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Special Topics
Submerged Aquatic Vegetation (SAV)
Submerged Aquatic Vegetation (SAV) is a unique aquatic resource that is regulated by the US Army Corps of Engineers and NC Department of Environment and Natural Resources. SAV provide nursery areas and sanctuary for aquatic fauna, food for aquatic fauna and waterfowl, bind shallow water sediments, aid in reducing wave turbulence, help remove nutrients from the water column, and add physical structure to the aquatic community. Generally, SAV do not occur in water depths of greater than two meters; however, local conditions may enable SAV to occur at greater depths.
There are three major halophilic (able to thrive in brackish or salt environments) SAV species in the sounds and estuaries of North Carolina: eelgrass (Zostera marina), widgeon grass (Ruppia maritima), and shoalgrass (Halodule wrightii). The major species encountered in freshwater sections of North Carolina sounds and estuaries include: tapegrass (Vallisneria americana), sago pondweed (Potamogeton pectinatus), southern naiad (Najas guadalupensis), clasping leaf pondweed (Potamogeton perfoliatus), and horned pondweed (Zanichellia palustris). Widgeon grass may also be found in freshwater.
Invasive species of SAV may also be observed. The most common invasive SAV in freshwater sections of North Carolina sounds and estuaries is Eurasian watermilfoil (Myriophyllum spicatum).
SAV Survey Protocols
SAV surveys may be necessary for highway projects in Coastal Area Management Act (CAMA) counties. The determination of the need for SAV surveys will be made on a project by project basis by the regulatory agencies.
SAV surveys will be conducted pursuant to the following protocols:
Scheduling
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The survey window for SAV is from the middle of June through the end of September. Late June or July is most appropriate.
Surveys will be conducted once prior to project construction and once within one year of completion.
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Survey Methodology
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Obtain preliminary design of the project.
Establish a survey transect perpendicular to the shoreline on the centerline of the project.
Establish additional survey transects at ten meter intervals on both sides of the centerline within the permanent and temporary construction zones.
Place a meter square grid, which is subdivided into 16, 25 cm x 25 cm subplots, at the start of the shoreline and identify SAV species, determine per cent cover and record SAV height and water depth.
Proceed along the transect and record SAV data as above at ten meter intervals.
The survey of the transect is complete when two sequential plots are void of SAV.
Surveys may be conducted by SCUBA, snorkeling, chest waders, or by boat. Selection of survey method will be based on local conditions, which include water quality conditions. It must be noted that some waters of North Carolina are dangerous and require dry suits and decontamination upon survey completion. All personnel must be aware of local conditions prior to survey initiation.
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Additional data collection that is necessary for the SAV survey includes:
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Transparency (Secchi disc)
Salinity
Tide height (lunar or wind)
Mean normal high water
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Report
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The Report will include all survey methodologies, and a description and rationalization of any deviations from the survey protocols.
Listing of species present
All data for each plot will be presented
Calculations of SAV coverage
Qualifications of investigators
Presentation of additional data (transparency, etc.)
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SAV Mitigation Protocols
The following protocol is the result of a multi-agency task group assembled to provide guidance to NCDOT for compensatory mitigation of impacts to Submerged Aquatic Vegetation (SAV) from NCDOT highway projects. This protocol will be implemented only after avoidance and minimization sequencing has been addressed.
The task group was formed for the following reasons
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SAV mitigation is not at all like traditional terrestrial wetland and stream mitigation.
All potential SAV sites are likely within public trust waters and not privately owned.
Traditional wetland and stream mitigation site searches would be ineffective for SAV mitigation.
Searches and identification of potential SAV restoration sites must be a coordinated effort with all agencies and organizations with a vested interest in this resource.
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- The protocol will apply to SAV impacts from NCDOT highway projects within all Coastal Area Management Act counties.
- NCDOT project specific commitments would include appropriate project design, construction techniques, and stormwater controls, which would minimize impacts to SAV communities, and, jurisdictional waters. Additionally, project aerial photography will include the proposed project study area, as well as, off-site locations to determine the potential for off-site restoration opportunities.
- Protocols: presented in order of preference (sequencing).
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- Restoration (restoration of damaged communities or creation of new communities). Restoration efforts must have multi-agency coordination in the identification, selection and implementation of the project. This may include "contracting" with an agency to develop, implement, and monitor the restoration project.
- On-site in kind. Restoration of SAV communities within the project corridor or directly adjacent to the project corridor. The corridor limits will be based on project engineering or construction limits.
- Off-site in kind, at a distance to be determined by agency coordination.
- Off-site out of kind. This would include restoration opportunities in locations that would be situated in different biogeographical locations. For example, mitigating freshwater impacts by restoring saltwater communities.
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- Enhancement (methods which would improve existing communities)
- Acquisition of upland buffers
- Retrofitting exiting stormwater controls where practicable
- Re-grading ditch channels
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- Non-Traditional Mitigation
- Large extent aerial photography on a periodic basis (time intervals to be determined).
