Who Is Responsible When Uphill Storm Water Causes Downhill Damage?
by Miles J. Dolinger
May 23, 2011
Stormwater issues are not new to residents of hillside and mountain areas. Because winter storms often bring voluminous amounts of rain, sometimes for weeks on end, it is important to know how and where all that stormwater is flowing through your property in order to protect structures from damage and to protect the land from erosion. Sometimes stormwater needs to be collected, concentrated and discharged elsewhere through pipes or culverts, especially following new construction or the creation of impermeable surfaces (like roads and driveways).
But what if the measures you take to prevent stormwater damage to your property negatively impact your downhill neighbor? In many cases, the uphill landowner will be liable for any actual damages he or she causes downstream.
General Rule: an uphill landowner is liable for damages caused to downhill property resulting from surface water that the uphill owner alters from its natural course, unless the downhill owner acts unreasonably.
The rule of liability when surface stormwater causes damage to downhill property is well-settled in California: The owner of uphill land is not liable for any damage caused by stormwater that flows from his/her land along its natural course. An uphill owner, however, is liable for any damage caused to others’ property by the discharge of water in an unnatural manner; that is, when the uphill owner has altered the natural course of the stormwater.1
This rule is modified by a consideration of the reasonableness of the owners of both the uphill and the downhill properties. One court has explained that, "(i)t is therefore incumbent upon every person to take reasonable care in using his property to avoid injury to adjacent property through the flow of surface waters. Failure to exercise reasonable care may result in liability by an upper to a lower landowner. It is equally the duty of any person threatened with injury to his property by the flow of surface waters to take reasonable precautions to avoid or reduce any actual or potential injury.”2
However, if both the uphill and the downhill landowners have acted reasonably, the uphill owner will be liable.3 This analysis is referred to as the “modified civil rule,” and it is a rule of negligence, as opposed to a property law-type rule like trespass.4 If a lawsuit ensues and a court finds the uphill owner to be liable, he/she may be ordered to fix the problem, pay the costs of correcting any actual damage caused, and/or compensate the downhill owner for any depreciation in value caused to the downhill property.
The question of reasonableness of conduct considers both the actor’s interest and the effects of the actor’s conduct upon others. It is a question of fact to be determined on a case-by-case basis, considering factors such as the amount of harm caused, the foreseeability of the harm which resulted, and the purpose or motive with which the landowner acted.5 The question of the parties’ reasonableness may get complicated depending on the specific factual scenario. For example: when there are multiple sources of uphill stormwater, when the stormwater discharge was planned or engineered not by the uphill owner but by his/her contractor, when the uphill owner was protecting his or her property from uphill, collected stormwater, or when the damage was the result of an “Act of God” (which is other than simply heavy rain).
Public Entity Liability: a public entity can be liable for negligence or inverse condemnation for stormwater discharges from a public improvement.
If the source of the uphill stormwater is a public improvement (for example, a drain or pipe owned or maintained by a public entity), the public entity can be held liable for damages under the modified civil rule discussed above. In addition, the public entity can be held liable under an inverse condemnation theory. “Inverse condemnation liability ultimately rests on the notion that the private individual should not be required to bear a disproportionate share of the costs of a public improvement.”6 Under this cause of action, the downhill owner would be required to prove that the public entity’s conduct with regard to its public improvements posed an unreasonable risk of harm to the downhill property, and that the public improvements were a substantial cause (but not necessarily the sole cause) of the damage to the downhill property.7
Some Questions to Ask in Evaluating a Potential Claim or Defense Concerning Damages Caused by Uphill Stormwater
Here are some facts to consider in evaluating a potential claim relating to the discharge of concentrated stormwater from above:
- Was the water problem the result of the uphill landowner(s) changing the natural course of surface water (stormwater)?
- Was the upper owner’s conduct reasonable, considered in relation to potential impacts on your property?
- Did you do anything to contribute to the damages? Is there some action you could have taken to prevent or minimize the damages, but chose not to do? Why/why not?
- When did you actually discover the water problem? Would a reasonable person have discovered it earlier?
- Was the source of the collected stormwater an uphill structure that is owned or maintained by a public entity?
- Was the natural flow of surface water altered not by the uphill landowner, but by his/her contractor?
- Does the uphill owner have a drainage easement across your property?
- Does the water problem have negative impacts on other people or properties? (Is it a public nuisance?)
It is important to be mindful about how you alter the natural surface flow of stormwater and what impacts the discharge of that stormwater may have on downhill property. Liability for accidental property damage can be avoided by implementing a responsible stormwater plan, or cooperating with your neighbors in developing a joint stormwater plan.
If the uphill property owner is collecting and discharging stormwater without regard to its downhill impacts, then the law would generally hold the uphill owner responsible for any damages caused.
Finally, note that homeowners’ insurance policies may not cover either the uphill owner or the downhill owner for these types of man-made damages.
1Keys v. Romley (1966) 64 Cal.2d 396, 405-06.
2Id. at 409.
4The downhill plaintiff may also have causes of action for nuisance and/or trespass, although those topics are beyond the scope of this article.
5Keys v. Romley, supra, 64 Cal.2d at 409.
6Locklin v. City of Lafayette (1994) 7 Cal.4th 327, 368.
7Skoumbas v. City of Orinda (2008) 165 Cal. App. 4th 783, 792-93; See also Locklin v. City of Lafayette, supra.