Stormwater treatment facilities are not jurisdictional wetlands; however, stormwater to wetland conversion can occur if they are not maintained according to an approved management plan. As long as they are maintained according to the plan, and drainage functions as designed, they remain non-jurisdictional.
Impacts of Latest Stormwater Regulations
Increasingly, developers, land owners, and facility managers are subject to new stormwater requirements. More projects will be required to build biotreatment basins under the State Water Resources Control Board clause e.12 of the Phase II Small MS4 General Permit starting July 1, 2015. The State Board recently passed the Industrial General Permit which also goes into effect in July.
The result of these new regulations is likely to push many facility owners to build advanced Best Management Practices (BMPs) – structural stormwater facilities such as biotreatment basins, media filters, and bioswales. More and more stormwater facilities are being built to improve water quality and ease pressures on aging infrastructure.
Is it a Wetland or a Stormwater Facility?
Sometimes stormwater facilities and wetlands are difficult to tell apart. They are both usually low-lying, soggy places with similar plants. However, legally, they are quite different. Wetlands are subject to a myriad of legal protections including the Federal Clean Water Act (Section 404/401) and California’s Porter Cologne Water Quality Control Act. Because of this, any earthwork in (and often near) a wetland will trigger the need for numerous permits. Stormwater facilities, on the other hand, are exempt from these permits in most cases.
When it comes to determining if a feature is a wetland or a stormwater facility, maintenance is the key. Regularly maintained stormwater facilities are much less likely to be deemed wetlands. Furthermore, the maintenance activity itself is exempt from wetland permits. Landowners and developers should take care to keep construction plans for stormwater facilities in order to show the intended purpose of the facility was for stormwater management and it is not a ‘naturally’ occurring wetland. Facilities that are unmaintained, abandoned, or forgotten are much more likely to be deemed wetlands in the future.
A Look at the Regulations
At the Federal level, the Clean Water Act provides for an exemption from permits “for the purpose of construction or maintenance of farm or stock ponds or irrigation ditches, or the maintenance of drainage ditches.” In addition, the U.S. Army Corps of Engineers (Corps), in Nationwide Permit 43, state that “stormwater management facilities that are determined to be waste treatment systems under 33 CFR 328.3(a)(8) are not waters of the U.S., and maintenance of these waste treatment systems generally does not require a section 404 permit.”
In California, the State Board’s Resolution No. 94-102: Policy on the Use of Constructed Wetlands for Urban Runoff Pollution Control states, “Wetland systems constructed to treat urban runoff are intended, in part, to meet Clean Water Act requirement to reduce pollutants in urban runoff discharges … As treatment systems, constructed wetlands operated and maintained according to this policy will not be waters of the U.S. Constructed wetlands that are not operated and maintained according to terms of this policy and the approved management plan (required by Provision 7) may forfeit the designation of ‘treatment system’.”
Maintain Your Facility … and Your Records
Many municipalities now require an approved stormwater facilities maintenance plan and an annual report for all new stormwater facilities. Provided the maintenance plan is followed, stormwater facilities should not convert to a jurisdictional wetland. Owners can further protect themselves by completing and submitting annual reports to their local county or city.
Maintenance plan and reporting templates and checklists are available from many municipalities (see additional resources links below). Typical maintenance activities include:
- Removing trash and debris that might obstruct outfalls/inlets;
- Observe the facility drains after a rain event;
- Inspect for erosion or sediment accumulation;
- Remove and replace dead vegetation; and
- Maintain vegetation and irrigation.
A word of caution about maintenance of basins, sedimentation ponds, ditches, and constructed wetlands: check with trusted qualified biologist regarding wildlife presence before you embark on maintenance of your water treatment facilities, including vegetation or heavy sediment removal. Federal and/or State protected species could be present and if impacted, may result in violations of applicable laws.
- Clean Water Act Section 404
- Corps Nationwide Permit 43
- State Water Board Resolution No. 94-102: Policy on the Use of Constructed Wetlands for Urban Runoff Pollution Control
Maintenance Templates & Guidance
- San Mateo Countywide C.3 Stormwater Technical Guidance (Appendix G)
- Contra Costa County Stormwater C.3 Guidebook (Example Maintenance Plans & Fact Sheets)
- Alameda County C.3 Guidance Table (Appendix H)
- Bay Area Stormwater Management Agencies Association Post-Construction Manual for Marin, Sonoma, Napa, and Solano Counties (Chapter 5)