Knowing how to fish a warm-water discharge stream greatly increases the probability of a successful fishing trip, which ceretainly applies to fishing at the Calvert Cliffs Nuclear Power Plant (CCNPP). With this in mind, years ago I went on a pre-season catch-and-release guided trip with Walleye Pete before taking my own boat into the discharge stream. I wanted to learn bottom structure, local operating conditions, and site-specific fishing techniques. My observation was that turbulence there could tip a small boat and pull a person under. I also observed that the extreme outflow created a jet-like effect which produced suction that drew in surrounding water and baitfish, which are delivered to waiting predators. Learning this site and how to fish it under various operating conditions was going to take many trips.
This hotspot eats tackle, especially from those who don’t know how to fish it—as I certainly learned during that first trip, and subsequent trips, with Pete. Of course, you could just go there and toss jigs into the turbulence and sometimes catch a fish. But knowledge of the structure configuration and jigging mechanics in high-current flow are fundamental to fishing it effectively. My recommendation based on personal experience: invest in guided trips so that you can focus on learning the site and building effective hands-on skills to fish it. That said, the following observations will give you a jump start.
Calver Cliffs Warm Water Discharge Configuration
The nuclear plant’s water intake and discharge are regulated. Cold water intake occurs inside the charted restricted area shown above. The cooling water is drawn in from an uncharted dredged intake channel that extends out to the northeast directly in front of the plant and out to deeper water. Channel depth isn’t charted and charted contours often aren’t correct here. The channel is very wide and current velocity is relatively slow, thereby minimizing entrapment of fish and baitfish at the intake control structure. Cold water is more dense than warmer surface water, so the current flow would be more along the bottom than near the surface. The channel’s location also puts it in position to receive bait carried north on an incoming tidal current.
The warmwater discharge occurs from a subsurface concrete structure off the northeast corner of the power plant shoreside complex. The structure consists of four concrete conduits. Least depth at the top of the structure is about six feet. The base is at a depth of about 15’. There’s a narrow scour trench at each corner that drops down two to three feet. The bottom in front of the discharge is about 17’ down and quickly slopes down to about 20’ of depth 100’ in front of the structure, and then slopes down to a depth of 25’ about 150 yards out.
The discharge feeds into a canal that is oriented from the outlet towards the northeast paralleling edge, with a shoal along its northern side. The outlet structure is protected from scour by huge rocks directly in front and by additional rocks which line and stabilize the canal bottom.
Hydrographics at Calvert Cliffs
The discharge rate is nominally 1.2 million gallons per minute per each of the two generating units, or 2.4 million gallons per minute when both are generating at full capacity. The discharge volume and strength of the current varies depending on whether or not the plant is generating electricity at full capacity. So, how do baitfish end up in front of the outlet with all this water rushing out? The fluid dynamics that enable this are incredibly complex. All the formulas included in hydrodynamic modeling, theoretical studies, and assessments of this site and other warm water discharges look like just a bunch of squiggles on paper to me. But sorting through the details led to some basic insights.
The discharge stream is a three-dimensional thermal plume characterized as a turbulent jet with a stratified flow and a semi-free boundary. The plume shoots up from the openings in the outlet, as the excavated canal provides a semi-bounded pathway that steers water flow towards the northeast, thereby providing separation between the outflow and the intake feeder channel to the south. Water temperature can be no greater than 12 degrees Fahrenheit warmer than ambient Bay water. Stratification occurs with the warm jet on top and a cold-water wedge underneath, which slopes up towards the bottom of the outlet.
The turbulent jet plume produced by this dynamic discharge has both momentum and rises due to being warmer than the surrounding water. The latter reduces or eliminates vertical mixing between the thermal plume and the underlying water close to the outlet, where the dominant force is the momentum of the discharge. This produces the turbulent surface flow we see shooting up and out in front of the outlet.
The net effect is stratification in the water column with the plume on top and a cold-water wedge underneath, with the thicker part of the wedge directly in front of the outlet. However, turbulence can at times reach all the way to the bottom, especially when rough surface conditions interact with the discharge stream.
Striped bass forage and feed where current delivers or disorients baitfish. So, bait interaction with prevailing current is an important consideration. Fishfinders often show baitfish in front of the outlet and within the canal below the plume turbulence. And right in front of the outlet on the bottom is often where large striped bass stage in ambush. Note that they are not wasting energy fighting the jet stream—they’re under it. That’s why keeping your lures in close contact with the bottom is so important.
