Much of the older urban development in the Raritan Basin was not designed to route runoff through stormwater management basins. Instead, the stormwater drainage systems collect runoff from dwelling roofs, yards, driveways and streets (i.e., on-street storm sewer grates) and discharge it directly into the nearest stream (i.e., at an outfall) with no treatment. River stretches with a high frequency of outfalls often suffer water quality degradation as well as streambed/bank scouring, especially during or after high flow events.
River/stream stretches with high frequencies of outfalls can suffer water quality degradation as well as streambed/bank scouring. Direct discharge outfalls should be prioritized for installation of BMPs to promote infiltration. There is no comprehensive inventory of outfalls in the Raritan.