E6-13751. Notice of Availability; Final Environmental Impact Statement

AGENCY:

Natural Resources Conservation Service, USDA.

ACTION:

Notice of availability.

SUMMARY:

The Natural Resources Conservation Service (NRCS) has prepared a Final Environmental Impact Statement consistent with the National Environmental Policy Act of 1969, as amended, to disclose potential effects to the human environment resulting from proposed flood-control improvements to Coal Creek in Cedar City, Utah.

The section of Coal Creek that traverses Cedar City, Utah, has channel stability and capacity deficiencies that pose a threat to existing infrastructure and development due to flooding. The NRCS proposes to modify the Coal Creek channel to safely convey floodwaters from a 100-year flood event. Also as part of this project, Cedar City proposes to improve and expand an existing parkway along Coal Creek to enhance aesthetic values and provide recreational opportunities for community residents and visitors.

The Final EIS presents detailed analyses for three alternatives. Alternative A—No Action, would continue the frequency and level of dredging and other management actions as they are currently planned. Existing channel and structural deficiencies would not be corrected. Recreational opportunities associated with the creek would remain as they currently exist.

Because of the purpose and need of the project, several proposed elements are common to both of the action alternatives (Alternatives B and C). Both action alternatives include modifying channel cross sections, altering the stream gradient in particular sub-reaches, stabilizing actively eroding banks, and constructing levees. Bank stabilization would be accomplished by laying the river banks back to a stable slope that supports channel stabilization methods and then armoring the banks via the use of rock (riprap), vegetation, soil cement, erosion control fabric, or some combination of these items. Existing riparian habitat and vegetation would be preserved on the streambanks, where possible. It is anticipated that both sides of the channel would be armored with riprap through the suburban corridor from Center Street to I-15 to prevent bank erosion from high stream velocities during flood events. Elements unique to each action alternative are listed below.

Alternative B—Relocate Main Street Diversion, would remove the Main Street diversion/drop structure currently in use and relocate it to near 200 East. Implementation of this alternative would require approximately 3,550 feet of pipeline to be installed, flood and slope/grading-related channel modifications from Center Street to I-15, and the continuation of periodic dredging as necessary. A sedimentation basin would be constructed to remove gravels from diverted irrigation water. The Woodbury diversion/drop structure would be reconstructed. Under this alternative, the parkway would be extended west to Airport Road and landscaped. Parkway Option B1 proposes a crosswalk at the Main Street Bridge. Parkway Option B2 proposes to access existing sidewalks from the pedestrian bridge at 400 North to cross Main Street and avoid additional property acquisition.

Alternative C—Replace Main Street Diversion, would replace the Main Street diversion/drop structure by constructing a new structure that would have approximately half the drop. Implementation of this alternative would require the installation of approximately 4,900 feet of pipeline, flood and slope/grading-related channel modifications from Center Street to west of I-15, and the continuation of periodic dredging as necessary. Two sedimentation basins would be constructed to remove gravels from diverted irrigation water. Additionally, the Woodbury diversion/drop structure would be reconstructed to allow for the safe passage of floodwaters. Under this alternative, the parkway would be extended to Airport Road and landscaped. In addition, a historic pedestrian truss bridge would be removed to prevent channel constriction and potential flooding. Parkway Option C1 would construct an elevated pedestrian pathway under the Main Street Bridge. Parkway Option C2 would construct a large box culvert for pedestrian use just north of the bridge and under Main Street.

In response to public comment on the Draft EIS and to alleviate localized flooding tied to Coal Creek discharge levels, an additional option (the North Field Canal Option) was analyzed in the Final EIS. Under Alternative C, this option would construct a subgrade pipeline for several hundred feet along the southern portion of the North West Field Canal. It would traverse undeveloped city-owned property west of the Cedar City Cemetery, and follow the North Field Canal corridor from a point just south of 900 North Street to 1045 North Street. Water would be piped east and west along 1045 North Street to both the Union Field and Northwest Field Canals.

As required by the NRCS for water projects, the National Economic Development (NED) benefit-cost process was used to determine benefit-cost ratios for each alternative. All of the action Alternative/Option combinations have a benefit-cost ratio of 1.9:1 and are all considered viable NED Alternatives. The sole exception to this is Alternative C when coupled with Parkway Option C2 and the North Field Canal Option, which has a benefit-cost ratio of 1.8:1. This indicates that the costs and benefits of all of the alternatives are relatively consistent.

Under CEQ regulations and the NRCS National Environmental Compliance Handbook, Section 610.38—Distribution and Publication of Environmental Documents, a Record of Decision (ROD) cannot be prepared until the Final EIS has been available to the public for at least 30 days. Comments will be accepted on the FEIS during this period. Following this review period, notice of the ROD's availability will be published in the Federal Register.

Effective Date: September 1, 2006.

FOR FURTHER INFORMATION CONTACT:

Marnie Wilson, Coal Creek EIS, USDA—NRCS, Wallace F. Bennett Federal Building, 125 South State Street, Room 4402, Salt Lake City, UT 84138-1100. Project information is also available on the Internet at: http://www.ut.nrcs.usda.gov under Public Notices.

SUPPLEMENTARY INFORMATION:

Copies of the Final EIS are available by request from Marnie Wilson at the address listed above. Basic data developed during the environmental evaluation are on file and may be reviewed by contacting Sylvia Gillen, Utah State Conservationist.

Signed in Salt Lake City, Utah, on August 11, 2006.

Sylvia A. Gillen,

State Conservationist.