Eliminate access to feeding sites and other areas.  This can be accomplished with fencing, which may be expensive or impractical depending on the size of the pond.  A sturdy, 4-foot-high fence constructed with 3-inch wire mesh is sufficient.  Bury the bottom edge 6 inches in the ground or use a wire apron on the outside of the fence to keep otters from going underneath the fence.

Alternatively, when practical, a properly maintained high tensile electric fence can be effective.  At least four strands, placed at 4- to 5-inch intervals, should be kept tight and clear of any weeds that could ground the charge.  The bottom wire should be low to the ground and the spacing of the wires should be close enough so that otters can’t get under or through without getting shocked.

River otters will occasionally den in the inflow or outflow pipes of a pond.  Seal the ends with fencing or flap gates that allow water to continue to flow through while excluding the otters.

Adapted from “Living with Wildlife in the Pacific Northwest” (see http://wdfw.wa.gov/wlm/living.htm) Written by: Russell Link, Wildlife Biologist, Design and layout: Peggy Ushakoff, ITAS2 Illustrations: As credited Copyright 2005 by the Washington Department of Fish and Wildlife