Humboldt Bay Pre-Project Eelgrass Checklist

Humboldt Bay supports California’s largest eelgrass population, yet people are often unaware of its distribution and the potential for impacting eelgrass habitat as a result of shoreline or in-water development, construction, and maintenance/repair activities.  Eelgrass is protected by state and federal law under a ‘no net loss’ policy. As such, eelgrass habitat should be avoided to the greatest extent possible. In cases where project-related activities cannot avoid eelgrass habitat entirely, efforts should be made first to design the project in a manner that minimizes impacts to eelgrass, and ultimately provide for mitigation of eelgrass habitat in cases where impacts are unavoidable. Eelgrass habitat may be impacted either directly or indirectly as a result of project activities, and those impacts may be temporary or permanent depending upon the nature of the activity. 
 
A number of measures can be employed to avoid and/or minimize potential project-related impacts to eelgrass and can be applied most effectively during initial project planning. Developing an understanding of eelgrass resources and the potential effects of a proposed project early on can save you time and money! The following checklist provides guidance for determining whether a project has the potential to affect eelgrass habitat and what to do about it.

 
Step 1 – Determine the Preliminary Area of Potential Effect (APE) for your proposed project:
 
Typically, the APE would include both the area of direct impact associated with the action for which a project applicant is seeking a permit, plus a surrounding buffer inclusive of the limits of potential construction and/or maintenance-related activities capable of impacting eelgrass habitat. It is important to ensure that the APE is sized and configured appropriately to capture the impact that would be anticipated as a result of the project. Prior to contacting either the Harbor District or the resource agencies (listed below) for further project-specific guidance, proceed to step 2 and complete the questionnaire. Additional resources that may be helpful in answering these questions are provided on the District’s website Additional Eelgrass Resources. Please consult the Baseline Eelgrass Distribution Map to assist in completing the questionnaire.
 
Step 2 – Complete the Pre-project Questionnaire:
New Projects-
Is the project located within 100 feet of previously mapped (known) eelgrass habitat?
 yes /  no
Will any construction or new operational traffic occur within the vicinity of existing eelgrass?
 yes /  no
Is any portion of the project located in an area with depths ranging from -10 to +4 feet?
 yes /  no
Does the project result in new cover, shading or other form of light reduction of open water areas ranging in depth from -10 to +4 feet?
 yes /  no
Is the project anticipated to affect wind or tidal circulation patterns within the bay?
 yes /  no
Could the project affect ambient water temperature or clarity?
 yes /  no
Does the project result in any placement of fill, including shoreline armor?
 yes /  no
Is the project anticipated to lead to an increase in boat traffic that could affect nearby eelgrass habitat through grounding, prop scarring, wake, or shading impacts?
 yes /  no
Maintenance/Repair Projects and Construction Activities-
Is project construction likely to increase turbidity? To what extent and for what duration?
 yes /  no
Will construction require the use of a barge or other vessel that may temporarily impact the bay floor (e.g. spud poles, anchoring, prop scarring, etc.) within known eelgrass habitat or within depths ranging from -10 to +4 feet?
 yes /  no
Will construction require the use of turbidity curtains in proximity to eelgrass habitat?
 yes /  no
Will project construction result in temporary shading from moored/anchored working vessel(s)?
 yes /  no
 
If you checked any of the yes boxes in the questionnaire, your project may have the potential to impact eelgrass habitat and you’ll need to proceed to step 3. If you answered no to all of the questions, please provide a copy of the completed questionnaire along with a brief project description and map depicting the proposed project location, suitable eelgrass depth range, and benchmark eelgrass distribution in the vicinity of the proposed project. Maps should be of an appropriate scale to clearly depict the preliminary/proposed APE boundary in relation to both existing and potential eelgrass resources provided in the HBECMP and associated webpage. 
 
Step 3-Conduct a Preliminary Eelgrass Survey:
 
If your project has the potential to impact eelgrass habitat, the next step is to conduct a preliminary/reconnaissance level eelgrass survey to inform further planning and permitting requirements.  A planning level survey may be conducted at any time of year (weather permitting) to support preliminary project planning; however, surveys conducted outside of the active growing season (May-September) could under-represent the full extent of eelgrass habitat that may be present in the vicinity of a proposed action. For this reason, preliminary surveys can be extremely useful in identifying if eelgrass habitat is present and therefore, whether further planning and design for minimization, avoidance, or mitigation is warranted; however, absence of eelgrass may not rule out the need to conduct a pre-construction survey if the preliminary survey is conducted outside of the active growing season.
 
If a preliminary eelgrass survey is conducted during the active growing season, and no eelgrass habitat is identified in the vicinity of a proposed action, then further eelgrass surveys may not be required upon the concurrence of the resource and permitting agencies.  This finding could result in a project applicant potentially avoiding the need to develop an eelgrass mitigation and monitoring program for a proposed action unnecessarily, saving both time and money.  If however, eelgrass is identified within or in close proximity to a preliminary project APE, then an applicant will likely need to develop an eelgrass mitigation and monitoring program in coordination with the resource agencies as a condition of approval with respect to acquiring state and/or federal permits for the proposed action.