Drainage CCTV surveys are set to take place on a Croxley Green roundabout next week.
Covers in the roads will be lifted so surveys can be carried out to assess the condition and position of the sewers along Watford Road and Baldwins Lane.
The work is part of investigations into the Croxley Rail Link.
Residents are being warned of noise as jetting works might be undertaken if engineers encounter blockages in the existing sewers.
The work will be carried out from April 29 to May 2 between 9.30am and 4.30pm.
Motorists can expect lane closures, carriageway narrowing and stop/go boards.