This alternative will have no planned construction; US 101 will continue on its existing alignment. Regular maintenance and operations will continue, with emergency restoration projects as needed. Current annual maintenance costs of $2 million with a projected cost of approximately $26 million by 2034. Engineering solutions, such as retaining walls, have not been able to provide long-term stability and will continue to be necessary to provide an adequate highway facility. As the landslide moves slowly, the road will require costly repairs and maintenance with potential environmental impacts including old-growth redwood impacts associated with minor retreats to keep the roadway open. A future slide might occur that is deep enough and large enough that it could result in a major failure of the roadway and complete closure of the roadway for an unknown period of time. A major failure would have economic impacts and require a significant detour as outlined in the Economic Impact Study. Some potential options closest to the existing alignment include a retreat upslope that could require taking more than 100 old-growth trees. For a more detailed explanation, please refer to page 15 of the Engineered Feasibility Study, available in the Document Library.

On the map, the red line indicates the current LCG alignment.

(Includes 2,425 foot tunnel)

Travel Time Added (minutes)

Added Time: 1.0 min

New Construction

Construction Length: 3.2 miles

Structures:

• Culverts > 36”: 9
• Tunnel: Yes
• Bridges: 1

Length Within Parks: 0.8 miles

Construction Footprint: 80 acres

Construction Schedule: 3 years

Watershed Crossings

Wilson Creek: 1

Mill Creek: 0

Construction Cost in 2016 $ (Millions)

$672M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 57 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 1.5 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the pink area with yellow border indicates the position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

Travel Time Added (minutes)

Added Time: 0.8 min

New Construction

Construction Length: 3.2 miles

Structures:

• Culverts > 36”: 10
• Tunnel: No
• Bridges: 2

Length Within Parks: 0.6 miles

Construction Footprint: 85 acres

Construction Schedule: 2 years

Watershed Crossings

Wilson Creek: 2

Mill Creek: 0

Construction Cost in 2016 $ (Millions)

$240M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 61 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 3 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

(5,600 foot tunnel)

Travel Time Added (minutes)

Added Time: 1.0 min

New Construction

Construction Length: 1.3 miles

Structures:

• Culverts > 36”: N/A
• Tunnel: Yes
• Bridges: N/A

Length Within Parks: N/A miles

Construction Footprint: 4.5 acres

Construction Schedule: 6.5 years

Watershed Crossings

Wilson Creek: N/A

Mill Creek: N/A

Construction Cost in 2016 $ (Millions)

$1,062M

Existing Habitat Type

Coastal scrub/grassland /spruce: 2 acres

Riparian: 0 acres

Clear cut: 0 acres

Young Redwood Forest: 0 acres

Mature Redwood Forest: 1 acre

Old Growth Redwood Forest: 1.5 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the pink area with yellow border indicates the position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

Travel Time Added (minutes)

Added Time: 2.2 min

New Construction

Construction Length: 1.3 miles

Structures:

• Walls > 1
• Tunnel: No
• Bridges: N/A

Length Within Parks: 2.2 miles

Construction Footprint: 47 acres

Construction Schedule: 3.5 years

Watershed Crossings

Wilson Creek: N/A

Mill Creek: N/A

Construction Cost in 2016 $ (Millions)

$220M

Existing Habitat Type

Coastal scrub/grassland /spruce: 28 acres

Riparian: 0 acres

Clear cut: 0 acres

Young Redwood Forest: 0 acres

Mature Redwood Forest: 18 acres

Old Growth Redwood Forest: 1 acre

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the pink area with yellow border indicates the position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

Travel Time Added (minutes)

Added Time: 1.1 min

New Construction

Construction Length: 1.3 miles

Structures:

• Walls > 8
• Tunnel: No
• Bridges: N/A

Length Within Parks: 1.1 miles

Construction Footprint: 20 acres

Construction Schedule: 3.5 years

Watershed Crossings

Wilson Creek: N/A

Mill Creek: N/A

Construction Cost in 2016 $ (Millions)

$120M

Existing Habitat Type

Coastal scrub/grassland /spruce: 10 acres

Riparian: 0 acres

Clear cut: 0 acres

Young Redwood Forest: 0 acres

Mature Redwood Forest: 10 acres

Old Growth Redwood Forest: 0 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the pink area with yellow border indicates the position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

The Project stakeholders and the project development team agreed in late 2018 to eliminate the three C alternatives from further study for the following reasons:

1. The Expert Risk Assessment estimated that these alternatives have a high risk of geotechnical failure. The risk of building these alignments is higher than staying on the current alignment and making improvements as alternative X would do.
2. The C alternatives have no unique environmental benefits.
3. The C alternatives are high cost and have high environmental impacts.

(Includes 1,680 foot tunnel)

Travel Time Added (minutes)

Added Time: 1.7 min

New Construction

Construction Length: 7.8 miles

Structures:

• Culverts > 36”: 19
• Tunnel: Yes
• Bridges: 4

Length Within Parks: 3.2 miles

Construction Footprint: 245 acres

Construction Schedule: 3 years

Watershed Crossings

Wilson Creek: 6

Mill Creek: 3

Construction Cost in 2016 $ (Millions)

$798M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 200 acres

Mature Redwood Forest: 23 acres

Old Growth Redwood Forest: 0 acres




On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the pink area with yellow border indicates the position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

The Project stakeholders and the project development team agreed in late 2018 to eliminate the three C alternatives from further study for the following reasons:

1. The Expert Risk Assessment estimated that these alternatives have a high risk of geotechnical failure. The risk of building these alignments is higher than staying on the current alignment and making improvements as alternative X would do.
2. The C alternatives have no unique environmental benefits.
3. The C alternatives are high cost and have high environmental impacts.

(Includes 1,680 foot tunnel)

Travel Time Added (minutes)

Added Time: 1.5 min

New Construction

Construction Length: 8.6 miles

Structures:

• Culverts > 36”: 14
• Tunnel: Yes
• Bridges: 5

Length Within Parks: 4.0 miles

Construction Footprint: 265 acres

Construction Schedule: 4 years

Watershed Crossings

Wilson Creek: 6

Mill Creek: 4

Construction Cost in 2016 $ (Millions)

$848M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 200 acres

Mature Redwood Forest: 43 acres

Old Growth Redwood Forest: 0 acres




On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the pink area with yellow border indicates the position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

The Project stakeholders and the project development team agreed in late 2018 to eliminate the three C alternatives from further study for the following reasons:

1. The Expert Risk Assessment estimated that these alternatives have a high risk of geotechnical failure. The risk of building these alignments is higher than staying on the current alignment and making improvements as alternative X would do.
2. The C alternatives have no unique environmental benefits.
3. The C alternatives are high cost and have high environmental impacts.

(Includes 1,680 foot tunnel)

Travel Time Added (minutes)

Added Time: 2.6 min

New Construction

Construction Length: 11.7 miles

Structures:

• Culverts > 36”: 21
• Tunnel: Yes
• Bridges: 11

Length Within Parks: 7.0 miles

Construction Footprint: 330 acres

Construction Schedule: 4 years

Watershed Crossings

Wilson Creek: 6

Mill Creek: 10

Construction Cost in 2016 $ (Millions)

$1,003M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 216 acres

Mature Redwood Forest: 93 acres

Old Growth Redwood Forest: 0 acres




On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the pink area with yellow border indicates the position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.