Stream bank instability and siltation are common, and the threat of landslides has discouraged urban development in the hills.

Several minor work projects were undertaken the 1970s with trail clearance and stream bank restoration.

A line of prepared defenses lined the stream bank, but only 10 of the planned 24 cannons were installed in the redoubts.

Most specimens have been collected over shallow, fine gravel shoals with moderate to swift flow, usually near the stream bank.

Stream bank instability and siltation are common, and landslides deter urban development at higher elevations.