The ‘ad medium filum’ rule
The ‘ad medium filum’ rule

The following Property guidance note provides comprehensive and up to date legal information covering:

  • The ‘ad medium filum’ rule
  • When does the ‘ad medium filum’ rule apply?
  • Highways maintainable at the public expense
  • Rivers and streams
  • Tidal rivers
  • Rebutting the presumption
  • Registered land
  • Miscellaneous

The ‘ad medium filum’ rule is a rebuttable presumption that an owner of land which abuts either:

  1. a public or private highway, or

  2. a non-tidal river or stream

also owns the soil of the adjoining highway, or the bed of the adjoining river or stream, up to its centre line. A transfer or lease of that land will therefore be presumed to include that part of the highway, river or stream without the necessity for any express mention of it.

In the case of a highway, the presumption is known as the ‘ad medium filum viae’ rule, and is based on a combination of convenience (so as to prevent disputes as to precise boundaries) and also on the supposition that each owner contributed a portion of land when the highway was formed. In the case of a river or stream, the rule is known as the ‘ad medium filum aquae’ rule, and appears to be based solely on convenience.

When does the ‘ad medium filum’ rule apply?

The presumption applies even though the land conveyed:

  1. is marked on an accompanying plan with coloured edging which does not include the highway or river, or

  2. is described as being ‘bounded by’ the highway or river, or

  3. is stated (either in the body of t