Bridges over Fertile Water
Bridges over Fertile Water
The sounds of a rhythmic “bloop – bloop – bloop” resonate in the darkness. A sudden, explosive splash raises just about every hair on the back of my neck. I am not sitting watching a cheap horror movie; rather, I am fishing under a highway overpass.
Bass holding under bridges is not news to anglers. Many are familiar with their fertile ecosystems and fish-holding capabilities. However, I challenge those anglers to move away from the rip rap banks and describe in detail the bridge supporting structure beneath the water. Understanding bridge foundation types, angling applications, and seasonal patterns can be the key to selecting the most effective presentation for the structure-minded bass.
For starters, a foundation is a term used to describe all the structural components required to support a bridge deck. Foundations can be grouped into two basic classifications: spread footings and piles. As its root word insinuates, a footing resembles a “foot” placed upon the river or lake bottom. A pile, on the other hand, extends beyond the subsurface to a predetermined depth. Most anglers have seen both foundation types, whether it was consciously recognized or not. From the perspective of the bass, the various foundations represent a multitude of habitats.
There is More to a Bridge than Meets the Eye
Spread footings are one of the oldest bridge foundation types. The relative ease of construction has made these foundations commonplace in historic applications. There are a few distinctive characteristics to these supports. A large concrete “base plate” is constructed upon a stable subsurface. That plate is generally rectangular in shape, and can extend across the entire width of the bridge deck to support single or multiple piers. Since the spread footing is thick, current breaks are created at the bottom corners of the structure.
Conversely, bridge piles are relatively hydrodynamic in shape. They can be identified as a series of steel cylinders. Piles, however, may not be immediately visible above the water when a group is assembled to create a pier. From above, a pier may look like a single support to the bridge. While below, rows of piles bear the load of the structure. Bridge piles are commonly drilled or driven, and the cylinder is often used as a form for the poured concrete. While a single pile creates less turbulence than spread footings, multiple piles are required to carry the same loading. This provides additional locations for bass to reside.
Above: Common Bridge Foundation Types
Using Current to Your Advantage
Bridges over rivers and streams can simplify the search for bass. Identifying the current breaks, also known as eddies, within the system is the key to narrowing that quest. Look for breaks at the downstream side of the foundation. And, recognize that the size of that current break can vary depending upon depth. The flow of water along the bottom of a river is slowed due to the resistive drag against the bottom. Dropping a lure into the specific break can be challenging. Casting upstream and allowing the bait to find its way into the eddy is easier and will place the bait in the strike zone for the greatest amount of time. When bass are holding near the surface, use of a slow-sinking soft plastic jerkbait like a Gambler Super Stud presents an offering that the fish cannot refuse. Floating topwater poppers and walking baits can also be maneuvered into the desired areas.
The zone at the base of a bridge foundation can provide additional targets for the bass angler desiring to put more fish in the boat. The drop shot rig, popularized by national touring professionals, is a top choice for effectively presenting lures at the bottom. In this technique, line size plays a critical role. Lines that are too great in diameter will pull the lure out from the current break and away from the fish. To minimize the effect, selecting one with a smaller diameter is not a bad idea; the challenging process of landing a big fish on light line can only occur after it is enticed into a strike. As a second factor, increased drag that accompanies larger lines will make strikes more difficult to detect. Use of an ultra-sensitive, light-weight rod is paramount when attempting to maintain feel with a lure in current. Rogue Rods of White City, Oregon has three rods specifically tailored to the drop shot technique. The DS 693S is one spinning model that handles light line with ease. With small, featherweight Recoil line guides, it is one of the lightest and most sensitive drop shot rods on the market today. With the proper equipment, the drop shot can also be effective around bridges where current is not commonplace.
Above: Current – Foundation Effects
Not all bridges are constructed over rivers or streams. Many will cross over channels separating bays or additional lakes in a chain. Those geographic constrictions can have flow generated by factors other than gravity. Wind is the most recognizable. A body of water exposed to differential wind speeds creates “artificial” current. In those situations, bass can be much more aggressive than their current-acclimated counterparts when baitfish are caught off guard. With a spontaneous flow, easy meals are at hand for hungry bass. The temporary current can also occur in opposite directions within a relatively short period of time. When a storm approaches with strong winds, a tidal effect is created under the bridge as water surges from one area into the other, and subsequently recedes to a stable level after the event. In those circumstances, the movement is most prevalent at the top of the water. The wind provides the force which acts upon the top of the water column. Again, surface lures will be effective; however, alternative bottom techniques that cannot be utilized in rivers are also good choices. The new Gambler Giggy Head jig excels in chunk rock and light bite situations. Coupled with a semi-buoyant finesse lure, the jig will stand straight up when it comes into contact with the bottom. In addition, the unique lure keeper extending below the head is designed for easy weedless rigging and prevents rotational bait fouling during light pick-ups.
Above: The new Gambler Giggy Head
Other Bridge Fishing Nuances
Erosion. Aside from providing feeding zones for awaiting bass, current can indirectly create alternative targets for bridge fishermen. Foundation scour is created by the turbulence around a footing. The various wakes created between the foundation and water flow eventually erodes the bottom away from the bridge pier. Additional areas for fish to hold are created on both sides and even in front of the foundation as a result of scour.
Shade. Another factor not to overlook when fishing bridges is shade. The position of the sun in the horizon shades different areas around a foundation throughout the day. Bass will use the shade to their advantage in ambushing prey. The presence of shade, or lack thereof, can be used to further refine bridge patterns for the time of day.
Autumn. The fall season brings migration of both bait fish and bass. Migration routes through a lake chain or river system are often intersected by bridges. Bridge system habitats that may only support a few bass throughout the year can be fortified by migrating baitfish. This influx of supplementary forage will attract additional bass, and often in great numbers. In addition, the seasonal end of the aquatic vegetation life cycle encourages bass to search for temporary habitat prior to wintering. Chunking spinnerbaits and minnow–mimicking lures are a perfect choice around bridges in the fall.
Rip Rap. Finally, rip rap along the base of a foundation is often overlooked in lieu of the obvious rocky banks leading to the bridge deck itself. Rip Rap is often placed to provide additional protection against erosion at the foundation base. The placement of foundation rock is most common for older bridges and those structures that cross natural flowages of water. Diving Crankbaits ricocheted off rip rap can elicit reaction strikes where other techniques cannot. Carolina Rigged creature baits and Ugly Otters retrieved upstream can be slid over and presented tight to the rocks.
Too Simple for Some
The next time you are on the water, don’t overlook bridges. As simple as the structures may appear to be from above, focusing on the structure beneath will give you a decisive advantage when selecting the most effective presentation. For more information on the new Gambler Giggy Head, visit Gambler’s website: www.Gambler-Bang.com. For information on Rogue Rod’s Drop Shot Rod, visit: www.RogueRods.com.