Historically, because of its commercial nature, the tidal Trent is not closed because of “flood” or “fast stream” conditions by the navigation authorities responsible for it. Indeed, extra bank markers were put in place to help commercial skippers navigate between submerged river banks on the more powerful barges of years gone by.
Over the years, despite warnings about high “fresh” levels in the river from lock keepers, inland craft skippers have on occasion taken to the river at low tide to head upstream, only to find they gain no benefit from their anticipated flood tide, and they make painfully slow progress against the strong river flow as the water level raises disturbingly above its banks making navigation difficult to those inexperienced on the river.
Unfortunately, the type of simple “Red/Yellow /Green” flood gauge that CRT traditionally place on the bottom of locks going into rivers, obviously won’t work on a tidal river which can routinely go up and down several metres every 12 hours – and to date, CRT hasn’t been able to adapt their online “Fast Stream Warning System” to this tidal section of the river despite it being used to give warnings in two areas of the upper reaches of the river.
Therefore this simple, (but believed to be unique) “flood gauge” has been positioned on each of the 4 tidal locks on the River Trent by Trentlink, sponsored and supported by CRT and The Boating Association for the guidance of skippers of low-powered craft, and those inexperienced on the river.
While looking familiar to inland boaters, this gauge sits on top of the lock. It is used by either the lock keeper or by individual skippers referencing the water level above the tidal section which is continually monitored by an Environment Agency Flood Gauge, and which is easily accessed via a QRC code on top of the sign via a smartphone. The system has already effectively predicted when levels somewhere on the 43 miles of river have overtopped its banks, and/or the incoming tide has failed to generate the ingoing current needed by low power craft to use the river comfortably.
These new signs are in place at all 4 tidal locks between Cromwell & Keadby plus one will be in place at Town Lock when manned.