A clear creek winding through a bright-green mountain meadow, with low shrubs in the foreground, dense conifer forest behind and a bare rocky peak under white clouds.

Representative photo — not the project site.

Forest road realignment

Humbug Summit Road Realignment and Reroute

Surveys of 2.14 miles of Forest Service roads, including 10 stream crossing sites, and plans to move Humbug Summit Road out of Willow Creek Meadow.

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The project

The Humbug Summit Road Realignment is a planned reroute within the Upper Butte Creek Forest Health Project in Lassen National Forest. It would move a stretch of Humbug Summit Road out of Willow Creek Meadow to support meadow and stream restoration on Willow Creek.

On a Lassen National Forest project planned with the Butte County RCD, American Engineering prepared the surveys and road relocation plans for a watershed consulting firm.

Willow Creek Meadow lies at the base of Humbug Summit in the Almanor Ranger District. Humbug Summit Road, a lightly used route from the Skyway to the Almanor Basin, bisects the meadow; Butte County Public Works and the Forest Service have maintained it together under a cooperative agreement dating from 1973. The Butte County Resource Conservation District (RCD) helps the forest plan the wider project and leads its state environmental review.

The RCD's draft Negative Declaration says the road and stream are "in hydrological conflict." At the meadow crossing site, "overtoppings, headcuts, clogged culverts and minor washouts must be corrected each year." Historic logging and grazing have also affected the meadow, and the 2021 Dixie Fire burned much of its watershed at high severity.

The project area holds most of the headwaters of Butte Creek, which the draft document calls "the best remaining stronghold" of threatened Central Valley spring-run Chinook salmon. The RCD's goals for the meadow put its water table and wet meadow–riparian vegetation first, with stable stream channels for habitat diversity.

Scope

Our scope

American Engineering's work, grouped by phase:

  1. Survey the roads and crossings

    • Topographic surveys of 2.14 miles of Forest Service roads, including 10 stream crossing sites

    The measured base for road and crossing design. See topographic surveying.

  2. Size the culverts

    • Culvert sizing calculations

    Estimating the flow a stream must pass and checking a culvert can carry it. See stormwater calculations.

  3. Plan the reroute

    • Plans to decommission a segment of Humbug Summit Road that bisects a habitat-sensitive wetland meadow
    • Plans to relocate Humbug Summit Road out of the influence of Willow Creek and the wetland meadow
    • Plans upgrading two other Forest Service roads
    • Stream crossings

    Drawings for the road work and crossings: see improvement plans and grading plans.

  4. Estimate the cost

    • Engineer's estimate of probable cost

    The plan quantities, priced to give a probable cost for the work.

Technical highlights

How the work fits together

How the planned reroute takes the road out of the meadow, and what goes into sizing a culvert at a stream crossing.

Moving the road out of the meadow

Moving roads out of areas prone to flooding is a Forest Service road-remediation practice. The RCD describes a realignment that would use portions of existing roads, upgraded, plus a short segment of new construction, built to Butte County Public Works standards. The draft Negative Declaration says a 0.40-mile stretch through the meadow would then be decommissioned, and the east–west trip would grow from 11.2 to 12.2 miles.

The road through the meadow, today and as planned (plan view)

Illustrative diagram — not to scale

Today

Today: Humbug Summit Road runs through Willow Creek Meadow Plan view with north at the top. Willow Creek runs west to east along a green meadow, and a small tributary flows north into it. The road runs through the meadow and crosses the tributary at a crossing ringed in red, the problem site. Two existing roads run south from the west and east ends of the meadow, outside it. Shapes and positions are illustrative. Willow CreekMeadowN123
  1. Humbug Summit Road bisects Willow Creek Meadow.
  2. At the meadow crossing, overtopping, headcuts, clogged culverts and minor washouts need repair every year.
  3. Existing roads on the slopes outside the meadow.

Planned

Planned: the road rerouted around the meadow on upgraded and new segments The same plan view. The road segment inside the meadow is shown dashed, to be decommissioned. A thick navy route leaves the road at the west end of the meadow and follows part of one existing road south, crosses east on a short dashed segment of new construction that passes south of the tributary's head, and returns north on part of a second existing road to rejoin the road at the east end of the meadow, without crossing the meadow or its stream complex. The new segment is the shortest of the three legs. Shapes and positions are illustrative. Willow CreekMeadowN1223
  1. The meadow segment would be decommissioned and returned to meadow and riparian habitat.
  2. Portions of existing roads would be upgraded to carry the route.
  3. A short segment of new construction would link them, avoiding the meadow and its stream complex.
Schematic simplified from the public reroute map in the draft Negative Declaration. Road shapes, lengths and positions are illustrative, not survey data or project drawings.

What goes into sizing a culvert

A survey supplies the channel profile, the inlet and outlet inverts (pipe bottom elevations) and the road fill. Hydrology supplies the drainage area above the crossing and an estimated design flow. The engineer then checks that a culvert passes that flow with the headwater below its crown, leaving room for the wood and sediment streams carry.

