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Do you have a right to block surface water from entering onto your property? Can you modify a natural watercourse? Are you legally obligated to prevent surface water on your property from travelling onto your neighbour’s property? Rural landowners are often confronted with these perplexing issues. The below guide may assist cottagers and other rural landowners in answering some preliminary questions about drainage rights in Ontario.

Some definitions: Surface water versus natural watercourses

The common law makes a distinction between surface water and natural watercourses. According to the Ontario Court of Appeal in McLennan v. Meyer, [2005] O.J. No. 4665, a natural watercourse is a watercourse with “a definite channel with banks or sides with a bottom or bed where water runs seasonally or all year round”. A natural watercourse need not necessarily “originate exclusively as a work of nature”. According to the Superior Court of Justice in McLennan v Meyer [2004] O.J. No. 510, aff’d [2005] O.J. No. 4665, if a permanent man-made watercourse has a defined bed, visible banks, and a recurrent water flow, it should be considered a natural watercourse if it has been maintained for a sufficient length of time.

Surface water, on the other hand, is water that is not contained. 

The common law ascribes different drainage rights and obligations to landowners depending on whether the landowner is dealing with surface water or a natural watercourse.

The natural drainage principle

At common law, where surface water naturally accumulates on one property and, “by operation of the laws of nature” passes onto a neighbouring property, the owner of the receiving property has no legal complaint.1 A landowner does not cause a nuisance if the landowner allows surface water to flow naturally across his or her land to a neighbour’s land.2 The mere transfer of surface water from one property to another is not actionable at common law.

This principle can be traced to the English decision of Rylands v Fletcher (1868), L. R. 3 H. L. 330, where the House of Lords stated:

If, in what I may term the natural user of that land, there had been any accumulation of water, either on the surface or underground, and if, by the operation of the laws of nature, that accumulation of water had passed off into the close occupied by the Plaintiff, the Plaintiff could not have complained that that result had taken place. If he had desired to guard himself against it, it would have lain upon him to have done so, by leaving, or by interposing, some barrier between his close and the close of the Defendants in order to have prevented that operation of the laws of nature.

This principle is sometimes referred to as the “natural drainage principle”. According to the Honourable Gérard La Forest in his chapter in Anger & Honsberger Law of Real Property 3rd ed, the natural drainage principle provides that higher land may drain onto lower land through the forces of nature without giving a cause of action for injury resulting from that flow to the owner of the lower land.3

According to the District Court of Ontario in Laughren v. Lachance, 1988 CanLII 4538 [1988], O.J. No. 1320, the natural drainage principle provides that landowners have no obligation to construct a system of drainage to prevent the natural flow of surface water from encroaching onto adjoining properties.

In Groat v. Edmonton (City), 1928 CarswellAlta 116, [1928] 3 D.L.R. 725 the plaintiff complained that the defendant City’s infrastructure caused inordinate amounts of surface water to accumulate on the plaintiff’s property. The surface water in this case transmitted horse droppings and other waste from the City streets to the plaintiff’s property. While the Supreme Court of Canada ultimately found the City liable for the nuisance caused by the horse droppings and other waste, the court opined that the City had no obligation to intercept rain water that pursued its way towards a water course “under the impulsion of gravity”. The court held that owners of land are not obligated to drain their lands into a water course.

Natural drainage versus artificial direction of water

The natural drainage principle only shields upstream riparian owners from liability for the natural flow of surface water. The principle does not protect owners who actively direct water onto adjoining properties.

The Ontario High Court in Berry v. Trinidad Leaseholds (Canada) Ltd. 1953 CarswellOnt 282, [1953] O.J. No. 191 stated that while upgradient riparian owners may dispose of surface water on their property as they see fit, such owners cannot by artificial drains or ditches collect water on their land and cast it on the downgradient property to the downgradient property owner’s injury.

In Smith v. Autoport Ltd, 1973 CanLII 1242 (NS SC), the Nova Scotia Supreme Court stated that an upper riparian owner cannot, by artificial means gather water on his or her property and “throw it upon his neighbour’s land”.

The British Columbia Supreme Court in Allison v Radtke, 2014 CarswellBC 2884, 2014 BCSC 1832 expanded on this principle, stating that not only can an upper riparian owner not direct water by artificial means onto adjoining properties, they are also not permitted to alter their lands so that it increases the amount of surface water running onto a neighbour’s property.

In Loring v Brightwood, the Nova Scotia Court of Appeal opined as follows:

I am, respectfully, not convinced that the Goldman case or any principles of urban planning in Canada in the twentieth century require the owner of vacant urban land to take positive steps to ensure that surface water on his land does not run off to the possible injury of his neighbour, so long as he does nothing materially to increase or change the direction of the flow.” [emphasis added]

No obligation to receive surface water

Despite the above-noted immunities for upgradient property owners, the natural drainage principle also provides that absent any prescriptive rights, downgradient property owners are under no obligation to receive surface water traveling from higher, upstream, properties. Accordingly, lower riparian owners may block and repel the surface water travelling onto their properties.5

The case law indicates that the owner of downgradient land owes no servitude to the owner of upgradient land to receive the latter’s drainage.6 The Ontario Superior Court of Justice in Alfarano v. Regina, 2010 ONSC 1538 opined that the doctrine of dominant and servient tenements does not apply to the flow of surface water precipitated by snow or rain between adjoining lands of different grades. According to the Court in Alfarano, the owner of the land of a higher grade enjoys no right to have surface water falling on his land discharged over the land of the lower level.

