lying about. That makes a lot of sense, because the two hotel buildings at Glacier Point are gone, as is the old Glacier Point campground. The fancy restrooms at the point are essentially shut down, for a dumb legal reason. The old comfort station and horse trough at Union Point is also gone. So all that this new pump really has to do is keep the big water tanks topped up in case of fire, and feed the drinking fountain by the parking lot. Still, it is a long way up the hill to those tanks. You can see on the pressure gauge a red pointer at 400psi, which is probably the maximum working pressure of the system.
In the photo, the vertical blue pipe is open at the top, and seems to be the overflow from a (hopefully never used) over-pressure burst diaphragm. You can see how much smaller the new pump is by observing the size reducers where the input comes around to enter the bottom of the pump, and then dinky little pipe (my arrow) that comes out of the brass pump manifold and which must be expanded again to feed the steel pipes that head up the hill.
So the mechanical works are in great shape, and the site has been cleaned up of a lot of old hardware. Unfortunately, the pump building itself did not receive the same attention. The stone walls and the roof (which is interlocking slabs of reinforced concrete, with a cement overcoat) are in good shape. Unfortunately, the large wooden lintel holding the roof, and the door and window frames, have suffered from 80 years without paint or maintenance. The entire door frame has fallen inside, and the windows are not far behind. Since this is an historic structure by park definitions, I hope that someone comes to fix it up next year. When that wood beam crumbles, the roof will come apart and the walls will start to weather away.
The other side of the water tank is fed by low pressure plastic pipe coming from the spring over by Sentinel Rock. To avoid a rib of rock, it drops considerably below the pump house before coming back up in what is called an inverted siphon. The stretch of pipe near the tank is very steep, and it was always a problem to climb next to it without touching the plastic pipe. The work crew has left their own cure for this problem:
On the horizontal run down below, they have left a bunch of extra pipe to fix what will invariably be smashed by winter slides:
The actual pipe run should be covered with dirt, but some bits get uncovered by erosion. So not all of the white pipes that you see in the photo are spare pieces or broken segments.
At the moment, all the drain plugs are out, to prepare for freezing weather.
It rained all Thursday night, then got cold. By 11:00 on Friday it had warmed up to 35 degrees, and the bushes were only somewhat wet, so I went over to look for lost switchbacks on the Old Big Oak Flat Horse Trail. It was a nice clear day, but short. By 3:15 the sun had gone down behind Inspiration Ridge. For info on the horse trail, abandoned in 1874, see:
http://yosemitenews.info/forum/read.php?3,48394
