By Dr. Peter Brookes
I recently noticed that I’d been coming across a good number of articles on the dropping of some old dam or another on a Virginia and or other out-of-state waterway. I guess that’s what I get for subscribing to Dam Destruction Daily….
Read about the removal of a dam in Buckingham County in Tear Down That Dam: Reconnecting a Piedmont Stream.
But seriously: What’s all this dam(n) demolition about?
I’m no hydrologist, but as I understand it, dams have had—and can still play—an important role in water supply, flood control, hydroelectric power generation, recreation, conservation, manufacturing, navigation, and farming, among other purposes. But dams can also have a negative effect on fisheries and fishing.
It turns out that the removal of once-useful, but no longer purposeful, artificial barriers on Virginia’s waters can also bring a bevy of benefits, including—perhaps most importantly to DWR’s readers—better fishing.
I thought that might get your attention….
Indeed, according to experts at the Virginia Department of Wildlife Resources (DWR), such as DWR’s Fish Passage Coordinator Alan Weaver, and at DWR’s partner organizations in project likes Trout Unlimited, and American Climate Partners (ACP), here’s what a successful dam removal project can do for fisheries and fish:
Improve fish habitat: Restoring the natural flow of a dammed waterway increases the opportunity for fish in the system to move more freely up and down the waterway as needed, improving their overall viability. Reducing barriers to water flow and fish movement allows our finned friends to find better-suited holding areas in the waterway for protection, spawning, and refuge during low water periods, such as what parts of Virginia experienced last year. It can also offer better forage opportunities that might otherwise be denied due to the presence of a dam across all or part of a waterway.
Reducing limitations on water flow and fish movement also connects isolated fish populations, promoting genetic exchange and healthier fish stocks. Dam removal can eliminate water stagnation, improving water oxygen levels, water temperature profiles, overall water quality–and, subsequently, fish health.
Of course, these improvements can also increase the water’s biodiversity (insect and other aquatic life), fish recruitment (young fish entering the population) and, subsequently, fish population robustness (numbers). More fish for catching? Yes, please!
Removing dams is beneficial for not only the aquatic wildlife in the waterbody, but also for anglers and other outdoor enthusiasts. Photo by Meghan Marchetti/DWR
Expand fish movement/migration: Another benefit of removing a dam (once it’s been deemed no longer necessary through detailed study and thoughtful consideration) is the expansion of the movement/migration of fish species beyond their current restricted ranges and back to their historical habitats.
For instance, the dam dismantling on tidal rivers could expand the current range of anadromous fish species, such as Virginia favorites striped bass and hickory and American shad, that leave the saltwater for freshwater to spawn every year.
As we know, shad and stripers are facing challenges in the Chesapeake Bay, where they spend part of their life cycles. More good spawning habitat in Virginia waters could improve their overall numbers, benefitting anglers both on Atlantic Ocean, the Bay, and on Virginia’s tidal waters.
An example of this dam destruction work is a project to remove the 88-year-old Rapidan Mill dam on the Rapidan River in Rapidan, Virginia, which is now considered obsolete as a hydro-mechanical/hydropower facility. As you may know, the Rapidan River’s headwaters begin in Shenandoah National Park; many anglers, especially fly anglers, know the Rapidan River for its fabulous native brook trout fishing near the park.
But the river continues flowing eastward and joins the bigger Rappahannock River west of Fredericksburg. The tidal “Rapp” is a major spawning ground for migrating stripers and shad—and a prized fishing spot for them.
A Rappahannock River hickory shad. Photo by Dr. Peter Brookes
According to the ACP’s Rapidan Institute, which is working on the project with DWR and other organizations such as the National Oceanic and Atmospheric Administration:
…Removing the [Rapidan Mill] dam would open more than 500 miles—and as many as 1,000 miles—of habitat for American shad, river herring and other migratory fish…The 11-foot high, 12-foot-deep and 200-foot wide concrete Rapidan Mill dam blocks migrating shad, river herring, striped bass, eels and other fish from native spawning and rearing grounds upstream.
It’s hard to fathom (pun intended) that stripers and shad would venture that far inland, but it’s (historically) true. The removal of this dam quite simply means more miles of waterway and places to fish for our beloved shad and stripers.
Create recreational opportunities: Other than the preceding benefits to fish and fisheries, the dam demolition can open up the waterway to the unimpeded movement of fishing and other watercraft such as rafts, drift boats, canoes, and or kayaks.
This benefit can potentially mean longer floats for anglers and boaters. No portage around dams—if that’s even possible in some cases due to watercraft size or other limitations—to continue fishing or boating would be necessary, improving boaters’ safety while respecting private, riparian landowners.
Of course, it’s not just fish that dam removal helps; improving the natural movement of rivers, including nutrient flows, benefits the entire food web, including insects, birds, and other mammals that depend on the river ecosystem for life.
As you would expect, removing all dams doesn’t make sense due to the current utility of some of them. And, quite frankly, not everyone wants to see dams come down. Old dams can be valued for aesthetic, emotional, and or historical reasons, among others. That’s completely understandable.
For more information, DWR has an interesting landing page on its Fish Passage Program; it includes some history, scientific background, and a catalogue of completed and potential fish passage projects in Virginia.
Dam destruction can reconnect rivers, revitalize fluvial ecosystems, and create more vibrant fisheries. For the fish, these changes can result in better habitat and healthier and more robust fish populations and genetics.
But all that fancy fisheries shoptalk aside, for the Virginia angler, dropping disused dams quite simply means expanded opportunities for better fishing in the Old Dominion’s coastal, tidal, and inland waters.
Dr. Peter Brookes is a Virginia-based, award-winning outdoor writer.