Legal Question in Real Estate Law in California

Re: Civil code dealing with property water drainage

You are not going to find much help in the Civil Code. A lot of the law in California regarding runoff from higher parcels is judge-made law (common law), and you need to refer to the printed decisions. A leading case is Keys v. Romley, decided by the California Supreme Court in 1966 and found in 64 Cal.2d at page 396.

The general rule is that the owner of the lower parcel must accept the natural runoff from the upper parcel, but the owner of the upper parcel must not 'increase the burden' on the lower parcel by artificial modifications to the natural drainage. In the Keys case, the court recognized that this rule, if strictly applied, would inhibit development. It imposed a 'rule of reason' on both property owners. The upper owner may develop her land but must do so with reasonable precautions to avoid unnecessary harm to downhill owners. Similarly, the downhill owner must respond reasonably to uphill development. In other words, when a small ditch or a small dike would prevent flooding, the downhill owner must take this action rather than just letting damage occur and then suing.

This will give you a bit of the flavor of the law and the courts' position on runoff problems. The application of these 'rules of reason' to any real-life situation is complex and you may need the assistance of a real-estate lawyer to find,interpret and apply the law in your situation.