Do not build ledges or stepping-stones along your pond during pond installation. Ledges and steps allow the raccoon to easily fish out koi from the pond. Include hiding places deep in the water to protect your fish. Create caves from flowerpots or pipes for the fish to hide in when a raccoon enters the pond water.
Scare and Repel
Many pond scarecrows and electronic devices are available to scare away intruder animals from ponds. These machines are motion-activated. Place them in an open area of the pond unobstructed by trees or other pond plants. The scarecrow will make noise, flash light or shoot water at a raccoon, and scare it away before it catches a fish or destroys your garden. Other moving objects, such as a windmill, may also scare away raccoons. However, after a few days, raccoons may realize the electronic scarecrow or moving object poses no actual threat and return to the pond to dine on your fish. Commercial pond-safe raccoon repellents are available, but according to the University of California Statewide Integrated Pest Management Program, no repellents have been effective at keeping raccoons away.
A regular backyard fence cannot keep raccoons away. Raccoons will quickly learn to scale the fence, or just dig underneath the fence. They will even rip holes in fences or take apart boards to reach your pond. Installing an electric fence is the most effective way to protect your pond and keep raccoons out. Install an electric fence with two wires 6 and 12 inches above the ground, or run electrified wire along the fence you already have installed. Consult a professional before installing an electric fence yourself.
Protect your pond by trapping and removing the local raccoons. Raccoons are trapped in baited cages. Lure the raccoons into the trap by creating a trail of food that leads into the trap. Keep in mind that you may trap other animals, such as cats and dogs. Also note that depending on your local or state laws, the raccoon may be euthanized or relocated. Call animal control if you caught a raccoon in your trap, or consult a professional if you have no experience trapping raccoons.