Draft Environmental Impact Report - California Off Highway Vehicle ...

3.5 Biological Resources
community is considered sensitive, the vernal pool community at the project site has been subject
to substantial disturbance (e.g., extensive soil excavation, OHV activity) and is therefore degraded
from its natural condition (e.g. vegetation is very sparse). Because historic and continuing
disturbance of this habitat has so substantially altered it, most changes proposed and envisioned
in the General Plan (e.g. an increase in visitors and OHV use) would not cause a substantial
increase in disturbance to the already‐disturbed conditions of the site. (Refer to impact 3.5‐3
below for a discussion of potential fill of vernal pools.) In fact, these changes would have the
potential to improve the condition of the vernal pool vegetation communities by concentrating
OHV activities in the developed use area of the SVRA which contains the least amount of this
habitat. Because the northern hardpan vernal pool habitat on the project site is already degraded
and because implementation of the General Plan, including construction and operation of the
headquarters facilities, is not anticipated to cause a substantial change in the condition of this
habitat, the potential for loss or disturbance of a sensitive vegetation community would be less
than significant.
Mitigation Measures: No mitigation is required.
IMPACT
3.5-3
Potential Fill of Waters of the U.S., Including Wetlands
Wetland delineations conducted in 2004, 2007, and 2010 identify approximately 26 acres of
jurisdictional waters of the U.S. at Clay Pit SVRA (AECOM 2010). Wetlands within the project site
boundaries include approximately 22.5 acres of vernal pools and 0.03 acre of emergent marsh,
described as the cattail vegetation community in the General Plan. Approximately 3 acres of other
waters of the U.S. consist of approximately 1.25 acres of canal, 0.5 acre of intermittent drainage
channel, and a 0.75‐acre pond. There are also 0.6 acre of ditch and 0.05 acre of ephemeral
drainage. Characterization and acreage of all water features were confirmed during the USACE
verification process for the wetland delineation, and a jurisdictional determination for the SVRA
was obtained in March 2011; consequently, these features are considered waters of the U.S.
subject to USACE jurisdiction under Section 404 of the CWA.
Implementation of the General Plan could cause direct and indirect impacts on these jurisdictional
features. Land use areas in the General Plan are defined such that most facilities would be
constructed in areas that do not contain jurisdictional wetlands and other waters of the U.S. In
addition, Water Guideline 1.1 in the General Plan stipulates that these features be avoided to the
extent feasible. However, the possibility remains that construction of facilities (such as water
crossings or 4x4 facilities) and habitat enhancement activities (such as restoration of eroded
features) could result in the fill of jurisdictional features. Implementation of Water Guideline 2.1,
and Soils Guideline 1.3 in the General Plan would minimize potential impacts on waters of the U.S.,
including wetlands. In particular, if fill of these features were unavoidable, a CWA Section 404
permit would be obtained from USACE, CWA Section 401 certification would be obtained from the
Clay Pit State Vehicular Recreation Area
February2012 3.5-10 Draft EIR