What are the rights and duties between the owner of the dominant tenement and the servient tenement?

The leading case on the nature of the rights and duties between the owner of the dominant tenement (the respondent) and the servient tenement (the petitioners) is Jones v. Pritchard, [1908] 1 Ch. 630. I adopt the statement of the law made by Parker J. in that case (at pp. 637-8): ... it appears to me that, apart from any special local custom or express contract, the owner of a servient tenement is not bound to execute any repairs necessary to ensure the enjoyment or convenient enjoyment of the easement by the owner of the dominant tenement. The grantor of a right of way over a bridge is not by common law liable, nor does he impliedly contract, to keep the bridge in repair for the convenience of the grantee ... Once again, the grant of an easement is prima facie also the grant of such ancillary rights as are reasonably necessary to its exercise or enjoyment. Thus the grantee of an easement for a watercourse through his neighbour's land may, when reasonably necessary, enter his neighbour's land for the purpose of repairing, and may repair, such watercourse. ... by the common law the owner of the servient tenement is not under any liability for not repairing the subject of the easement, yet there is undoubtedly a class of cases in which the nature of the easement is such that the owner of the dominant tenement not only has the right to repair the subject of the easement, but may be liable to the owner of the servient tenement for damages due to any want of repair. Thus, if the easement be to take water in pipes across another man's land and pipes are laid by the owner of the dominant tenement and fall into disrepair, so that water escapes on to the servient tenement, the owner of the dominant tenement will be liable for damage done by such water. Strictly speaking, I do not think that even in this case the dominant owner can be said to be under any duty to repair. I think the true position is that he cannot, under the circumstances mentioned, plead the easement as justifying what would otherwise be a trespass, because the easement is not, in fact, being fairly or properly exercised.