Rossi Road Bridge Replacement (Notification of Lake or Streambed Alteration, No. EPIMS-NAP-59328-R3)

Rossi Road Bridge Replacement (Notification of Lake or Streambed Alteration, No. EPIMS-NAP-59328-R3)

The California Department of Fish and Wildlife (CDFW) has executed Lake and Streambed Alteration Agreement EPIMS Notification No. EPIMS-NAP-59328-R3, pursuant to Section 1602 of the Fish and Game Code, to the County of Napa. The Project is limited to removal of an existing roadway stream crossing, at Conn Creek on Rossi Road, including an approximately 165.5-foot-long by 22-foot-wide, 3,640 square-foot crossing structure, round culvert assembly, box culvert, concrete and earthen fill material, and road surface; and installation of a replacement 147.9-foot-long by 21.5-foot-wide, 3,180 square-foot crossing structure including a bridge and concrete wingwalls. The new bridge will be a free spanning unit, approximately 130 feet in length, constructed of a prefabricated modular steel frame supported by cast-in-drilled-hole piles at the abutments, with thirteen prefabricated modular panels measuring ten feet long by 13.75 feet wide constituting the deck of the bridge. Abutments will be placed outside the stream, above top-of-bank. Geo-composite drains will be installed on the outer edges of each wing wall. Additionally, approximately 60 feet of roadway on either side of the bridge will be resurfaced with asphalt concrete and new striping. Staging areas will be on paved roadways and/or bridge approaches. The Project will not add any non-native fill or new areas or volumes of rock slope protection (RSP) (e.g., rip rap), however it will reuse native fill or existing RSP, or replace existing RSP with new RSP, where needed. An existing 18-inch diameter reinforced concrete culvert located under the southwest side of the stream crossing will be retained. To protect water quality during bridge demolition, Conn Creek will be diverted through a 55-foot-long, 36-inch-diameter high-density polyethylene pipe installed with cofferdams. The Project will temporarily impact 0.015 acres (653 square feet) of riparian oak woodland from access and construction, and 0.020 acres (871 square feet) of the stream from dewatering, for a total of 0.035 acres and 66 linear feet of stream and riparian habitat. The Project will permanently impact 0.001 acres (43 square feet) of riparian oak woodland understory vegetation from the installation of the guardrails. The Project will not result in any new permanent shading impacts from the new bridge, as it will be smaller in area than the old bridge. The Project will restore and enhance 0.046 acres currently occupied by the existing structures, including the removal of hardscape features from 0.007 acres of stream habitat which will result in a net gain of 0.069 acres of natural stream habitat. No trees are planned for removal; however, trimming may be required for access. All temporary impacts will be restored, and the stream diversion will be completely removed following bridge installation.

St. Helena

Napa

San Francisco Bay Area

Napa