My observation is that the discharge creates suction immediately off the face of the outlet at its northeastern and southeastern corners which draws in cooler water from outside the plume. The draw on the north side seems stronger, especially when tidal currents are ebbing. On a calm day just after the flood starts, I’ve also observed incoming current pushing water up against the southwestern edge of the discharge current. Baitfish caught up in this are drawn into the discharge stream, which concentrates and disorients them, and then delivers them to or above stripers waiting along the bottom for a meal. Baitfish also visit the heavily biofouled rocks coming in from the sides of the canal under the stratified warm water layer.
Conditions are dynamic and continually changing, so fish can be found almost anywhere under and sometimes in the moving current. Look for speckled trout farther out in the stream under the turbulence and sometimes closer to the edges of moving current.
Fishing the CCNPP
Regardless of water flow mechanics, the basic fishing technique used here most often involves jigging with lead-head jigs tipped with plastics such as BKDs or paddletails. Use a moderately heavy leader to mitigate the abrasion of rubbing against rocks and as little weight as necessary to touch bottom in the current flow (usually an ounce, sometimes a bit more). Cast upstream to allow your jig to fall to the bottom, otherwise it will “float” in the current as your line gets stretched out downstream. Anglers should start snap-jigging immediately the instant it touches bottom and don’t let it rest or drag, or it will most likely snag.
Where to start casting depends on conditions and your best guess. Some anglers drive the boat into the discharge stream, starting as close as practical to the upwelling on the Bay side of the outlet, and ride the current out towards the east. In this case they may drop the jigs as soon as the boat settles and jig vertically. Sometimes the current will carry the boat in the stream all the way out to where it disperses. Other times the current will spit the boat out to either side. But note that sometimes fish are farther out in the stream, especially schoolie stripers and speckled trout. The way to figure this out is to ride the current jigging your way out until you find the prevailing sweet spot.
Another way to fish the site is to either drift or anchor on either side of the outfall and cast in. Jigs should be worked the same way, snapped along in close proximity to the bottom. This works, although anchoring limits the area that can be covered plus finding bottom once the jig is carried downstream can be next to impossible. Some anglers will set up a round-robin of sorts when anchoring, with each individual casting upstream then moving to the downstream side of the boat once the jig hits bottom, so the next angler can move in for their upstream cast.
Anchoring adjacent to the outfall when other boats are fishing the stream blocks their access and can be contentious. When this happens, it’s not uncommon for other boats to push into the stream from behind the outfall directly over the top and split the distance between the anchored boats. Boats will also push in from the side fairly close to the anchored boats and drop lines once the current grabs the boat and starts carrying it downstream away from the blocking boats.
Sometimes Calvert Cliffs provides fishing conditions suitable for smaller boats when the main stem Bay is too rough for an enjoyable fishing experience. Other times a breeze running counter to the outflow can cause large, dangerous standing waves. Even when it’s calm there is always turbulence and undercurrents. A person who falls overboard can be sucked down, tumbled around, and held underwater. Don’t take a chance here. My recommendation is to always wear a Personal Flotation Device (PFD), even when on a charter boat or on a guide trip since they don’t have special exemption from Murphy’s Law.
Courtesy at Calvert Cliffs
Ever since the 1970s the CCNPP has been an awesome hotspot—and a source of controversy and angst among some anglers. Remember, everyone is out there to have fun, nobody “owns” any fishing spot including this one, and every angler has equal claim to be there. If you fish here you have to expect there to be a crowd, especially on weekends. That said, it’s always best to be considerate:
- When deciding whether to anchor or drift consider how many people you might inconvenience in one way or the other.
- Stealth is important, and noise can shut off the bite. Yelling, stomping on the deck, slamming hatches, and shifting into and out of gear are just a few of the things that do the trick. See Spooking Fish with Your Boat to learn more about how we sometimes scare the fish off.
- Staying out of the current and casting into it rather than drifting through it will minimize the amount of noise created directly over the fish.
- Try to stay outside of casting distance of other boats, but remember that different boats drift at different speeds and it’s often impossible to maintain a measured distance. If you feel someone’s getting too close recognize that they may have positioned their boat respectfully, but simply got pushed in an unexpected manner by the current or wind.
- When motoring up to the outflow after a drift, circle wide and stay at pre-planing speeds so you don’t accidentally wake all the other anglers.
As well as being a regular contributor to FishTalk, Wayne Young is the author of multiple books detailing wrecks and fishing reefs in the Chesapeake Bay, Delaware Bay, and beyond. All are available at Amazon.com, and you can find his Facebook page at “Chesapeake Bay Fishing Reefs.”