Chapters 1 - U.S. Fish and Wildlife Service

Chapter 5
liquefaction, settlement, ground rupture, or lateral spreading. Therefore, no adverse effects
related to geology or soils are anticipated under this alternative.
Public Use
Existing soil and geological conditions on the site do not pose a hazard, nor do these conditions
adversely affect the function of the pathway that provides access for the public from the Refuge
office/visitor contact station to the observation deck or the observation deck itself. Therefore, the
facilities used in association with the existing public use program would not be impacted as a result
of the geological or soil conditions on the Refuge.
5.2.1.3 Effects on Mineral Resources
Continuing current management practices and public use programs on the Refuge would have no
effect on the ongoing oil extraction operation at Oil Island.
5.2.1.4 Effects to Agricultural Resources
Wildlife and Habitat Management
Lands identified as Prime Farmland occur immediately adjacent to the Refuge and these lands are
currently being farmed under the authority of the U.S. Navy. The continuation of wildlife and
habitat management activities and public use programs currently occurring on the Refuge would
have no effect on these ongoing farming operations. No effects to adjacent agricultural resources
are therefore anticipated under Alternative A.
5.2.1.5 Effects to Hydrology
Wildlife and Habitat Management
The primary management activities occurring on the Refuge that could have an effect on the
hydrology in and around the Refuge involves the repair and replacement of existing culverts that
facilitate tidal flows in and out of the restored wetland areas on the Refuge. These repairs are
intended to maintain, and in some cases restore, tidal circulation between the main marsh complex
and the restored subtidal areas of Forrestal, Case Road, 7 th Street, and Perimeter Ponds, as well
as improve tidal circulation within the marsh to levels that existed prior to culvert deterioration.
The activities would not result in any significant adverse changes to the hydrological conditions
within the Refuge. As described in Chapter 4, erosion resulting from tidal action and wind waves,
along with other factors, is occurring along the banks of Forrestal Pond, Case Road Pond, and the
mitigation channel to the west of the Bolsa Cell. No actions are proposed under Alternative A to
address this issue; therefore, erosion of the banks would be expected to continue under this
alternative.
Public Use
The existing public use program does not involve any activities that would impact hydrology within
or outside of the Refuge; therefore, there would be no effect to hydrology from the continuation of
the existing public use program on the Refuge.
5.2.1.6 Effects to Water Quality
Wildlife and Habitat Management
BMPs are currently implemented by Refuge staff as necessary during culvert maintenance
activities to minimize erosion and sedimentation into adjacent wetlands. These BMPs (e.g., fiber
rolls, silt fencing, cofferdams) are implemented during repairs to culverts, as well as other
maintenance activities occurring in areas upstream or adjacent to the marsh. The continued
implementation of these types of measures would minimize or avoid water quality impacts to the
coastal wetlands on the Refuge, as well as the adjacent Anaheim Bay. Monitoring and cleanup of
5-4 Seal Beach National Wildlife Refuge