We recently had cause to do some digging in relation to legal provision of depth gauge markers now they are no longer prescribed. I thought our findings may be of use to others-
Under the TSRGD 2002 depth gauge markers were prescribed signs (Diagram 826 and 826.1). The depth gauge marker is no longer prescribed in the TSRGD 2016.
Use of the markers is covered in Traffic Signs Manual Chapter 4 (Section 10.1.5). This Chapter refers to authorisation by the appropriate National Authority (TSM Chapter 1 defines the National Authority as DfT). Advice from the DfT, in that regard, is that it is for each authority to decide if such a marker is needed and if the decision was taken that it was, the authority would now be placing a measuring device, rather than a traffic sign, and authorisation is not required.
While the advice we received was in contrary to that included in the TSM, we found further legislation to support placing of these measures that we intend to use for future installations.
Depth gauge markers may be placed (without authorisation), where appropriate, in accordance with our duties under the Highways Act Section 103-
Provision of posts to indicate depth of flood water.
(1) It shall be the duty of a highway authority to provide, in connection with any highway for which they are the highway authority and which is subject to flooding to any considerable depth, graduated posts or stones in any case where they consider the provision thereof necessary or desirable for the purpose of indicating the depth of water covering the highway.
(2) A highway authority may alter or remove any post or stone provided by them under this section.