Ground Disturbance in Vernal Pools

If the intent of a Proposed Restoration Project is to improve habitat for Covered Species of vernal pool Branchiopoda (e.g., enlarge, deepen, repair, or otherwise modify suitable aquatic habitat), and would require ground disturbance in suitable habitat, the Project Proponent will submit detailed project design information for review and approval by the USFWS Field Office in the ESA Section 7(a)(2) Review Form. Any grounddisturbing activities within 25 feet of the edge of the pool will be conducted consistent with a plan reviewed and approved by the USFWS Field Office and will be conducted during the dry season. The following measures may also apply and should be considered during development of the plan:

a. If inoculum from an existing site will be used for restoration/enhancement, the plan will identify any proposed donor pools and include documentation that the pools are free of versatile fairy shrimp (Branchinecta lindahli). No more than 5% of the basin area of any donor pool will be used for collection of inoculum.

b. Restoration plans that include grading or regrading of vernal pools will include all final specifications and topographic-based grading, planting, and watering plans for the vernal pools, watersheds, and surrounding uplands (including adjacent mima mounds) at the restoration sites. The grading plans will also show the watersheds of extant vernal pools, and overflow pathways that hydrologically connect the restored pools in a way that mimics natural vernal pool complex topography/hydrology.

c. Restoration plans that include grading or regrading of vernal pools will include a hydraulic analysis that shows each proposed vernal pool and its watershed, and a calculation showing vernal-pool-to-watershed ratio. The vernal-pool-to-watershed ratio will be similar to extant pools closest to the restoration area.

d. Prior to ground disturbance in suitable habitat, loose substrate, which may include cysts of Branchiopoda, will be collected from the pool area to be disturbed by vacuum and stored in dry conditions until grading is complete. All collected substrate that may contain cysts of Branchiopoda will be temporarily stockpiled onsite, maintained in ambient conditions, and protected from rain and wind for subsequent redeposition in restored vernal pool areas.

e. Topsoil will be removed and stockpiled separately.

f. Disturbance of the less permeable, hardpan or claypan soil layer that often helps form vernal pools will be minimized. If the less permeable layer must be removed, it will be stockpiled separately.

g. When grading is complete, layers will be replaced in the reverse of the order in which they were removed; replacement will begin with subsoil, followed by the less permeable layer, then topsoil, and then loose material collected by vacuum. Subsoil and less permeable layers should each be compacted following placement to decrease permeability of restored or modified suitable habitat.

h. Any groundwater encountered in excavations within vernal pool habitats during dry season work will be pumped into a water truck and discharged offsite or discharged in areas onsite where it will not migrate back into these habitats.

i. Not to exceed the self-imposed take limit of no more than 10% temporary habitat loss per occupied pool. However, some vernal pools are so degraded that extensive enhancement activities are needed. Thus, this limit can be exceeded for those projects where the sole purpose of the impact is to restore ecological function to the vernal pool, with agreement of the respective USFWS FO, via the ESA Section 7(a)(2) Review Form Process.