Fourmile Canyon Reconstruction

Fourmile Canyon Reconstruction

This webpage is your source for information regarding permanent flood recovery-related reconstruction in lower Fourmile Canyon between Boulder Canyon Drive/CO 119 and Salina Junction.

Background:

In September 2013, flood waters either damaged or destroyed approximately 1.5 miles of two sections of Fourmile Canyon Drive between Boulder Canyon Drive and Salina Junction. The lower portion (south section) starts about 1-mile up from Boulder Canyon Drive and extends to Poorman Road, and the upper portion (north section) starts near Logan Mill Road and extends up to Salina Junction. The projects to repair Logan Mill Road/Bridge, Upper Fourmile Canyon & Gold Run Road are separate from this project.

Permanent design plans are currently being refined. The county’s most recent estimate is that construction will start in the Winter/Spring of 2018.

CURRENT DESIGNS

90% Complete Plan Set for Roadway Work – Uploaded March 9, 2017

This plan set has been broken into smaller pieces to make the files easier to open. The files below include both the north and south sections of lower Fourmile Canyon Drive (Hwy 119 to Salina Junction). These plans will continue to be revised as we work with impacted property owners.

  • Pages 1 to 34 – Title Sheet, Symbols, Notes, Typicals, Quantities, Tabulations, Survey Control, Key Map, and Geometric Layout
  • Pages 35 to 50 – Removals & Resets
  • Pages 51 to 79 – Tree Inventory*
    • *NOTE – The tree inventory is still being updated and do not depict the actual tree figures. We’re also working on contract language that will require the contractor to save as many trees as possible. While it is unlikely we will be able to prevent all tree removals, we will ensure that only those tree that are absolutely necessary will be removed.There will also be a large revegetation effort at the end of the project.
  • Pages 80 to 109 – Roadway Plans & Profiles
  • Pages 110 to 125 – Driveways
  • Pages 126 to 159 – Creek and drainage plans
  • Pages 160 to 221 – Culverts & Retaining Walls
  • Pages 222 to 250 – Guardrail, Construction Phasing*, and Storm Water Master Plans
    • *NOTE – The Construction Phasing Plans are only suggestions made by our engineering consultant. The county is working internally on a plan to complete this project with minimal impacts to residents and the traveling public.
  • Pages 251 to 291 – Cross Sections

This plan set has been broken into smaller pieces to make the files easier to open. The files below include both the north and south sections of lower Fourmile Canyon Drive (Hwy 119 to Salina Jct.)

Lower Fourmile Creek Stream Restoration Plans – Uploaded Feb. 23, 2017

These are the designs that will be used to guide the stream restoration component of the project. The plan set has been broken into smaller sections for easier downloads.

60% Complete Phase for Roadway

This plan set has been broken into smaller pieces to make the files easier to open. The files below include both the north and south sections of lower Fourmile Canyon Drive (Hwy 119 to Salina Junction). These plans will continue to be revised as we work with impacted property owners.

Lower Fourmile Canyon Drive Reconstruction Options that helped inform the 60% phase.

News – Upcoming Events:

TREE UPDATE – Feb. 10, 2017

On Jan. 26, members of the Fourmile Canyon Drive engineering team, including Transportation Director George Gerstle and County Engineer Mike Thomas, walked both stretches of lower Fourmile Canyon Drive where the road will be permanently reconstructed to better understand and mitigate impacts to trees, bushes, and other vegetation identified for potential removal.

Each tree identified in the recent draft design was carefully inspected, and possible measures to avoid removal were discussed. The design team has now been charged with saving as many trees as possible through creative design changes, transplanting of trees, or by incorporating special construction techniques to avoid impacts. In addition, we are incorporating language in the construction contracts to incentivize contractors to mitigate impacts to trees during construction. The same tree evaluation will be held with the design team in Gold Run and in upper Fourmile/Wall Street in the coming weeks and the goal will be the same; to save as many trees as possible.

While we will make every effort to mitigate impacts to trees during construction it will not be possible to avoid all tree removals. Based on early public input, the conceptual design of the road repairs were changed to avoid impacts to the canyon walls on the uphill side of the road. The recognized trade-off to these changes was that some increased impacts to creek-side vegetation were unavoidable as retaining walls would be necessary to strengthen and protect the road from future flood events. Where trees must be removed from private property, we are discussing options with the property owner. When a significant tree must be removed from the right-of-way, we will plant a new tree in the canyon, understanding that a new tree is unlikely to be the same as an old-growth tree.

It is our promise to residents that we will make every effort to remove only those trees that absolutely must go to complete the project. We have heard concerns from both residents and visitors to the canyon about the loss of trees from the Fourmile Fire and subsequent flood events, and how that has changed the canyon’s aesthetics. We will do everything we can to minimize more changes to the character of this beautiful canyon as a result of permanent flood repairs.

Previous Meetings:

Project Contacts:

Contact Us

Transportation Department

303-441-3900
Submit a question

Location

2525 13th Street
Boulder, CO 80304

Map & Directions

Hours: 8 a.m. - 4:30 p.m. M-F

Mailing Address

P.O. Box 471
Boulder, CO 80306