The Ontario Superior Court of Justice in DiGreggorio v. Osborne, 2004 CarswellOnt 2050, [2004] O.J. No. 2156 undertook a comprehensive analysis of right of downgradient riparian owners to repel surface water from their properties. While the Court in DiGreggorio acknowledged that downgradient riparian owners may repel surface water even if such action results in the flooding of the upgradient property, the Court found that the right to block surface water is not an absolute right. The Court concluded that any blocking must be done in pursuit of a proper, or reasonable, purpose and cannot be done gratuitously or maliciously without any regard to the interest of the neighbour. According to the Court, when blocking the flow of surface water the owner of the downgradient land is to do no more than is reasonably necessary to protect his or her land.

Blocking surface water versus natural watercourses

Downgradient property owners are permitted to block any surface water that enters onto their property, but, absent any prescriptive rights, are not permitted to block any natural watercourse. The Ontario High Court of Justice in Steele v. Lofranco, 1955 CarswellOnt 166, [1955] O.W.N. 350 articulated this distinction as follows:

If by raising the level of his lands the defendant interfered with a natural watercourse to the injury of the plaintiffs, he is liable, but if such waters were mere surface waters not flowing in a defined channel, he owed the plaintiffs no obligation to receive the drainage and is not liable unless he was negligent or created a nuisance”.

I am satisfied that the water that was dammed back at the boundary-line between the properties and which caused the flooding of the plaintiffs’ basement was rain-water that found its way into the depression by force of gravity. Such water was mere surface or casual water which the defendant had the right to stop at the southerly limit of his property”.

The Ontario Court of Appeal re-emphasized this principle in McLennan v. Meyer, 2005 CarswellOnt 5645, [2005] O.J. No. 4665 where the court concluded:

It is common ground that, while the appellant may be entitled to block surface water drainage from the respondents’ property, he is not entitled to block a natural watercourse running from the respondent’s property onto his.”

Recourse under the Drainage Act, R.S.O. 1990, c. D.17

In addition to the above-noted common law rights and obligations, landowners affected by drainage issues may have recourse under the Drainage Act. When a “majority” of landowners (as defined in the Drainage Act) in an area submit a petition to the council of a municipality for the construction of a drain, the council may appoint an engineer for the design and construction of a municipal drain.7 According to the Drainage Act, a “majority” of landowners is either a majority in number of property owners in the area requiring drainage; or, owners, representing at least 60 percent of the hectarage in the area requiring drainage.8

Once a petition has been submitted, the council of the municipality is required, within thirty days after the filing of the petition, either accept or decline the petition and notify the petitioners of its decision.9 If the council does accept the petition, it must notify the local Conservation Authority, or if no Conservation Authority has jurisdiction, the Minister of Natural Resources and Forestry.10

Once a petition has been accepted and an engineer has been appointed, the engineer prepares a report setting out the drainage works and providing cost estimates for the proposed works. The engineer allocates the cost of the drainage works to every owner of land that will be drained (drainage area) by the drainage works, even if those owners did not sign the initial petition. The cost of the drainage works is allocated to landowners based on how much their property will be drained and the amount of water they are accepting from upstream property owners for the drainage works.11

Landowners whose properties will be drained by drainage works, even if the landowner has not signed the initial petition for the drainage works, will be assessed for the costs of the works, including the costs associated with preparing the engineer’s report, municipal administration and constructing the works. In addition, any lands that are more easily maintained as a result of the drainage works, even if the property is not directly drained by the works, will be assessed for a portion of the cost of the drainage works.12


Drainage law, while obscure, is a fundamental feature of land ownership in rural Ontario. The above-noted common law and statutory rights may be helpful in navigating disputes that arise over the flow of water in rural areas.

Alfarano v. Regina, 2010 ONSC 1538 (CanLII); Rylands v Fletcher, (1868), L. R. 3 H. L. 330; DiGregorio v. Osborne, 2004 CarswellOnt 2050; Groat v. Edmonton (City), 1928 CarswellAlta 116, [1928] 3 D.L.R. 725, [1928] S.C.R. 522; Roy, Roy and Manderson v. St.John’s Metropolitan Area Board, [1984] N.J. No. 317.

Allison v. Radtke, 2014 CarswellBC 2884, 2014 BCSC 1832; Laughren v. LaChance (Dist. Ct.), 1988 CanLII 4538 (ON SC).

3 Anne Warner La Forest, Anger & Honsberger Law of Real Property, 3rd ed (Thompson Reuters, 2006) (loose-leaf 2017 supplement), ch 19 at 19:60.

4 Laughren v. LaChance (Dist. Ct.), 1988 CanLII 4538 (ON SC); Anne Warner La Forest, Anger & Honsberger Law of Real Property, 3rd ed (Thompson Reuters, 2006) (loose-leaf 2017 supplement), ch 19 at 19:60.

5 Anne Warner La Forest, Anger & Honsberger Law of Real Property, 3rd ed (Thompson Reuters, 2006) (loose-leaf 2017 supplement), ch 19 at 19:60.

6 Ostrom v. Sills, 1 C. & S.D. 387, 24 O.A.R. 526, aff’d 28 S.C.R. 485.

7 Drainage Act, RSO 1990, c D.17, s 4.

8 Drainage Act, RSO 1990, c D.17, s 4.

9 Drainage Act, RSO 1990, c D.17, s 5.

10 Drainage Act, RSO 1990, c D.17, s 5.

11 Drainage Act, RSO 1990, c D.17, ss S.8(1)(c), s.21, 23.

12 Drainage Act, RSO 1990, c D.17, s 22.

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