It rained steadily through the later half of last week. Although the rain was not heavy enough to cause flash flooding in the neighborhood, it rained long enough to cause a record or two to be broken in terms of the volume of rainfall we received.
There had been warnings in the weather reports about possible flooding on the river over the weekend because of the rain. It was an unintended invitation for me to check out the conditions at Dam 4 on the Potomac on Sunday. Although the rain had stopped by that time, its impact on the flow of water on the river was still in its early stages.
The water was nearly up to the level of the road as we approached the parking area for Dam 4. The entire trail was under water downstream of Dam 4. In the picture below, you can see the trail vanish into the water as it descends from the level of the dam.
Instead of gently flowing down the side of the dam as it usually does, the water was pouring out with full force well beyond wall of the dam – into a chaotic churning foam of brown whitewater.
All kinds of flotsam and jetsam, including massive tree trunks, were being carried over the top of the dam, only to be caught in a debris field at the bottom of the dam.At one point I even noticed a huge tree truck caught in a upright configuration above the swirling waters. It held that position for an moment or two, somehow magically kept balanced vertically by the chaotic forces of the swirling waters at its base, before finally disappearing into the downstream flow. There was the steady roar of the angry waters of the river in the background.
The road upstream of the dam, in the direction of the parking lot at Big Slackwater, was closed because of the conditions, but the trail was still open. So we took the opportunity to walk towards Big Slackwater to see what the conditions were like there. On one side of the dry trail was the swiftly flowing river, now just a couple of feet below the level of the trail because of its flooded state,and on the other side, well below us, was the canal – usually dry but now full of water because of the rainfall.
The difference in heights of the river and the canal in this section is because they are fully separated. If not, there would have been water close to where we were walking on both sides of the trail, in which case the trail would probably have been closed. As things stood, I still had a nagging concern about the the river possibly cresting above the trail while we were on it.The trail itself looked like it had been recently repaved.
The trail was marked as being closed beyond this point, but we walked a couple of hundred feet more along the pathway to the inlet lock from the river. No water enters from the river at this point because the lock is now cemented shut.
Just beyond the inlet lock we could see the trail disappearing into the water as it descended to the level of the river.It was clear that we would not be able to continue our travels further upstream. The trail at Big Slackwater was clearly not passable. We had to return to Dam 4.
The parking lot at Dam 4 had been empty when we first arrived, but there were many more vehicles there by this time. Some people were fishing at the stop lock and others were watching the water flowing over the dam.
Since we were still interested in seeing the impact of the high water on the river, and since we had not walked much at the point, we decided to drive to Great Falls, closer to home, to take another look at the river.
We encountered the usual weekend park traffic when we arrived later in the morning at Great Falls. The parking lot was about half-full. The walkway to Olmsted Island, from which vantage point you can see the actual Great Falls, was closed because of the level of the water. So was the Billy Goat Trail over Mather Gorge.
But one did not have to leave the towpath itself to see the impact of the flooding. Water was pouring over Dam 2 just upstream of The Tavern at Great Falls,and all of the rocks that one would normally see in the path of the river next to the towpath in the area just downstream of the tavern were completely under water.
The section of Mather Gorge next to the towpath was full. This is how the area looked under normal conditions a few months ago.
We did continue our walk along the towpath towards the far end of Widewater, to the place where the Billy Goat Trail ends. Being separated from the river, the water in this section of the canal was at its normal level. Everything was calm.You would have had no suspicion that the river was in its full fury just close by – just a few hundred yards away on the other side of the trail.
We encountered many people on the trail, both on foot and on bikes, during this part of the morning walk. Many people live in this area of Montgomery County. It must have felt good for them to be able to get outside after having been cooped up indoors because of the rain.
I will end with a final note that the river does usually return to its normal levels very soon after an episode like this.