Stormwater, Erosion & Flooding

The number of calls the Township receives about stormwater issues has increased considerably over the years. This trend corresponds with a report issued in 2019 by the Delaware Valley Regional Planning Commission (DVRPC), titled “Municipal Management in a Changing Climate.” While the report indicates that average precipitation has not changed significantly (a slight upward trend of about two inches per century), it reports that there has been a notable uptick in storm intensity.

Each time we receive a complaint about stormwater, erosion, or flooding, we investigate the situation. In a few cases, a drainage facility has clogged or isn’t operating as intended. However, in most cases, there is nothing actually wrong. It is simply that more stormwater is generated by these more intense storms, especially when the ground is saturated by previous storms. In such cases, the runoff is considered historically consistent and no one upstream is responsible for damage to downslope properties. It is only when something upslope changed in a way that altered drainage patterns or caused increases in drainage that an entity could be found responsible for downslope damage (or in cases where a facility has failed).

In the case of Township roads, many of the design standards have changed since most of our roads were constructed, and existing piping facilities were not designed to accommodate today's runoff rates. These facilities are “grand-parented” and the Township is not required to upgrade them to current standards (this same concept is applied to private properties with existing facilities that were designed per historic standards). However, all new improvements and replacements of deteriorated facilities are designed to current standards to the extent physically possible. We recognize that recent weather trends have been challenging and we will investigate drainage concerns to determine whether there is an upslope cause or whether the drainage facility that is operating as originally designed.