Updated: ESD and Your Dock
Nothing fires up action in local government quite like having to take responsibility for a lack of adherence to safety standards that results in a death. After 3 deaths in 2012 due to faulty electrical wiring, both Osage Beach, Village of Four Seasons, and Lake Ozark have made changes in local ordinances regarding dock wiring. All docks must now conform to National Electrical Code standards and be inspected before Ameren will grant a new dock permit or when property ownership changes. Both the Osage Beach and Lake Ozark Fire Department Districts provide the inspection for a fee.
Electricity and water are always a tricky combination, and water soaked skin makes for a near perfect conductor, but proper design and installation of a dock's electrical system can mitigate the risk to acceptable levels. I encourage all property owners to have their dock wiring inspected and certified regardless of whether or not it is required and, if found deficient, have a certified electrician do the work. It is not enough to know basic wiring and common sense to wire up your dock anymore.
For instance, many docks have, and are now required to have, a shoreline over current protection (fuse, or circuit breaker) or disconnect device located on-shore to disconnect main power to the dock, but what is not commonly known is that this device must be within six feet of the ramp AND a minimum of 42" above the ramp walkway, or no lower than 665' elevation. Currently, it is very common to see dock disconnect junction boxes set only a few inches above the ground, although most are within 6' of the ramp. A thorough understanding of electrical bonding is also needed as all metal parts of a dock must now be connected to ground. There are commercial systems available designed to monitor for leakage current in the water, but these are NOT required, and unnecessary if the wiring is to code. The many requirements of the NEC are beyond most weekend-wire-nuts like me to know and implement properly, but there is no law in saying you have to have a licensed electrician do the work. Just don't complain when you have to pay to have it re-inspected several times to bring it to compliance or even start from scratch. Wiring is expensive and getting it wrong can be very costly.
Ameren does not provide inspections but they do provide some insight into what you can expect.
Dock Expanded Electrical Requirements (PDF) (2019 Note: This is an archival version from the date of this post. An updated version is available here).
As property owners we have a responsibility to our families, and our neighbors, to keep the lake as safe as possible for everyone.