environmental assessment for the hog lake road improvement project

Ramona Hog Lake Road Improvement Project August 2011
along the roadway already occurs and dirt roads are known to produce fine sediment
in streams.
Proposed Action:
For the Proposed Action alternative, generalized impacts to jurisdictional drainages
would be expected as a result of equipment use, soil disturbance and construction of
the box culvert. These include an increase in erosion and sedimentation as well as
the potential for the discharge of hazardous materials. Channeling along the
roadway already occurs and dirt roads are known to produce fine sediment in
streams. Construction of the road could result in increased erosion and
sedimentation with disturbed soils and release hazardous materials from heavy
equipment into the streambed.
The proposed action includes the use of a culvert with sufficient size and capacity to
pass the flows and associated debris from a 25-year return interval storm. While the
Forest’s Land Management Plan requires sufficient size to accommodate a 50-year
storm, the project as designed is consistent with BIA standards. As this project is a
BIA proposal and the road will be brought into the BIA Transportation System, with
the BIA assuming responsibility for road maintenance, the Forest proposes to allow
a site specific amendment to the Forest Plan in order to accommodate the BIA.
Direct effects associated with implementation of the Proposed Action are estimated
as follows: for the blueline (BL), federal/ACOE 3,977 sf., state/CDFG 6,099 sf.;
drainage 1, federal /ACOE 170 sf., state/CDFG 170 sf; and drainage 14,
federal/ACOE 140 sf., state/CDFG 160 sf. Total impacts are estimated at 4,288 sf
(0.098 acres) federal/ACOE and 6,429 sf (0.148 acres) state/CDFG jurisdictional
area.
Indirect effects associated with implementation of the Proposed Action alternative
include impacts resulting from earthmoving or other construction activities that could
result in discharge of hazardous materials, silt, debris, or excessive erosion into
waters of the U.S. during Project construction.
Direct effects associated with the smaller BIA 25-year culvert design, rather than a
50-year design, could include debris plugging the culvert during storm events that
exceed the capacity of the 25-year culvert. Water could be forced out of the existing
channel and could erode the embankments or cause the loss of the road structure.
Indirect effects include that the loss of the road could cause access to the
Reservation to be limited to other, longer routes.
Frank Springer & Associates, Inc. Page 73 of 79 Environmental Assessment