After collecting feedback from residents and other interested parties regarding flood-related permanent reconstruction of Fourmile Canyon Drive, Boulder County Transportation learned that many would like the designs to eliminate the need for removal of soil and rock from the uphill side of the road. In response, the county and its engineering team created an option wherein earth removal from this side of the road would be unnecessary. This option was presented for comment in late 2015 and is available for review below.
The design team has used public input and updated information to create a third set of designs. This set of designs is available below. These designs were presented an open house on May 25, 2016.
- 30% Designs – Uploaded May 13, 2016 – Presented May 25 – Meeting Displays
- Full Set – This is a large file that may take some time to open. The file has been broken down into smaller components below for easier viewing.
- Introduction
- Removals
- Roadway Plans & Profiles
- Drainage Plans
- Geometric Layout & Retaining Walls
- Cross Sections
- Tree Inventory
- Previous Versions of the Sets of Plans are available below
Our goals for rebuilding the two flood damaged sections of lower Fourmile Canyon Drive in such are to:
- Withstand future flooding.
- Make the road safer.
- Reduce the impact of flooding on residents adjacent to the roadway and creek.
- Maintain the special visual, environmental, and community character of the canyon by minimizing construction impacts.
Design Trade-offs
It’s not possible to rebuild Fourmile Canyon Drive so that it’s safe for travel by all modes and resilient to future weather events without either moving the road away from the creek into the hillside, or strengthening the creek-side of the road.
In all design options, the roadway includes an approximate 1-foot downhill lane shoulder, two 11-foot travel lanes, an approximate 4-foot uphill lane shoulder and a drainage ditch. The primary function of the uphill shoulder is to hold and convey water that is coming down the hillside and prevent it from inundating the road. It also serves as a catch zone for falling rock and debris. In addition, the shoulder provides space for emergency services vehicles and a place for disabled vehicles to get out of the roadway.
Previous Design Options:
South Section of Construction – 1033 to 1653 Fourmile Canyon Drive
- Rock Cut Option – 1033 to 1107 Fourmile Canyon Drive
- Zero Rock Cut Option – 1033 to 1107 Fourmile Canyon Drive
- Rock Cut Option – 1107 to 1177 Fourmile Canyon Drive
- Zero Rock Cut Option – 1107 to 1177 Fourmile Canyon Drive
- Rock Cut Option – 1177 to 1312 Fourmile Canyon Drive
- Zero Rock Cut Option – 1177 to 1312 Fourmile Canyon Drive
- Rock Cut Option – 1312 to 1555 Fourmile Canyon Drive
- Zero Rock Cut Option – 1312 to 1555 Fourmile Canyon Drive
- Rock Cut Option – 1555 to 1685 Fourmile Canyon Drive
- Zero Rock Cut Option – 1555 to 1685 Fourmile Canyon Drive
Comment Form
North Section of Construction -Just South of 4324 to Salina Junction
- Rock Cut Option – 4324 Fourmile Canyon Drive
- Zero Rock Cut Option – 4324 Fourmile Canyon Drive
- Rock Cut Option – 4324 to 4389 Fourmile Canyon Drive
- Zero Rock Cut Option – 4324 to 4389 Fourmile Canyon Drive
- Rock Cut Option – 4389 to 4719 Fourmile Canyon Drive
- Zero Rock Cut Option – 4389 to 4719 Fourmile Canyon Drive
- Rock Cut Option – 4719 to 4726 Fourmile Canyon Drive
- Zero Rock Cut Option – 4719 to 4725 Fourmile Canyon Drive
- Rock Cut Option – 4726 to Salina Junction
- Zero Rock Cut Option – 4726 to Salina Junction