There are a number of river gauges along the South Fork of the Shenandoah River which give the river level in feet for that location, but each gauge is independent of the others in its reading and rate of change, which makes it difficult to compare the readings of various gauges by using river level in feet as a measure.  A better method is to measure flow, cubic feet per second, with the acronym “cfs”.  For example:  today the river level for Luray is 2.29 feet with 523 cfs, and the river level for Front Royal (located 43 miles downstream from Luray) is 1.53 feet with 665 cfs (more flow, but a lower gauge reading in feet).  The river gauges are maintained by the U.S. Geological Survey and the information for each site is available to the public through a number of websites such as “River Watch” and “Flood Watch” or best of all “waterdata.usgs.gov“.

After a significant rain event we can follow the surge in flow by monitoring the river gauges up stream of our location and predict when and how high the river will get.  Typically a rain event in our upper watershed (which can be 100 miles or more up river) will take a several days to reach us, but a big, local rain event can be upon us in hours, so it can get tricky.  For us, the river gauge system is a vital tool in river safety and we use it constantly.  Back in the day, before the internet, we used to call a toll free number in Maryland and listen to a long recording giving the gauge readings for the region (and the line was often busy).

So for today, the flow of the South Fork of the Shenandoah River at Luray is 523 cfs.   There are 8 gallons of water in 1 cubic foot, so the flow is currently 4,184 gallons per second and by extension 361,497,000 gallons per day.  That seems like a lot of water, but we place the river level in our “Low” range for today.  The highest recorded river level was about 27 feet at Luray during the flood of 1870 when the Valley was pretty much denuded of trees from the civil war and the then flourishing local iron industry’s insatiable thirst for charcoal.  The lowest was during the great drought of 1930 when the river was a sea of rocks with little pools of water in-between (I’ve seen photos).  

What did the fish say when it swam into the wall?  Dam!  Yes, there are a number of surviving low production power dams along the South Fork of the Shenandoah River at 3 locations, in the town of Shenandoah, near the village of Newport, and near Luray.  Built in the early 20th century these dams are 18 to 20 feet in height and are constant generation dams that are required to maintain a veil of water flowing over the top so the natural flow of the river is maintained.  Both the Shenandoah and Newport dams have portage paths around them, but the Luray dam does not (due to property rights restraints).  Fortunately, none of these dams are located in our operational area.

These dams do not generate a whole lot of electricity, but there they are, and as long as they are productive and are maintained by the power companies that license them, there is no reason to alter the status quo.  Some day their usefulness will end, and a decision will have to be made.  Dam removal, returning the natural flow to the river would be the obvious choice, but would cost at least several million dollars for each dam.  In fact, the diversion dam at Lynnwood was destroyed by the flood of 1942, and the shattered concrete with imbedded rebar was a life threatening hazard to paddlers until removal of the remains of the dam was undertaken in the early years of the 21st century.