State Route 58 Widening Project - Bakersfield Freeways

Chapter 4 Results: Biological Resources, Discussion of Impacts and Mitigation
to prevent obstructing the visual field of kit foxes near the roadway. Curbed medians
less than 10 inches in height and requiring landscaping will be planted with low level
vegetation (i.e., less than 6 inches) and will not require mowing (see measure
SJKF – 9).
No median barriers are currently proposed; however, if taller median barriers are
required in a later planning stage and for public safety, Caltrans-designed modified
median barrier type 60/S will be used. Caltrans type 60/S design has been approved
by USFWS (BO# 81420-2009-F-0752; USFWS 2009) and includes 9-inch radius
openings (9 inch high x 18 inch wide half circle openings) spaced every 150 feet to
allow passage by kit fox.
Low-height curbed medians or gapped median barriers are expected to reduce the
potential to disrupt north-south kit fox movement in the project area and reduce the
potential for vehicle strike, when implemented in conjunction with all project design
modifications, by allowing unlimited kit fox movement and providing kit fox with an
unobstructed line of sight.
• SJKF – 8 Maintain Open Movement Corridors
Existing kit fox movement corridors along all canals and railroad would be preserved
through the use of existing bridges. The toe-of-road fill and bridge support walls
should be maintained and new walls designed, no less than 20 feet from the centerline
of canal access roads and the centerline of railroads.
• SJKF – 9 Landscaping
Project landscaping will be designed to allow unobstructed visibility to kit fox and to
provide opportunities for movement across the roadway. Curbed median and roadside
landscaping will be planted in one of three alternative strategies: selecting plants that
do not exceed 6 inches tall at maturity, maintaining vegetation height so that it does
not exceed 6 inches and does not require mowing, and/or creating gaps no less than
4 feet wide every 12 feet in areas landscaped with trees and shrubs.
Low-height or gapped landscaping is expected to reduce the potential for vehicle
strike, when implemented in conjunction with all project design modifications, by
providing kit fox with an unobstructed line of sight.
State Route 58 Widening Project Biological Assessment 39