Easements - Actionable Encroachment. Oakville (Town) v. Sullivan
In Oakville (Town) v. Sullivan (Ont CA, 2021) the Court of Appeal stated principles for deciding when there is an 'actionable encroachment' to an easement:
 Once the nature and extent of the easement have been determined, the court then considers whether there is an actionable encroachment upon it. The test for an actionable encroachment is whether there is a “substantial interference” with the use and enjoyment of the easement for the purpose identified in the grant: Weidelich v. de Koning, 2014 ONCA 736, 122 O.R. (3d) 545, at paras. 9-11; Fallowfield, at paras. 40-41; Hunsinger v. Carter, 2018 ONCA 656, 91 R.P.R. (5th) 175, at para. 11; Anne Warner La Forest, Anger & Honsberger, Law of Real Property, loose-leaf, 3rd ed. (Toronto: Thomson Reuters, 2019), at para. 17:20.50; and Halsbury’s Laws of Canada – Real Property (Toronto: LexisNexis Canada, 2016 Reissue), at HRP-325.. Weidelich v. de Koning
In Weidelich v. de Koning (Ont CA, 2014) the Court of Appeal considered when an encroachment was actionable:
A: Is There An Actionable Encroachment?
 The application judge, referring to Canadian and English authority, found that there was not an actionable encroachment. He held that an encroachment on a right-of-way is actionable only if there is a substantial interference with the use of the right-of-way as granted. Quoting from West v. Sharp (1999), 79 P. & C.R. 32 (C.A.), the application judge said, at para. 24:
There is no actionable interference with a right of way if it can be substantially and practically exercised as conveniently after as before the occurrence of the alleged obstruction. I agree with the reasons of the motion judge. The authorities he cites and others fully support the conclusion that an encroachment on a private right-of-way is actionable only where the encroachment substantially interferes with the dominant owner’s ability to use the right-of-way for a purpose identified in the grant. Gale on Easements, 19th ed. (London: Sweet & Maxwell, 2012), the leading English text on the topic, puts it this way, at para. 13-06:
As regards the disturbance of private rights of way, it has been laid down that whereas in a public highway any obstruction is a wrong if appreciable, in the case of a private right of way the obstruction is not actionable unless it is substantial. Again, it has been said that for the obstruction of a private way the dominant owner cannot complain unless he can prove injury; unlike the case of trespass, which gives a right of action though no damage be proved. In Hutton v Hamboro, where the obstruction of a private way was alleged, Cockburn C.J. laid down that the question was whether practically and substantially the right of way could be exercised as conveniently as before. [Emphasis added.] Lord Cockburn’s language echoes through the English and Canadian case law: see, e.g., Clifford v. Hoare (1874), L.R. 9 C.P. 362; Pettey v. Parsons,  2 Ch. 653 (C.A.), at 662, 665-6, 667-8; Keefe v. Amor,  1 Q.B. 334 (C.A.), at 347; Celsteel Ltd. v. Alton House Holdings Ltd.,  1 W.L.R. 204 (Ch.), at 216-18, rev’d on other grounds,  1 W.L.R. 512 (C.A.); B & Q Plc. v. Liverpool and Lancashire Properties Limited,  E.W.H.C. 463, 81 P. & C.R. 20 (Ch.); Devaney v. McNab (1921), 1921 CanLII 557 (ON CA), 69 D.L.R. 231 (Ont. C.A.); Voye v. Hartley, 2002 NBCA 14, 247 N.B.R. (2d) 128, at para. 25; Donohue v. Robins, 2012 ONSC 2851,  O.J. No. 2133, at para. 58; Lester v. Bond, 2013 ONSC 7888,  O.J. No. 6006, at paras. 30-33.
 The requirement that the dominant owner prove substantial interference to maintain a claim reflects the nature of the dominant owner’s right. He or she does not own the right-of-way or the land upon which the right-of-way runs, but only enjoys the reasonable use of that property for its granted purpose. The dominant owner may only sustain a claim predicated on substantial interference with that reasonable use. The distinction is between the rights of ownership and the right of reasonable use for an identified purpose.
 Lord Brett, in Clifford v. Hoare, focused on the distinction between the rights of ownership and the right of reasonable use for an identified purpose in explaining why a dominant owner had no claim even though a building encroached some two feet onto the 40-foot right-of-way:
[T]hat which is granted to the plaintiff by the conveyance of the 2nd of August, 1872, was, not a forty-foot road, nor the exclusive use of a forty-foot road; but a right to use it in common with others. He was to have an easement in the nature of an access or right of way over the road, by himself and his friends and servants, and nothing but an easement. If this were a grant of the road itself, any interference with the plaintiff’s enjoyment of it would, no doubt, give a right of action. But all that is granted here is a right to a reasonable use of the road by the plaintiff in common with others, who have equal rights with him; and I am of opinion that no substantial interference with his exercise of that easement has been made out. [Emphasis added.] A court, when deciding whether an encroachment results in a substantial interference with the claimant’s use of the right-of-way, will have regard to the terms of the grant and the nature of the encroachment. The determination is a factual one and will turn on the specific circumstances of each case.
 The significance of an encroachment depends on its impact on reasonable use. The dominant owner is entitled to every reasonable use of the right-of-way for its granted purpose. I would adopt as correct the inquiry captured in the following passage in B & Q Plc., at 257:
In short, the test, … is one of convenience and not necessity or reasonable necessity, Provided that what the grantee is insisting on is not unreasonable, the question is: can the right of way be substantially and practically exercised as conveniently as before? The facts of Celsteel Ltd. provide an excellent example of the proper application of the substantial interference test. In Celsteel Ltd., the defendant lessee of the property decided to build a car wash that encroached on a right-of-way the plaintiffs used to access their parking garages. The defendant argued that the encroachment was not substantial as it related to one of the plaintiffs because, although the plaintiff would have to drive into and reverse out of the garage, contrary to his habit of reversing into and driving out of the garage, the plaintiff could still access his garage.