US 550 at US 160 Supplemental Environmental Impact Statement

JANUARY 2012 UPDATE: The Colorado Department of Transportation (CDOT) and Federal Highway Administration (FHWA) announced the end of the public comment period for the US 550 at US 160 Supplemental Draft Environmental Impact Statement (SDEIS)/Section 4(f) Evaluation on November 29, 2011. The document remains available for viewing online (please click here) and at Durango, Bayfield and Ignacio public libraries, San Juan Public Lands Center, City of Durango, La Plata County and CDOT’s main Durango office. In the Denver area the document is available at CDOT Headquarters and at the FHWA Colorado Division office. A press release on SDEIS details is also available: click here.

The SDEIS became available on October 14 and the 45-day public comment period ended on November 28 (a public open house and hearing was held on November 2 at Escalante Middle School in Durango.) The FHWA is in the process of reviewing all comments, which will be responded to within the final document. A Final EIS Record of Decision will be made in the spring of 2012.

THE INTERCHANGE PROJECT HISTORY
The Environmental Impact Statement (EIS) for the US 160 corridor between Durango and Bayfield was begun in 2001. This EIS included alternatives for a connection with US 550. The EIS Record of Decision (ROD) was completed in November 2006, calling for widening (to four lanes) of US 160 between Durango and Bayfield and identifying the need for three grade-separated interchanges for US 160 through the Grandview area (including one that would connect with US 550).(Click here for information on the US 160 EIS.)

In July 2008 CDOT began a project, identified in the EIS, to construct a second westbound lane into Durango and begin construction on the first interchange. (The final phase of this interchange construction began in March 2011 and will complete a fully-functional interchange by early 2012; please see (Click here for US 160 Durango project information)

In total, the entire interchange project includes the addition of a second westbound lane through Grandview; four interchange bridges and bridge ramps; a 2,020 linear foot shared use path; six highway retaining walls and four path retaining walls; a concrete roundabout on the north side; new access road on the south side; extensive drainage improvements and environmental mitigation. The total cost of the interchange upon completion is estimated at under $47 million.

INTERCHANGE PURPOSE AND NEED – WITH OR WITHOUT US 550
Traffic modeling and area development projections for the original EIS were completed in coordination with the City of Durango and La Plata County, using—among other resources—the city’s “2004 Grandview Area Plan.”

In 2009, on peak travel days an average of 27,875 vehicles traveled this stretch of highway through Grandview. Traffic projections show that by 2030, 44,478 vehicles will travel US 160 on peak travel days near the interchange; factoring in future development laid out in the Grandview Area Plan, this number is 85,910 vehicles per day in 2030 during peak season travel.

In 2008, the FHWA gave approval of the interchange project, acknowledging that the interchange has independent utility with or without a US 550 connection. Because of this, construction on the Grandview Interchange was permitted to continue (without the US 550 connection) while the appropriate environmental work continued to evaluate the future connection alternatives.

Upon completion, the new US 160 interchange will allow safer access to the south-side properties via a frontage road; and in the future, provide safer access to future development to the north. Traffic studies show a traffic signal on this section of highway would fail by 2025—or at full planned development build-out. In fact, three grade-separated interchanges in the Grandview Area east of Durango are called for in the US 160 EIS.

REVIEWING ENVIRONMENTAL PROCESSES FOR THE US 550 CONNECTION TO US 160
CDOT began design of the US 550 connection and discovered there was a gas well that had been constructed in the selected alignment. In 2007, continuing work on the design, CDOT mapped a new alignment that avoided the gas well.

Reviewing environmental clearances as part of this alignment shift, CDOT and the Federal Highway Administration (FHWA), in consultation with the State Historic Preservation Office (SHPO), determined that a portion of the Webb Ranch south of US 160 on the mesa is eligible for the "National Register of Historic Places." (*Background:  as part of the original EIS process, this area had been surveyed for individual historic structures. Since then, the national trend in historic preservation is to consider landscapes—such as ranches and farms as a whole—in addition to individual architectural structures. So while CDOT met all of the existing requirements previously, the approach taken to identify historic sites has changed since the Record of Decision was signed, requiring new analysis.)

A REEVALUATION WAS DONE
To address the designation of the historic properties, the FHWA and CDOT began a process of looking at alignments that avoid or minimize impacts to historic landscapes—four historic ranches and other cultural sites identified in the same area. Five alternatives for a US 550/US 160 connection were examined through a federal Section 4 (f) process that reviews historic and archaeological impacts. By spring 2011, this process resulted in a draft document showing the alignment on the Webb Ranch modified to avoid the gas well is the least impactful to historic and archaeological sites.

The draft 4(f) documents can be found at this link and will be included in the Draft SEIS and made available during the public comment process later in 2011.

NEXT STEP:  A SUPPLEMENTAL ENVIRONMENTAL IMPACT STATEMENT
FHWA determined in April 2011 that a supplemental EIS is required because of the impacts to the historic ranch and archeological sites that were not previously evaluated in the original EIS (see *BACKGROUND above). The supplemental EIS is to the connection of US 550 to US 160. CDOT and FHWA will supplement the existing EIS document and decision to address the newly identified impacts to historic and archaeological sites and any other changes related to the connection of US 550—both natural and manmade, including regulatory. A Supplemental Draft EIS is now available for review and comment through November 28, 2011.

Following the public hearing and public comment period will be the preparation of a Final EIS, and a Record of Decision by FHWA for the connection of US 550 to US 160. This process is expected to be completed by spring 2012.