Drainage surveys: inlets, manholes and lines on the map

Drainage information is often split between old drawings and the memory of operations staff. To plan cleaning before winter or deal with local flooding, you need to know where every inlet and manhole is and how they connect to the network.

We mapped the drainage elements on the aerial photo and built separate GIS layers for inlets, drainage manholes, drainage lines and the inlet lines that connect them to the network. One authority received a drainage-survey dashboard that brings the data together; the other received a city-wide survey map with a legend.

Engineering and operations teams see the drainage network on the map, locate any inlet or manhole by position and plan maintenance from the layers instead of searching through drawings.