Foudry Brook rises at springs between the small villages of Heath End and Baughurst, where it is known as Bishop's Wood Stream. It flows eastwards though Tadley, and is briefly culverted under housing on Elmhurst before emerging back on the surface and passing under the A340 Mulfords Hill road. It then enters a much longer culvert under Tadley Bottom, and emerges into open countryside on the east side of Bowmonts Bridge. It crosses the Pamber Forest nature reserve, becoming the Silchester Brook, and turns to the south, where Silchester Sewage Treatment Works is on the right bank. It then passes between two earthworks before Honeymill Brook joins it on the right bank. The linear earthworks were associated with a Late Iron Age town that developed into the Roman town called Calleva or Silchester. They are and long, with a gap of where the river passes through.