Colorado, I-70: Maximum Preservation and Innovation
Initial plans for I-70 through Glenwood Canyon in Colorado included blasting through the cliff, using ugly retaining walls, and channeling the Colorado River. But those plans were soon to change.
The Colorado Highway Commission's lone environmental member helped to form a Citizens Advisory Committee (CAC) of design and ecological professionals, with members from the Colorado Open Space Coalition and western Colorado interests. The group was active throughout the NEPA review process until the highway's completion in 1992.
The result is a 12.5-mile stretch of highway with lower environmental impacts — thanks in large part to NEPA's procedural protections. In 1978, after two years of design review, CDH (Colorado Department of Highways) brought the p roposal before the public. Their proposal incorporated elements of natural and social sciences and environmental design in the highway's planning
and decision-making. These citizens' concerns were incorporated into the final design, including the CAC suggestion to place a section of the highway in tunnels to protect the scenic Hanging Lake area from noise and visual impacts.
The final design preserves the natural topography and maintains the integrity of the Colorado River and side rivers entering it. Eastbound and westbound lanes often diverge with one lane rising over a bridge or ducking through a tunnel, preserving
the canyon floor, walls, vegetation, and river where ver possible. Forty bridges and viaducts (totaling 6.5 miles) and three tunnels minimize the highway's impact on its surrounding environment. Also, the speed limit was set at 50 miles per hour (as opposed to the original 60 mph) to improve safety.
Additionally, a construction technique called balanced cantilever construction allowed each section of the highway to be built on bridge columns, reducing damage to the canyon. Workers were fined for damaging vegetation marked for preservation. Features such as four rest stops, a bike and jogging path along the length of the canyon, a boat launch, and a raft drop allowed for canyon recreational use by tourists and regional residents.
Placing the highway section near Hanging Lake into tunnels ensures that hikers in this area continue to enjoy their experience.
"NEPA helped engineers to understand ecology and environmental design. In this case, without it, the CAC would have been ignored or abolished and the unique Canyon would have been destroyed. NEPA ensured that citizens and design professionals were heard in preserving the Canyon," said Bert Melcher, citizen activist.
Indeed, the Glenwood Canyon project has received more than thirty awards for innovative design and environmental sensitivity. The American Society of Civil Engineers awarded the project the Outstanding Civil Engineering Achievement Award in 1993. Melcher concludes, "This proves that NEPA works."
Photo courtesy Federal Highway Administration/Elizabeth E. Fischer; used with permission.
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