The general rights of law applicable to adjoining properties apply in respect of support from adjacent land and mines. The right of support is the right to have the surface maintained at its historical and natural level. It is not an easement but a natural right incident to ownership of the soil. The right of support remains on severance of the minerals and the surface.
The owner of land may by appropriate wording grant the minerals with the right to let down the surface and working them. He may by exceptions and reservations of the minerals, or the power of working grant the surface so that the right to support does not arise, depending on the terms.
The right of support is independent of the type of strata involved, the difficulty of propping up the surface or comparative values of the surface and minerals. The surface owner’s right is not modified by the fact that the obligation not to cause subsidence makes working of the mines, minerals impossible or unprofitable.
There is no modification of the surface owner’s rights where the supported land contains strata of an unstable nature which shift and cause subsidence if the adjoining owner excavates on his land.
The owner of minerals is entitled as an incidence of his enjoyment of property to get the minerals in usual and proper course of working consistent with but leaving support. The minerals may be worked out provided adequate artificial support is substituted.
The area subject to the obligation of support is not limited to the land immediately adjoining, if that land in its natural condition is insufficient to form support. Accordingly, persons whose land in a natural state affords support may be subject to the right. If an adjoining area which affords support is excavated, no right to a support is acquired against a more adjacent area than affords support in the altered circumstances.
This presumption that the owner of the surface is entitled to support for underlying minerals is not dependent on the manner of severance. It is applicable whether they have been severed by grant of mines and minerals separate from the land or where the land transfers with the exception of mines and minerals. The instrument may be the grant of a term of lease or a freehold interest.
It is not necessary to prove any special origin for a natural right of support. The burden is on those who deny the right. Where land is acquired, the acquisition of the right must be proved but it is not necessary to allege facts by which a title to such rights may be inferred as a matter of law. It is sufficient to plead the right and the entitlement.
The right of support passes with the land as an incident to it. On severance of the surface from the minerals, it is presumed that it remains.
There is no natural right of support where things are artificially built on the land. Such a right must be acquired as an easement. It may be acquired by grant, implication, express or implied, prescription or statute. Although the easement and the natural right differ in their origin, they are inseparable, and the easement is in effect an enlargement of the natural right.
A statutory right of support was frequently granted by 19th-century statutes, where statutory undertakers were empowered to construct and maintain works such as canals, railways etc.
An express grant or reservation may arise in a mining lease and less commonly in other dispositions of land where the issue appears relevant. A right of support for artificial structures may arise by implication in a deed. If for example the surface is conveyed with a view to erecting buildings, there is an implied right to support.
The purpose need not be expressed in the instrument. The surrounding circumstances may be considered. If it was contemplated that the land might possibly be in the future be subject to an artificial structure in its legitimate inference that the support for that structure is intended to be granted.
A support may be acquired by prescription in accordance with general principles of acquisition of rights by prescription. However, the existence of a contract or instrument between the parties which expressly excludes the right or is inconsistent with it and prevents acquisition.
When land is weakened by excavation of adjoining mines, the same principles apply. If the mines provide adequate support for the buildings before excavation, no right is acquired by prescription against an adjoining owner if twenty years had not lapsed since the excavation of its adjacent mines nor if the adjoining owner is ignorant of the workings.
Where a building has been built over a partially excavated mine, a right is acquired after 20 years against persons interested in the mines if but for working the mines, buildings would not have subsided.
The presumptive right and liability of the surface owners and mineral owners may be varied or modified. There may be an express or implied right to withdraw support. The right of support may be varied by implication. If there is an implication that the minerals are to be worked and it is shown that to the knowledge of the parties at the time of execution, it could not be worked without subsidence, the right of support may be implied. However, the insertion of a general power working by itself even in wide terms is insufficient.
Where the power to get the minerals is subject to payment of compensation for surface damage, right of support of the surface may be thereby varied. However, it is matter of interpretation in the circumstances.
The Railway Clauses Consolidation Act and the Public Health Acts contain provisions in relation to the mine. The rights of the undertakers are the same as those applicable to ordinary individuals acquiring land subject to the statutory modifications. The undertaker is presumptively entitled to such support of the land as is necessary for its condition or when applied for the purpose for which it is acquired. The compensation will include loss of value of mines due to the requirement in lieu of support.
This presumption may be displaced if there is no provision giving the owner compensation from imposing the burden. If there is no provision for compensation to the latter, the right of support will not be presumed.
The Railway and Canal Acts contain specific provisions for mines and minerals. The position is determined by the terms of the Acts and orders of acquisition.
Minerals do not generally impliedly pass in respect of railways and water work acquisitions. At the outset, the railway authority is not generally obliged to make compensation in respect of minerals within the area of protection. It may postpone making compensation until the immediate working of the minerals is possible.
The railway authority has no rights of support for minerals within the area of protection unless and until it is acquired either by purchase of minerals or by payment of compensation for leaving the minerals unworked. If the miner seeks to use the mine, the railway authority may acquire the right of support at that point.
Railway authorities and other bodies purchasing the land under the Lands Clauses Consolidation Act have power to purchase mines and minerals thereunder. Where they belong to the same party, the acquisition is simply part of the acquisition of the land as a whole. However they may also buy mines and minerals which are severed from ownership of the surface.
Purchase may be by agreement or compulsory acquisition powers. The mines and minerals may be separately acquired. The power is exercisable in respect of mines and minerals lying under the land within the limits prescribed by the special Act. After expiry of the compulsory power, the authority may purchase the minerals within such limits by agreement. The purchase must be for the purpose of the works authorized to be constructed.
Provided the authority acts in good faith, it may exercise its powers to acquire land for the purpose of the undertaking.
If the surface subsides by reason of removal of supporting strata, the surface owner entitled to a right of support may take action against the owner of the minerals for the damage caused. This is not based on negligence but based on interference with the property right of the surface owner. Accordingly, fault is not relevant to liability.
If the condition of the surface owner’s land is altered by subsidence so as to interfere with an ordinary enjoyment of his land, he may take action without proof of financial loss. Each new subsidence is an independent claim.
It is necessary to show that the mine owner’s actions or works or omissions have infringed the legal right of the claimant. Questions of causation may arise where a number of owners have removed support.
A person will only be liable if his land supported his neighbours land in its natural state. If subsidence would not have occurred but for the operations of an adjoining owner’s prior operations, he is not liable. The original owner who caused the initial works in breach of the right of support is liable although later workings are the immediate cause of it.
Conversely, that mine owner may be liable for the whole of damage arising from his workings if his land afforded support to the neighbouring land in its natural state even though the damage has been increased by former workings of others or even the injured party.
Damages may be awarded for damage to buildings, notwithstanding that they have not been built with the sufficient solidity relative to the nature of the ground if a right of support in fact exists. It may be relevant to the extent of damages.
The measure of damages is the difference between the value of the land before and after subsidence. Damages may be available for structural repairs and loss of value to property.
Damage to buildings will be included if a right of support has been acquired for the building. If the natural right only exists, the value of buildings maybe recovered if their weight has not contributed to the subsidence. However, the value of a house cannot be recovered if it has fallen by its own weight. Consequence of damages may also be recovered e.g., loss of business etc.
A purchaser may land its actual state and condition unless there has been fraud or concealment.
The personally liable is usually the person who has made the excavation. If this is done by a lessee, the lessee will generally be liable. The lessor may also be liable depending on his responsibilities and the circumstances.
The person who is threatened by a withdrawal of support would be entitled to an injunction to restrain the defendant interfering with the right. It may prescribe limits within which workings are restrained in order to protect the right. An injunction with not be refused on the basis that pecuniary liability will be sufficient.