Oakland Geology

Earlier this year I took a peek at the mitigation work going on at the former pyrite mine at the head of McDonell Street, in the Leona Heights neighborhood. The workers had laid down lovely geofabric, seeded grass and paved the creek bed with boulders. They were also patching infant gullies. I predicted it wouldn’t last. Sure enough, on Saturday large expanses of black plastic were shielding parts of the locality.

Farther down, the patchwork had massively failed.

This was after a normal December rainfall. We’re looking at El Niño rainfall during the rest of the winter that will be substantially above average.

On the good side, I can report that the water downstream at Twitter Court wasn’t an ugly orange. Whether that’s due to larger runoff volume or success in muffling the acid drainage, I’m not qualified to say. Think positively as you walk past the mine site on your way up the fire road into Leona Heights Park.

It will always be an instructive and rewarding hike.

This entry was posted on 4 January 2016 at 8:02 am and is filed under Oakland hazards, Quarries and mines. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.