Dock Building in Jefferson City, TN

For anything on a TVA reservoir, yes for new construction and for changes, and often not for a genuine like-for-like repair. TVA administers this under Section 26a and it covers building, altering or replacing a structure on its reservoirs. It is separate from anything the county or city requires. Because the boundary sits exactly where repair starts becoming modification, it is worth confirming before work begins rather than afterwards.

The reservoir decides it more than preference does. TVA draws its lakes down for winter flood storage and the size of that swing varies enormously — Melton Hill is held nearly steady, Fort Loudoun and Tellico move within a fairly narrow band, and the storage reservoirs like Norris and Douglas move a great deal. A fixed dock is simple and stable where the range is modest. Where the water moves a long way, a fixed dock is unusable for part of the year and floating is the answer.

Because it was built to summer pool on a reservoir that gets drawn down for flood storage. It is one of the most common problems on these lakes and it is a design issue rather than a fault in the construction. The usual fixes are rebuilding the lower access section for the full range, or converting to a floating arrangement so the dock follows the water.

Longer than most people expect when the frame is right and the hardware suits permanent immersion, and much less when either is wrong. What shortens it is the wet-dry cycle these reservoirs impose: a structure that is submerged part of the year and dry the rest finds every untreated cut, unsealed fastener hole and thin galvanising. Frame and fixings decide dock life far more than the decking does.

It depends on size, whether it is fixed or floating, water depth, how difficult the shoreline is to reach, and whether a lift or a roof is involved. The permit process also affects what is buildable in the first place. Rather than publish a range that would not survive contact with your shoreline, the useful step is a quote against the actual site.

On a schedule rather than when they look bad. Cables corrode from the inside and at the points you cannot see — inside the drum and over the sheaves — so a cable can appear serviceable while it has already lost much of its strength. Any cable showing broken strands, rust staining or flat spots gets replaced immediately. Cable failure means losing support for the boat, so it is treated as a safety item.

Frequently more easily, because the reservoirs are drawn down and structures are more accessible with the water lower. The trade-offs are a shorter working day and colder conditions. Which season suits depends on your lake and on what the work involves — winter drawdown is genuinely an advantage for some repairs.

Mainly how far they move. Melton Hill is held very steady, which is why it is used for rowing. Fort Loudoun and Tellico are navigation pools kept within a fairly narrow band. Norris, Douglas and Cherokee are storage reservoirs and swing a long way seasonally. That difference drives dock type, access design and what a permit will allow, so a design that works on one lake often does not transfer to another.