In Maryland, the general rule for liability related to surface water runoff is referred to as the civil rule which states the higher elevation land owner has the right to have his or her surface water flow naturally over the lands of a lower elevation landowner and the lower elevation owner has no right to prevent the flow. This means that lower elevation landowners cannot install berms or other features to prevent the natural flow of water over their property. Yet the civil rule also states that while higher elevation landowners have the right to have surface water flow over their properties onto lower properties, these landowners are not permitted to increase either the amount or volume of water flowing onto lower lands.
The application of the civil rule can have harsh results. To soften some of the harshness of the civil rule, Maryland courts have adopted a “reasonableness of use” test. This test involves an analysis of the benefit to the higher elevation landowner vs. the harm to the lower elevation landowner so that the lower elevation owner is not unreasonably denied use of his property. The “reasonable of use” test does not replace the civil rule but allows courts to incorporate conditions into a judicial decision to reduce harm caused to a lower elevation property when the higher elevation landowner is acting in an unreasonable way. The reasonableness of use test has resulted in Maryland courts finding higher elevation landowners to be in the wrong for:
(1) increasing the quantity or volume of water discharged onto the lower land;
(2) discharging water in an artificial channel or in a different manner than the usual and ordinary natural course of drainage;
(3) putting water on the lower land which would not have flowed there if the natural drainage conditions had not been disturbed;
(4) causing dirt, debris, and pollutants to be discharged onto the lower land; or
(5) otherwise creating a health hazard.
What legal claims can a lower elevated landowner bring in a civil lawsuit against a higher elevated landowner who has done any of the above? The claims include trespass, nuisance, and/or negligence to stop the harmful drainage, and to get financial damages to compensate for any injury to property. Although the flow of water might not be what comes to mind when the legal concept trespass is used, a civil trespass occurs when a person interferes with another’s interest in property by entering or causing something to enter the land. Therefore, by changing the flow of surface water and causing the water to drain onto another person’s property, the person who changed the flow has interfered with his neighbor’s interest in that property and caused a trespass to occur. *Taken from Maryland Risk Management Education Blog*