Gruhn's Dam

Went down the beach today. Dad was off watching people clamming. I built a dam. If I weren't a moron, I'd have taken a picture of the site before I got there and a couple during construction.

Of course, I built the dam across an existing water flow. The sand down the beach is tan on the top but just underneath, a deep slate gray. So I peeled off the sand to either side of the stream downstream of the dam. This shows up as three stripes running from the dam - black sand, tan sand, stream bed, tan sand, black sand.

This is looking up the stream bed towards the face of the dam.

The whole scene.

Closer.

View from on Gruhn Lake. Looking toward the center of the dam.

The full drama of a collapse. Here, the dam has become too saturated with water and the front face starts to slump down.

Just a little further. Watch out for that bit at the top. Remember, there is still water flowing into the lake.

And it's through!

Repairs. And a new water spot on the lens. I repaired it, because the break wasn't where I wanted it.

Here, a small bit of water has found a channel over the top of the dam. A little more water flows into the lake and the flow through the breach increases. The flow starts to take the dam with it and in just a couple seconds, there's a deep cut.

Almost no time after the first breach, and the view from down stream is of a massive gash in the dam face and a rushing torrent. Remember, just seconds before this picture was taken, the water in the lake was level with the top of the dam.

The material from the dam soon blocks the initial path of the flood and the waters spread to either side, filling up the lowlands around the old stream bed.

Compare this to the scene of placid tranquility from just a few minutes before. Devastation.

Maintained by Peter M. Gruhn.