In Pennsylvania, there is a law of surface waters found in legal case law. That is, a municipality or another property owner is responsible for harm to an adjoining landowner if that first owner or municipality artificially diverts or channels surface water (including storm water) onto that adjoining property.
Even if there is not additional volume of water, if the storm water is diverted resulting in higher intensity or concentrated flow, then there is liability if damages result.
A municipality has the right to manage storm water and to protect public health and safety. However, it must balance that with the rights of adjoining landowners.
If a storm drain system or runoff pipes are negligently constructed such that they do not adequately control the runoff, then there is liability for harm caused.
This can be found at the Pennsylvania Storm Water Management Act (32 PS Section 680.13 et seq). The Act requires that there be a plan in place to handle water runoff resulting from construction that involves drainage or alteration of storm water 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 a soil erosion control plan must be filed with the PA Department of Environmental Protection.
So, there are two main things to be aware of that may give rise to a legal claim in Pennsylvania regarding storm water. First. if you are doing construction involving a large amount of soil disturbance or you are within proximity to a protected stream or waterway, you should determine whether you need a permit and soil erosion control plan. Second, if you are a homeowner or landowner in which you believe that storm or surface water is being diverted onto your property at a greater flow or intensity, then you may have a claim if you have resulting damages.
In the second instance, if you believe your property is being damaged, or there is a resulting injury to a person, then you should investigate the source of the problem. If there is recent construction of culverts or some drainage system, you should check with both your local government and PA Department of Environmental Protection. Find out what the project was and whether there needed to be a permit and/or erosion and soil control plan. Even if a permit or plan was not required, it still may be a violation of the Storm Water Management Act or Pennsylvania case law if the diversion of the surface water was negligently constructed or otherwise artificially channels water at an increased flow or velocity onto your property.
In such legal claims, there may be legal causes of action for: negligence, trespass, nuisance, or violations of the PA Storm Water Management Act or the PA Clean Streams Law. The Clean Streams Law (35 PS Section 691.1). The Clean Streams Law does allow for private citizen legal claims for pollution runoff into a waterway. It more often applies to PA Department of Environmental Protection or other governmental actions against polluters.
Usually, a legal claim involving an argument that there was a negligently constructed storm water drain or system or artificially channeled water runoff, requires use of an engineer. That engineer would need to inspect and possibly do a study to compile engineering findings to support the claims.