Hobson's Conduit Trust

Running the Runnels 2024

The Eastern runnel carrying clean fresh water past Pembroke

After two years when the winter recharge was less effective, and the hot and dry summer of 2022, we took the decision to attempt to operate the Runnels in 2024, especially in view of the winter and spring rainfall.  Water flowing from Nine Wells is currently some 15 litres/sec – 50% -higher than at the same time in 2022.

However, the problems of misalignment of the West side Runnel in various places, especially at the Grove Lane and Little St Mary’s Lane crossings, remain challenging.  Even a minor blockage causes water to back up, and creates a flood.

The East side Runnel is much sounder, creating a very pleasing flow as the photograph shows.  We had considerable help from the Cambridge City Council drainage engineers and road cleaning colleagues, and from our contractors ADC Drainage in preparing for this year’s Runnel operation.

Our efforts to reduce the West side flow whilst emphasising the East side have been only partially successful, and we have now been obliged to shut down the flow after two weeks in response flooding incidents.

We may make a further attempt to operate the Runnels, which are a feature greatly appreciated by residents and visitors alike, in June this year.

In the longer term we need to address the alignment issues, particularly on the West side.  The Runnels are Listed and we are in discussions with Cambridge City Council, and Cambridgeshire County Council as we develop a plan for restoration.  Given the volume of traffic using Trumpington Street daily, particularly inbound to the City on the West side, this will be a major project.