Inputs to culvert sizing at a stream crossing (profile along the stream)

Illustrative diagram — not to scale

Survey data and hydrology feed the sizing of a culvert under a road fill A profile along a stream flowing left to right under a road fill. A culvert lies on the streambed at its natural grade, with rock at the outlet. Navy dots mark surveyed points along the channel, at the inlet and outlet inverts and on the road. An inset shows the drainage area above the crossing, with an arrow for the design flow. At the inlet, the headwater depth HW is less than the culvert diameter D, and a floating log and a gravel wedge show the wood and sediment that must pass. Illustrative only. Drainage areaDesign flowHWDRoad fill12345
  1. Navy dots: survey points on the channel profile, the inlet and outlet inverts, and the road.
  2. The drainage area above the crossing sets the estimated design flow.
  3. At the design flow, the headwater (HW) at the inlet stays below the culvert's diameter (D).
  4. Wood and sediment must pass as well as water.
  5. Laid at streambed grade, with rock at the outlet against scour.
A generic stream crossing in profile. Illustrative only: not this project's culverts, sizes or design criteria.

Engineering considerations on mountain road reroutes

  • Surveying under forest canopy

    Tree canopy and steep terrain weaken satellite (GNSS) signals, so forest road surveys often pair GNSS control with total-station or level work, within short high-elevation field seasons.

  • Design flows without stream gauges

    Mountain streams rarely have gauges, so peak flows are estimated from drainage area with runoff, regional regression or flow-transference methods, with snowmelt and rain-on-snow in mind.

  • Wood and sediment

    A crossing must pass the wood and sediment a storm brings as well as the water, so sizing and inlet design allow for debris. Burned watersheds can respond differently to storms.

  • Returning a road to meadow

    Decommissioning typically removes road fill and drainage structures and recontours toward natural grade, so water spreads across the meadow instead of running in a ditch, then revegetates the footprint.

Permits & funding

Regulatory and funding context

Public records describe the environmental review and permits for the Forest Service and RCD project as a whole, not American Engineering's scope.

  • NEPA · Environmental Assessment

    Federal approval

    Lassen National Forest approved the Upper Butte Creek Forest Health Project through an Environmental Assessment, with a decision signed February 18, 2026. The project "aims to improve forest and meadow health and increase resiliency of wildlife habitat, the Wildland Urban Interface and of cultural resources on 19,881 acres."

  • CEQA · SCH No. 2026070148

    State environmental review

    Because parts of the project are expected to use some state funding, the RCD prepared a CEQA Initial Study and draft Negative Declaration. The State Clearinghouse received it July 6, 2026, with public review from July 8 to August 7. Its activities include road route realignment and meadow, riparian and stream restoration.

  • Clean Water Act §404 · §401

    Wetland fill and water quality

    The draft Negative Declaration lists a U.S. Army Corps of Engineers Section 404 permit for fill of possible wetlands or waters of the United States, and Section 401 water quality certification from the Central Valley Regional Water Board, with requirements "determined on a project-by-project basis."

  • CGP · Order WQ 2022-0057-DWQ

    Construction stormwater and grading

    A California construction project that disturbs one acre or more of soil, or is part of a larger common plan of development that will, needs coverage under the State Water Board's 2022 Construction General Permit before any ground is disturbed. The draft document lists SWPPP coverage and a local grading permit as necessary for some road relocation components, including the Humbug–Willow project.

Decommissioning the co-maintained segment needs a written agreement with Butte County or an equivalent document, and the RCD will work with the Konkow Valley Band of Maidu Indians on cultural monitoring during implementation.

  • Land Surveying

    Topographic Surveying

    Topographic surveys of 2.14 miles of Forest Service roads, including 10 stream crossing sites.

  • Stormwater

    Stormwater Calculations

    Culvert sizing calculations.

  • Civil Engineering

    Improvement Plans

    Road relocation and upgrade plans, stream crossings and the engineer's estimate.

  • Civil Engineering

    Grading Plans

    Plans to decommission the road segment through the wetland meadow.

See all past work

Sources

Public records and agency pages behind the project context above. The scope section describes American Engineering's own work.

  1. Humbug Road (Butte County Resource Conservation District)
  2. Willow Creek Meadow (Butte County Resource Conservation District)
  3. Upper Butte Creek Forest Health Project, draft Negative Declaration, SCH No. 2026070148 (received July 6, 2026) (Butte County Resource Conservation District, via CEQAnet)
  4. Upper Butte Creek Forest Health Project (#62761) (USDA Forest Service, Lassen National Forest)
  5. Legacy Roads and Trails (USDA Forest Service)
  6. Construction Stormwater Program: 2022 Construction General Permit, Order WQ 2022-0057-DWQ (State Water Resources Control Board)

Last reviewed .

More past work

Road realignment & stream crossings

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