Update on the Potomac

We returned to Algonkian Park when the Potomac River was running bank-to-bank and about to spill onto its flood plain (Fig. 1).

The water level is several feet higher than on our last visit, and is expected to crest in two days. Unfortunately, I won’t be here to document that event, but I expect the water to be covering the picnic table placed on the active floodplain in Fig. 1. Low areas were inundated (Fig. 2).

Unfortunately, I didn’t take a photo of several large logs resting on the grassy floodplain, deposited by a previous high-water event. Nevertheless, a log can be seen lodged against the bank in Fig. 1, and many more were racing by at 3 feet/second, some more than twenty feet long.

Because of its dynamic height and flow strength, the Potomac is constantly switching from eroding its banks to depositing fine sediment and organic matter on its floodplain. Still, it is downcutting into previous river deposits and spring floods are nothing more than a temporary anomaly in the inexorable transport of sediment from the Blue Ridge Mountains to Chesapeake Bay.