User:Prioryman/List of reaches on the tidal Thames

The tidal section or Tideway of the River Thames in England is divided into a number of reaches and sections (a reach being that part of a river which stretches between two bends or as far as the eye can see). There are 27 reaches in all, divided between the three sections of the Tideway - the Upper, Middle and Lower Thames.

This page lists the reaches between the Thames Estuary and Teddington Lock, the highest point of the tidal Thames. They are listed in order from downstream to upstream, as would be encountered by a vessel entering the Thames from the North Sea. All distances are measured from London Bridge, a total distance of 50 mi downstream to the demarcation line that is treated as the start of the Thames Estuary and 50 mi upstream from the bridge to Teddington Lock.

The bridge is treated as the key dividing line between the downstream and upstream sections of the Tideway, as its arches mean that larger vessels cannot pass upstream. The lock marks another major dividing line, as neither the tide nor vessels wider than the lock can reach further upstream. The Port of London Authority's remit runs from the demarcation line in the Estuary to Teddington Lock, while the non-tidal river further upstream is controlled by the River Thames Conservators and is not in the scope of this page.

Apart from their significance for navigation - the beginning and end of each reach corresponds to a bend in the river - the reaches were also important for facilitating the passage of waterborne traffic on the Thames prior to the advent of motorised vessels. The bends cause the river to slow down, reducing the strength of the currents and creating eddies that skilled watermen could navigate.

Lower Thames
The Lower Thames is the section of the river downstream from Erith, where it gradually widens into the Thames Estuary and joins the North Sea. It runs for a distance of about 33.5 mi, terminating at the seaward limit of the Port of London Authority. This is demarcated by a line drawn on a bearing of 166° from Haven Point on the Kent coast to Havengore Creek on the Essex coast, a distance of 10 statute miles, which marks the start of the tidal Thames's reaches. The reaches in this section of the Thames are:

Middle Thames
The Middle Thames stretches from Erith Reach to London Bridge, a distance of 16 miles. The reaches in this section are:

Upper Thames
The Upper Thames consists of the section of the river from London Bridge to Teddington Lock, the highest point of the tidal Thames. There are eleven reaches in this part of the river.