Summary

The U.S. Bureau of Indian Affairs (BIA) is requesting §401 CWA Water Quality Certification from the Environmental Protection Agency. The §401 CWA Water Quality Certification will authorize maintenance activities on the South Fork of the Humboldt River to replace the Indian Bench Bridge.

Dates

Written Comments must be received on or before June 22, 2020.

For Further Information Contact

Leana Rosetti (rosetti.leana@epa.gov)
Wetlands Section (WTR-2-2)
U.S. Environmental Protection Agency
75 Hawthorne St.
San Francisco, CA 94105
(415) 972-3070

Supplemental Information

The BIA is proposing to replace the Indian Bench Bridge that was damaged beyond repair by flooding in 1995 to create a permanent crossing of the South Fork of the Humboldt River. The work includes removing the bridge remnants. The crossing will be constructed with eight (8) side-by-side 3' h x 99' l x 4' w precast concrete box girders, resting on concrete beam abutments supported by steel piles, including concrete wing walls and rail bank protecting the abutments. Less than 3 cy of structural backfill, less than 3 cy of rip rap, and less than 10 lbs of steel will be deposited below the River OHWM to install the rail bank protection. Approximately 13 cy of concrete will be placed in wetlands to build the wingwalls. One steel test pile will be driven within wetlands at each abutment. Three (3) overhead utility lines/poles will be relocated within the jurisdictional wetlands. Approach roads on both sides of the River, within wetlands, will be constructed including 650 cy of borrow and approximately 500 lf of new culverts. The excavation, deposition and/or placement of fill, rip rap, steel, and concrete into Waters requires authorization from the Corps and a 401 Water Quality Certification from EPA.

The total potential jurisdictional acreage within the bridge study area is 4.14 ac. Approximately 300 linear feet of stream bank, 0.82 ac of palustrine, emergent, scrub-shrub wetlands and 0.0002 ac of the perennial stream channel will be permanently impacted. To construct the bridge approximately 0.08 ac of wetlands and 0.04 ac within the OHWM will be temporarily impacted by the project.

Permanent impacts will result from excavation, installing scour protection, utility relocations, and from construction equipment crossing in the River channel. Construction has the potential to impact birds protected under MBTA, although tree/shrub removal will be required to take place before or after the breeding season. There would be a temporary loss of habitat and the displacement of resident wildlife and possibly injury or death to smaller animals. Aquatic species will be affected by a temporary limitations on movement, increased sediment in the River, and noise-related disturbances.

The BIA proposes to mitigate for the project by contributing to ongoing environmental improvement projects at the South Fork of the Humboldt River within the South Fork State Recreation Area (SFSRA), as well as to provide a limited number of willow pole plantings at the bridge site. The Nevada Division of Forestry (NDF) is continuing their 8-year efforts toward the South Fork Stabilization and Meadow Rehabilitation project. As a component of this long term project, The BIA will contribute funds for the execution of tasks that will enhance riverine and meadow functions at the site.