Mighty Susquehanna
And the dam that (tries to) control it

The upstream dam …

turns on and off throughout the day.

Looking upstream through the fog and snow to the Conowingo Dam

But it’s never enough to completely shut the river off. The Susquehanna Flats are wide. About a mile to be exact. This photo is taken about 2 miles downstream of the Conowingo Dam that was completed in 1928, coincidently the same year as the Tamiami Trai. So who would have ever thought: a thousand miles apart, the headwaters to Chesapeake Bay and the Everglades got cut off on the exact same year.

bobby angel

Ode to a river
Pretty Boy and the Gunpowder music video

To be honest I was miffed:

How could cartographers leave the Gunpowder out?

Words and music by Bobby Angel

My response was to right this song. Yes, the Susquehanna River is the Chesapeake Bay’s largest tributary, and the Potomac River is bigger too and also drains the Shenandoah Valley. But to look at a map of the drainages of the Chesapeake Bay and to leave the Gunpowder out downright irked me on too many levels to count. But what is a hydrologist to do? And who do I complain to? My philosophy: Never complain and never explain, and rather get down to the business at hand. And specifically, that means telling the story of a pretty special river that sadly people don’t know exists, or sorely misunderstand. The opening line to the song came to me while hiking the river trail just above Jerusalem Mills. I refined the lyrics in the following days in the loft overlooking a brook that feeds the river. But it wasn’t until returning to Florida that I finally put the final touches on the song, and in particularly the last two lines.

Where does this song rank in the Maryland song canon? Behind the Star Spangled Banner and Maryland My Maryland, I’m having trouble coming up with a third. That being the case, I’ll rank it 2nd since Maryland My Maryland is a knock off of Oh Tanenbaum.


Floodplain features
Working river returns to nature

Hiking the Gunpowder River …

is a study in floodplain dynamics.

Cross section of the Gunpowder River Valley

Not just a single or simple valley that the stream sometimes overtops, a hike along the trail is a living textbook on the many features and geomorphic processes in action. Rapids for example usually occur where larger rock outcrops are visible on the hillside. And it’s not just a single channel. Also periodically present are yazoo tributaries, oxbow lakes, backswamps made soggier by logjam pools and dry meander scars that the river once cut out. But maybe my favorite feature is the older terraces that form a stairstep from the modern-day floodplain to the adjacent hillside. Today, the terraces are home to very large trees. So they haven’t flooded for quite some time. But how long? Was it a feature from the higher flow rates experienced in the waning days of the last ice age? Or has upstream Pretty Boy and Loch Raven Dams reduced river flows below a point that water makes it up onto that second step?

Another feature I didn’t show was the many archaeological remnants from the pioneer days. They too leave me to wonder: Today, the corridor is a nature preserve, but for the original settlers, it was a working river that powered many a mill.


Chesapeake Bay Watershed
And how it compares to Lake O

How big is Chesapeake Bay …

Or more importantly, its watershed?

Map of the Chesapeake Bay Watershed

The Chesapeake Bay watershed comprises 64,000 square miles, encompasses six states including Maryland, Pennsylvania, Virginia, Delaware, New York, West Virginia and all of the District of Columbia. The land-to-water ratio of 14:1 is the largest of any coastal water body in the world. But how big is all that in Lake Okeechobee units? Excellent question!

Answer: The Chesapeake Bay Watershed is 88 times the size of Florida’s Lake Okeechobee and the bay itself is six times the size of Lake Okeechobee. I know what you’re thinking: That’s an unfair comparison, i.e. what happens when you throw in Lake Okeechobee’s upstream watershed (including the Kissimmee River Valley, Fisheating Creek, Lake Istokpoga and a few more)? Even then the Chesapeake is a lot bigger — 13 times bigger than Lake O and all its upstream watersheds.

I‘m not saying the Lake isn’t big, all I’m saying is it makes a good measuring cup.

Watersheds of south Florida

Valley in the plateau
The Piedmont Plateau to be exact

The Gunpowder River …

Isn’t a major tributary to the Chesapeake Bay.

Little Gunpowder River looking upstream

And on many maps you cannot see it named. That doesn’t make it any less of a vital water way to keeping the bay clean. It’s a bit of an untamed river. Farther north are the Pretty Boy and Loch Raven Reservoirs that supply water to downstream Baltimore. And back in the era when running rivers were a local power source, it had a mill or three along its length. But more or less those water works have washed away. It’s good to see the downstream two-thirds of the river running free.