My dictionary defines riprap as "rocky material placed along shorelines, bridge foundations, steep slopes and other shoreline structures to protect from scour and erosion."
I'd go a step further and describe it as "one of the most outstanding yet often overlooked places to catch channel catfish in a river or lake." Riprap attracts and holds large numbers of catfish more consistently than most types of shoreline cover. If we put a dozen people on a strange lake and told them each to fish a different type of structure for a day, I'd bet my last dollar on the angler who picked riprap. Targeting the rocks is a strategy that produces channel cats year-round.
Riprap is found on most manmade lakes and navigable rivers, and everywhere it exists it is very attractive to catfish. One reason is because riprap provides a home for Mr. Whiskers' primary food supplies. Algae grow on the submerged stones, which attracts shad and minnows. Catfish arrive to eat the baitfish.
Every 10-year-old kid who lives near a body of water knows that crayfish—a favored forage of catfish—thrive under rocks, including riprap. Often, these rock walls are the only decent crayfish habitat in an entire lake, and catfish will stack up nearby to feed on the crustaceans. I’ve caught riprap cats with as many as two dozen crayfish in their stomachs.
The rocks also provide good, basic habitat structure. There is cover, depth, shade and protection. During summer, channel cats spawn in the deeper holes between rocks. Females lay their eggs and leave, and males stay near to guard the nests until the eggs hatch and the fry can fend for themselves.
Riprap also tends to be extensive, typically covering several miles of shoreline. If you fail to find fish concentrated in one spot, you can usually fish enough riprap on a river or lake bank to catch a limit.
When fishing river riprap for channel catfish, begin near the very ends of the rocks on dikes that run perpendicular to shore. If the catfish aren't there, gradually work your way past other riprapped areas. Concentrate your attention on unusual features that distinguish smaller sections of the rock walls from their surroundings. Sometimes a tree that’s been washed up is enough to attract catfish. Other times, a difference in the rocks does the trick—washouts and places where big boulders transition to smaller rocks. Points, cuts, pipes and culverts all create something different and might attract schools of catfish.
As you're checking riprap for these peculiarities, also look for unusual bottom features with a fishfinder. Alert anglers watch closely for features like a creek channel that borders a wall, submerged humps, pits, brush, a submerged roadbed or some other nuance that could concentrate fish on structure that might extend for hundreds of yards.
These rules about fishing the ends of the rocks first and locating unusual features apply to riprap on lakes, too, and for the same general reasons. Currents and wind-pushed waves washing over the end of a riprapped dike create an eddy or calm-water zone around the back side of those rocks and, at the same time, carry food downstream. This is not the case where waves wash straight into the riprap.
Although cats don’t necessarily hold in these slack-water eddies, they might swim in and out of them, moving over the end of the rocks in the process. If you’ve ever observed a school of shad or other baitfish swimming along the rocks, you know they stay in schools that are forever moving. They move up and down the rock walls and around the ends, and catfish often follow.
Bridge riprap can be especially important in lakes. Catfish are funneled into the narrow section of water where a bridge crosses and they stay to feast on baitfish and other forage animals. Most fish hold out of current in places where they can rush out to eat groceries washing past.
When fishing bridge riprap, the four corners formed where the riprap bank gives way to the bridge superstructure are always worth a few casts, regardless of other structure present. These corners form semi-points that often hold several catfish. The downcurrent points are best, as these are ideal ambush spots for cats. Cast into the current from a boat stationed on the bridge’s downcurrent or downwind side. This allows your bait to move downcurrent in a natural manner.
Under tough windy or post-frontal conditions, bridge riprap can produce catfish when other areas prove fruitless. The feeding habits of bridge-oriented cats seem to be less affected by these conditions than those of other catfish populations.
During windy weather, bridge riprap really excels due to the funnel effect discussed above. Wind increases the flow of water and food through the area. Resident catfish react instinctively and line up to feed on baitfish blown into the rock walls. Also, as the wind throws choppy water on the rocky bank, crayfish are stirred up and become easy pickings for feeding cats. Unless there are safety risks, the riprap angler welcomes a good wind, as do catfish, especially during the hot summer months.
Because bridge-oriented catfish are primarily deep-water residents that move occasionally into the food-filled shallows, weather fronts tend to have less of an adverse effect on them than other catfish. If the creek or river channel beneath the bridge is fairly deep, catfish can avoid much of the trauma associated with a strong front.
Catfish also find extensive areas of shade around bridge pilings and beneath the superstructure itself that provide relief from harsh, post-frontal sunlight. Catfish anglers fishing bridge riprap unexposed to harsh light can often avoid many difficulties associated with post-front doldrums.
Every cat fan has his favorite baits, but some work decidedly better than others when fishing riprap. Baitfish and crayfish are at home in this rocky environment, so naturally shad, minnows and crayfish should rank high among catfish anglers’ top choices.
A three-way rig with the weight and hook on separate lines will save a lot of time re-rigging. Weights often fall in crevices between rocks, sometimes lodging and causing hangups. Rig a weight line that’s of lesser breaking strength than your main line and hook line, and all you’ll lose to a hangup is lead.
Catalpa worms are another popular bait. They're easy to acquire in much of the Midwest, are attractive to catfish and they stay on the hook even in swift water. Nightcrawlers are always good; however, when stream fishing, you’re often apt to catch more drum on them than catfish. Dough baits don’t usually hold to hooks well in current. Sponge baits and dip baits are fantastic for all types of riprap catfishing, though.
Don’t overlook artificials for catching some jumbo channel cats, either. Many baitfish- and crayfish-imitating crankbaits will coax bites from cats when bounced through the rocks. The deep-diving models work better, as the longer bill helps keep the line from snagging. Riprap catfish will also hit a variety of jigs and spinners.
Riprap offers all of the things that channel cats need for living high on the hog, so it's little wonder that you can find so many cats on the rocks. What is surprising is the number of anglers who tend to overlook riprap. If you’re one who usually cruises past this great structure, stop next time, and take a second look at those rocky riprap walls. They could save you from a lot of otherwise fishless days.