Thursday, October 12, 2017

A Hike to the Powder Works dam

The wooden dam (upper left) and concrete diverter (mid-right)

This past Sunday, I joined a walking tour organized by Lisa Robinson of the San Lorenzo Valley History Museum.

Besides Lisa, our local expert guides included lime industry expert Frank Perry and SLV historian Fred McPherson (not to be confused with Freds of the Santa Cruz Sentinel family).

Our goal was the remains of a dam that once held back and diverted river water into a long wooden flume, into a tunnel through the intervening ridge, and out into another elevated flume for eventual use in powering machinery at the California Powder Works. The 60-ft drop provided plenty of water pressure.

For those unfamiliar with the Powder Works, the SCPL website has an informative series of articles by Barry Brown, at: https://www.santacruzpl.org/history/articles/508/ The photo above is from the "CPW dam" article.

We started from the Rincon parking lot on Highway 9, formerly the location of a lime-production operation. The structures are all gone or buried, but evidence remains if you know where to look. Lisa and Frank brought photos from the early 1900s, when the lime operation was still busy.

Following the Henry Cowell Redwoods State Park trail (on an old road) down to the San Lorenzo River, we speculated about the original purpose of the road. Was it connected with the lime operation, or was it to provide access to the dam/flume operation? Was it a fire road built for the state park, or was it something else we couldn't guess?

Turning north along the river, it's about a mile to the dam site. The wooden dam and other wooden parts are long gone, but much of the concrete base of the flume diversion wall and a concrete riverside retaining wall remain. We found iron parts of the mechanism that raised and lowered the flume gate.

Back south along the river, we found traces of the flume, and tried to guess where the tunnel began. The opening, about 10 feet above river level by that point, has been erased, but it's possible to approximate where it must have been. Closer examination might reveal some of the rock to be the hard granite that slowed the diggers when they reached the center of the ridge.

On the way back up the steep road, I learned a lot from Fred about the local ferns and other plants we saw along the way. Great fun!