Hydrographic Survey for Hanson
Hanson UK are part of the HeidelbergCement Group, which is one of the largest building materials manufacturers in the world. Already happy with our efficient monthly stockpile surveys of coal, gypsum, limestone and clinker at their site, our client approached us to undertake a survey of a large pond – the natural outcome of an old quarry pit.
Hydrographic surveys are used to measure water depth and assess the bottom configuration of bodies of water by collecting data efficiently and accurately. They are commonly used for measuring beds at sea with advanced sonar systems, but this project required a more hands-on approach.
The survey collected data on the water depth as well as the soft bed (silt) and hard bed levels of the pond. This 44m-wide pond had a large amount of bankside vegetation which created a challenge for us, so we had to look at new ways to get the accurate data for our client.
Whilst the rest of the team was pondside, another team member stood on the platform of a cherry picker. This had been placed at the side of the pond so the platform could reach across the water. The cherry picker allowed us to hover above the water to check the water depth and silt levels with a depth gauge across multiple points of the pond.
Along with the depth gauge, this hydrographic survey was conducted using some of the latest technology, including a Geomax station. Once completed, we presented our client with the data in a visual format that would accurately show all of the water depth and soft bed and hard bed levels.
Why didn’t we use a drone or sonar systems? While using a LiDAR drone would’ve shown the depth of the water, it would’ve only provided half of the picture as it’s unable to show the silt levels – the same applies to sonar systems. Neither would have provided the accurate results that this more hands-on approach achieved.