Water level marker, Loxley river, Sheffield, UK

This is a substantial stone, inscribed with the words "MARK BELOW TWO FEET ABOVE WEIR -- AS AGREED 1825". There is a flat surface, 14cm wide by 12cm deep, perpendicular to the inscribed surface. The distance is 18" or 45.5cm from this flat to the line below the text (the line that is presumably the MARK BELOW). The stone currently lies on the Loxley Valley Trail, a few miles west of Sheffield, UK. It presumably stood upright in 1825 to mark an agreed water level -- I'll discuss this in a comment. The reconstruction used Meshroom and Meshlab software, from photos taken in March 2021. Source: Objaverse 1.0 / Sketchfab