- NCDOT photogrammetic mapping
- Provide funding and/or technical and photographic laboratory assistance for university SAV mapping programs.
- Provide funding and/or technical and photographic laboratory assistance for the multi-agency Submerged Aquatic Vegetation Work Group.
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- Water Quality surveys and research focused on SAV community integrity
- Customized SAV research
- Education/Outreach
- SAV information included on NCDOT's "North Carolina Coastal Boating Guide."
- Signage near marinas and public boat launch facilities, indicating the presence of sensitive SAV beds and the need for caution.
- Develop curriculum on SAV and other environmentally sensitive areas to be included in safe boating programs.
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- Restoration or enhancement of other environmentally sensitive areas, such as, oyster beds, and Essential Fish Habitat.
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The Submerged Aquatic Vegetation Task Group includes members from the following organizations: National Oceanographic and Atmospheric Administration, National Marine Fisheries Service, US Army Corps of Engineers, US fish and Wildlife Service, NC Department of Transportation, NC Division of Coastal Management, NC Division of Marine Fisheries, NC Wildlife Resources Commission, NC Division of Water Quality, and NC Coastal Federation.
NCDOT will coordinate with task group members for compensatory mitigation for SAV. Additionally, NCDOT will coordinate with the NC Ecosystem Enhancement Program, especially with regard to the EEP watershed plans, and NC Department of Agriculture with regard to the "Aquatic Weed Control Act of 1991."
Note: NCDOT will adhere to all regulations contained within the "Aquatic Weed Control Act of 1991" (Title 15A, Chapter 2, Subchapter 2G, of the NC Administrative Code). The Act prohibits the importation, sale, use, culture, collection, transportation, and distribution of noxious aquatic plants in North Carolina. SAV included in this Act are as follows: hydrilla (Hydrilla verticillata), Brazilian elodea, (Egeria densa), Eurasian watermilfoil (Myriophyllum spicatum), and brittleleaf naiad (Najas minor). The Act has significance with regard to freshwater SAV.
Essential Fish Habitat Assessment
An EFH Assessment is a written assessment of the effects of a proposed Federal action on EFH (50 CFR 600.920(e). Federal agencies must provide the National Marine Fisheries Service (NMFS) with an EFH Assessment for any action that may adversely affect EFH, except for those activities covered by a General Concurrence. NCDOT projects requiring federal permits or that involve federal funding are considered federal actions. An EFH Assessment must contain, 1) A description of the proposed action; 2) An analysis of the effects, including cumulative effects, of the proposed action on EFH and managed species; 3) The Federal agency's conclusions regarding the effects of the action on EFH and; 4) Proposed mitigation, if applicable (50 CFR 600.920(e)(3)). If appropriate, the EFH Assessment should also include the items listed at 50 CFR 600.920(e)(4). The level of detail in an EFH Assessment should be commensurate with the potential impacts to EFH (50 CFR 600.920(e)(2)).
The federal agency that provides the NMFS with an EFH assessment for NCDOT projects is the USACE. The NCDOT Natural Environment Unit Project Manager should incorporate the EFH Assessment into the NRTR when a project has the potential to affect habitat for any of the designated Essential Fish Habitat species.
Currently, there is no internal template for EFH Assessments. The best approach is to refer to the Guidance on Preparation of EFH Assessments and to make sure you have included all of the required information.
Final EFH Assessment Guidance
The attached links include an index of EFH species by water body and by county. Each index refers to a page on the accompanying spreadsheet that contains information on the presence of EFH species in a particular water body.
County Index
Water Body Index
County Index
The steps for conducting an EFH assessment are:
- Check the county index to see if the county you are working in is listed. Note that there are only 18 counties listed and all of them are coastal counties.
- If the county is listed as an EFH county, go to the appropriate page in the table to determine if the water body affected by your project is listed.
- If it is listed, the table will provide the names of species expected to be present in each water body. It will also provide the life cycle stages of each species for each water body. For example, the Currituck Sounds supports Eggs, Larval, Juvenile, and adult stages of Red Drum. But it only supports the juvenile stage of Gag Grouper.
- Confirm with the appropriate USACE representative that an EFH assessment is needed.
- Prepare the EFH assessment according to NMFS guidance.
- Send the EFH assessment to the USACE, NMFS, NCDWQ, NCWRC and the NCMFS.
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You may still need to do an assessment even if your project does not cross one of the listed water bodies. This is especially true if your project is in close proximity to a listed water or drains directly to a listed water. Once you determine that your project is not on the Index list, you should contact the appropriate USACE representative and tell them that you have reviewed the EFH county list of water bodies and have determined that your project does not affect a listed water. Based on that information, you do not intend to prepare an EFH assessment. They may request an assessment anyway. If they do, you will likely have to provide it. See step 5 from above for the preparation of the Assessment.
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