The technique of photographing moving water with long exposure has become somewhat of a cliche, but nevertheless, it is a technique that that creates interest in an otherwise uninteresting shot. I am always intrigued by patterns and textures.
The first image below was captured of Tuscarora Creek by the old foundry building in Martinsburg. This creek provided power for the businesses in the foundry and others nearby for many decades.
The image was captured with a 2.5 second exposure at f/16.
The other local waterway was Town Creek in Shepherdstown, just above where it flows into the Potomac River. A wooden footbridge provides a handy spot to set up the camera and the tripod to capture the shot. The image was captured with a 3.2 second exposure. The aperture was not recorded because I used a manual focus lens but it was probably something like f/16 or f/22.