1953 Isabella Dam on Kern River northeast of Bakersfield, CA

(Satellite)

Steve Schott, Oct 2023

The USACE finished a 17-year upgrade project in 2023. It was delivered underbudge at $320m.

4:15 video @ 0:38

@ 1:22

The new spillway being constructed.

hdrinc

This article provides a cost figure of $600m.

enr, paywall, Photo courtesy of USACE
"The Isabella Lake Dam safety modification project will address overtopping, seismic and seepage issues identified with Isabella Lake’s main and auxiliary dams to reduce the likelihood of dam failure."

2:25 video @ 1:42

Before this project was done, the reservoir was kept below 2/3 of its originally designed capacity. [wakc]