In Pennsylvania, there is a surface water law that is in legal case law. That is, a municipality or other property owner is liable for damage to an adjoining property if that first owner or municipality artificially diverts or channels surface water (including stormwater) onto that adjoining property.

Even if there is no additional volume of water, if stormwater is diverted and results in increased intensity or concentrated flow, there is liability if damage occurs.

A municipality has the right to manage stormwater and protect public health and safety. However, you must balance that against the rights of adjoining property owners.

If a storm drainage system or runoff pipes are negligently constructed so that they do not adequately control runoff, there is liability for damages caused.

This can be found in the Pennsylvania Stormwater Management Act (32 PS Section 680.13 et seq). The Act requires that a plan be in place to manage stormwater runoff resulting from construction that involves drainage or alteration of stormwater runoff.

If the soil disturbance from a construction project is large enough, or if the soil disturbance is close enough to a protected waterway, then a permit and/or soil erosion control plan must be filed with the Pennsylvania Department of Environmental Protection.

Therefore, there are two main things to keep in mind that can give rise to a legal claim in Pennsylvania regarding stormwater. First. If you are doing construction that involves a large amount of soil disturbance or is near a protected creek or waterway, you should determine if you need a permit and soil erosion control plan. Second, if you own a home or land where you believe stormwater or surface water is being diverted onto your property with increased flow or intensity, then you may file a claim if you have resulting damage.

In the second case, if you think your property is being damaged or a person has been injured, then you should investigate the source of the problem. If there is recent sewer or drainage construction, you should check with both your local government and the Pennsylvania Department of Environmental Protection. Find out what the project consisted of and if a permit and/or soil and erosion control plan was required. Even if a permit or plan was not required, it may still be a violation of the Stormwater Management Act or Pennsylvania case law if the surface water diversion was negligently constructed or otherwise artificially channels water into a increased flow or velocity to your property. .

In such legal claims, there may be legal causes of action for: negligence, trespass, nuisance, or violations of the PA Stormwater Management Act or the PA Clean Streams Act. The Clean Creeks Act (35PS Section 691.1). The Clean Streams Act allows for legal claims by private citizens for polluting runoff into a waterway. It is most often applied to the Pennsylvania Department of Environmental Protection or other government actions against polluters.

Generally, a legal claim involving an argument that there was a negligently constructed drainage or stormwater system or artificially channeled runoff requires the use of an engineer. That engineer would have to inspect and possibly do a study to compile the engineering findings to support the claims.