Pumping test at a famous London Landmark


Project Dewatering Limited (PDL) were appointed by the client to undertake a pumping test at the famous Tower of London grounds. The purpose of the pumping test was to measure the yield of a historic brick-lined chamber to aid the client in understanding if the chamber could be used as a source of water for the moat redevelopment scheme.

The works

The pumping chamber was equipped with a 220V – 240V, 0.81 kW submersible borehole pump (E-Tech M5L). The pump was coupled to a 50mm flexible riser pipe which, in turn, was connected to the wellhead. The wellhead rested on a temporary manhole cover which included a pump flow control valve.

The wellhead was connected to 2” discharge pipework with the length from the chamber location to the discharge point being approx. 15m. The discharge pipe included 1 no. additional 2” valve, a pulse flowmeter (Octave DN 50) and a stopcock for water sample extraction.

PDL performed a series of pumping tests on the chamber which included an equipment test, step test, short duration and long duration tests. Tests were conducted and data obtained as per the BS ISO 14686:2003 standard.


The final report included all processed data, presented in a clear structure, along with the methodology of the pumping test, the program of PDL’s on-site activities, summarised graphs and tables, and the final results, conclusions, and recommendations. The client is now considering redeveloping the well with follow up tests in September.