Wednesday, June 9, 2010

Rock Bottom Creek

The excessive rains we’ve been having this spring have kept the ground water recharged, so the creeks have maintained a nice flow. By this time of year, the creeks are usually slowing down and you’ve lost the sparkling ripples and the gurgling sounds of the waterfalls. If this keeps up, it will be an exciting year for observing aquatic insects. This particular creek is the smaller of two that eventually join at the center of Blue Jay Barrens.

The majority of this tributary flows on top of bedrock. The inconsistencies in the bedrock layers have allowed for the formation of numerous waterfalls, riffles and pools. The rocky substrate tends to limit the amount of plant growth within the stream channel.

A rock lined bowl has formed at the base of this tiny waterfall. This section of stream is in the upper reaches of the watershed and typically goes dry each summer. Fish rarely penetrate this far upstream, so these places are prime breeding areas for aquatic insects.

Clean gravel piles up downstream of the pool. These are primarily limestone pieces with a little bit of shale mixed in. As a consequence, the water usually has a pH between 7.5 and 8.0.

The absence of fish also benefits the salamanders. Several salamander larvae are searching the gravel bottom for insect prey. The rate of stream flow indicates that these larvae have plenty of time to become land dwellers before the stream becomes dry later in the summer.

Limestone bedrock just under the sod creates a state of stability in the banks. This means that chances are low of this section of stream meandering. Gravel in the streambed tends to move, but this section of stream enjoys a degree of permanence that’s typically not expected.


  1. This wonderful little tour reminds me of walks in the woods with my friends as a child. We would wade in the streams and catch salamanders.

    Thanks for your always great images.


  2. Lois - Sounds like you grew up in a nice place. Most of my childhood was in a more urban environment and the things I found in the creek were less elegant than your salamanders.