A stormwater basin is a structure used to detain and treat stormwater runoff. Basins help prevent flooding, especially flash flooding, along New Jersey’s watercourses. Stormwater basins are generally proposed as part of a larger residential or commercial project which has triggered compliance with the Stormwater Management rules at N.J.A.C. 7:8.
Stormwater basin construction, repair or reconstruction may result in disturbances to “special areas” regulated by the Department and may require multiple permits from the Division of Land Use Regulation prior to site preparation or construction. The presence or absence of special areas can be rudimentarily determined using the Department’s online mapping service, NJ-GeoWeb. Special areas within your project site may also affect the type of authorization required. Therefore, it is important to closely examine a proposed project relative to the sensitive areas which may be impacted.
The above tabs provide additional information on permit requirements relating to stormwater basin construction, repair, and/or reconstruction. For impacts to streams, rivers, lakes, ponds, flood plains, flood ways, riparian zones, please see the "Flood Hazard" tab. For impacts to special coastal areas, please see the "Coastal" tab. For impacts to Freshwater Wetlands, see the "Freshwater Wetlands" tab. Information on Tidelands can be found by selecting the "Tidelands" tab.
Constructing a new Basin
There are no Freshwater Wetlands General Permits for the construction of a stormwater basin (basin) within freshwater wetlands and/or State open waters. If the basin will be located in transition areas only, the project may be eligible for a “Transition Area Special Activity Waiver” (SAW) for “Stormwater Management”. In order to qualify, the applicant would have to demonstrate that there is no other feasible location or configuration for the basin that would minimize impacts to the transition area. In the alternative, the basin could be constructed within a transition area through the use of a “Transition Area Averaging Plan”.
If the basin will disturb freshwater wetlands or State open waters, or it cannot comply with the SAW requirements, a Freshwater Wetlands Individual Permit (IP) would be required. An IP application would need to include a description as to why the basin cannot be constructed outside of regulated areas.
Maintaining a Previously Constructed Basin
Before determining if a permit is necessary from the Division for maintenance, it is important to determine if the area within the basin would be considered regulated wetlands. Basins previously constructed in wetlands or on streams would likely be regulated under the FWPA. Those basins constructed within uplands where hydrophytic vegetation has developed (either intentionally or unintentionally) within the basin, may or may not be considered regulated. This determination would be dependent on other parameters such as the presence of hydric soils within the basin.
If an area within a basin is considered regulated under the FWPA, an applicant can clean or maintain the basin after obtaining a Freshwater Wetlands General Permit 1 (GP1) – “Maintenance and repair of existing features”. This allows for the maintenance within the basin as long as the activities don’t expand, widen, or deepen the basin beyond the original design depth. The permit is active for 5 years with an optional extension for 5 more years. This allows for up to 10 years of basin maintenance under a single permit.
When submitting for a GP1 for stormwater basin maintenance, the Department has 30 days from the day it is determined to be administratively complete in which to issue a decision as to whether the activities are not authorized under a GP1, or that it may be authorized but will require a full application review. If the applicant does not receive a notification of either decision than the application is automatically approved. Please see the appropriate section of the Freshwater Wetlands Protection Act Rules, 7:7A-5.1 for more information.
The construction of a detention basin in regulated areas requires authorization by the Department, However, if the project is regulated pursuant to the Coastal Zone Management Rules at N.J.A.C. 7:7, then no separate flood hazard area approval is required. In these instances, the applicant need only submit a report and plans demonstrating compliance with the Flood Hazard Area Control Act Rules at N.J.A.C. 7:13 as part of the coastal permit application. However, for projects in areas regulated under the Flood Hazard Area Control Act Rules, a flood hazard area permit is required.
General permit-by-certification 11 at N.J.A.C. 7:13-8.11 authorizes the maintenance of existing stormwater management structures, including basins. Work is restricted only to what is necessary for the maintenance of the structure and cannot result in the expansion or modification of the structure. Activities are limited to removal of accumulated sediment, debris, or nuisance vegetation, stabilization of an eroded structure, or the repair and/or in-kind maintenance of the basin. Activities cannot increase flooding and riparian zone disturbance is generally prohibited.
If the project does not qualify for general permit-by-certification 11,, then the project may be authorized under a flood hazard area individual permit pursuant to N.J.A.C. 7:13-10, 11, and 12. N.J.A.C. 7:13-12.2 discusses the requirements for stormwater management and specific design and construction standards that apply to any regulated activity associated with a major development, as defined in the Stormwater Management rules at N.J.A.C. 7:8-1.2. Stormwater management requirements are applicable to basins located within or discharging within a flood hazard area as well as in other regulated areas.
A verification under N.J.A.C. 7:13-5 may also be required to conduct the detention basin activities.
The Stormwater Management rules at N.J.A.C. 7:8 specify stormwater management standards that are mandatory for new major development. The New Jersey Stormwater Best Management Practices Manual (BMP manual) provides guidance to address the standards and is available at www.njstormwater.org/
Pursuant to the Coastal Zone Management rules at N.J.A.C. 7:7, a stormwater management facility is a facility which receives, stores, conveys, or discharges stormwater runoff and is designed in accordance with all applicable local, county, and State regulations. A stormwater management facility may be a retention or detention basin, infiltration structure, grassed swale, filter fabric, rip-rap channel, and/or stormwater outfall.
The “Jurisdiction” tab of the "Coastal Areas" webpage can help you determine which areas of your site may be regulated. Please be advised, there are no exemptions, Permits-by-rule, General Permits-by-Certification, or General Permits available for stormwater basin/stormwater management facility projects within coastal areas. Therefore, this work generally requires receipt of an Individual Permit.
Tidelands, also known as riparian lands, are all those lands now or formerly flowed by the mean high tide of a natural waterway; that is to say any land that is currently or was previously covered by tidal waters. The State of New Jersey, and therefore the people of New Jersey, owns all Tidelands except for those to which it has already sold its interest in the form of a riparian grant. It is important to note that the State generally does not own artificial waterways such as lagoons however, the State does claim those lands within a lagoon that were flowed by the mean high tide of a natural waterway which existed prior to the creation of the lagoon.
Detention basins that are proposed in an area that is currently landward of the mean high water line but was, at some point, flowed by the tide may require a tidelands grant.
A riparian grant, or tidelands grant, is a deed from the State of New Jersey selling its tidelands. Tidelands grants are generally only issued for lands that have already been filled in and are no longer flowed by the tide.
For more information on tidelands instruments, please see the tidelands section of this website.
For information and instruction on how to determine whether you are in an area that may require either a license or a grant, or for information how to apply for Tideland instruments please see the "Before you Build, Before you Buy" webpage.