Re: Yosemite Master Plan. Chapter 0

We have a month or so for public comment, I'd like to know whether the MP takes the Valley water table into account.

Setting the water table will control the landscape for hundreds of years.

I understand that a rock barrier was blown up to drain the Upper Valley, and that a dam was built and subsequently
blown up at the Valley mouth.

Setting the table(s) to that which existed at the end of the Little Ice Age (1850) would drown a lot of pine trees and increase
meadows to around half of the Valley floor instead of the present 6-7%. Mirror Lake could be a lake again?
Restrict most human construction and all occupation to the bath-ring of forest between the river/meadows and the fall zone.

The wild Merced river gets breathing room, few man-made objects lost in a 1000-year flood, & the visitor viewscape
will be similar to that enjoyed by John Muir, & all the other pioneers.

Quote
wagga
Setting the water table will control the landscape for hundreds of years.

I don't think there's any way to change the water table now. The only diversion is the Valley's water system (you can see the large tank from Sierra Point).

Taking it to the absurd, you could build a 300' dam at the Valley mouth and it would raise the water table.

Talking about absurd: Hetch Hetchy.

Quote
wagga
Taking it to the absurd, you could build a 300' dam at the Valley mouth and it would raise the water table.

Yes, but that won't happen (now).

Quote

Talking about absurd: Hetch Hetchy.

Times have changed.

Apparently, at some time in the past, an upper, cross-valley underground ridge/moraine entity was lowered to reduce mosquito problems.
At the mouth of the Valley, a small dam (9'?) was built to raise the water table, kill the trees and make grazing better for the sheep.

The point is that the water table has been adjusted, and that it largely controls the macro-ecology, and hence the appearance of the Valley.

The Valley we see today is quite different from that which stole John Muir's heart.

I think that a lot of the difference is due to the fact that the valley was burned off every year keeping with native American land management methods. Another thing that caused a difference throughout the park is 100 plus years of fire suppression.

---

Old Dude

Quote
eeek

Quote
wagga
Taking it to the absurd, you could build a 300' dam at the Valley mouth and it would raise the water table.

Yes, but that won't happen (now).

Quote

Talking about absurd: Hetch Hetchy.

Times have changed.

Thanks to the kind of people who inhabit this board...

---

Illegitimus nil Carborundum