E9-26164. Availability of the Draft Environmental Impact Statement for the Moffat Collection System Project, City and County of Denver, Adams County, Boulder County, Jefferson County, and Grand County, CO

AGENCY:

Department of the Army, U.S. Army Corps of Engineers, DoD.

ACTION:

Notice of availability.

SUMMARY:

The U.S. Army Corps of Engineers (Corps) Omaha District has prepared a Draft Environmental Impact Statement (EIS) to analyze the direct, indirect, and cumulative effects of a water supply project called the Moffat Collection System Project (Moffat Project) in the City and County of Denver, Adams County, Boulder County, Jefferson County, and Grand County, CO. The purpose of the Proposed Action is to develop 18,000 acre-feet (AF) per year of new, firm yield to the Moffat Water Treatment Plant (WTP) and raw water customers upstream of the Moffat WTP pursuant to the Board of Water Commissioners' commitment to its customers. Denver Water's need for the proposed Moffat Project is to address two major issues: (1) Timeliness: the overall near-term water supply shortage, and (2) location: the imbalance in water storage and supply between the North and South systems. The Moffat Project would result in direct impacts to jurisdictional waters of the United States (U.S.), including wetlands. The placement of fill material in these waters of the U.S. for the construction of water storage and distribution facilities associated with developing additional water supplies requires authorization from the Corps under Section 404 of the Clean Water Act. The Permittee and Applicant is the City and County of Denver, acting by and through its Board of Water Commissioners (Denver Water).

The Draft EIS was prepared in accordance with the National Environmental Policy Act (NEPA) of 1969, as amended, and the Corps' regulations for NEPA implementation (33 Code of Federal Regulations [CFR] parts 230 and 325, Appendices B and C). The Corps Omaha District, Denver Regulatory Office is the lead federal agency responsible for the Draft EIS and information contained in the EIS serves as the basis for a decision regarding issuance of a Section 404 Permit. It also provides information for local and state agencies having jurisdictional responsibility for affected resources.

DATES:

Written comments on the Draft EIS will be accepted on or before January 28, 2010. Public open houses and hearings will be held on December 1, 2, and 3, 2009.

ADDRESSES:

Send written comments regarding the Proposed Action and Draft EIS to Scott Franklin, Moffat EIS Project Manager, U.S. Army Corps of Engineers, Omaha District—Denver Regulatory Office, 9307 South Wadsworth Boulevard, Littleton, CO 80128 or via e-mail: [e-mail]. Requests to be placed on or removed from the mailing list should also be sent to this address.

FOR FURTHER INFORMATION CONTACT:

Scott Franklin, Moffat EIS Project Manager, U.S. Army Corps of Engineers at 303-979-4120; Fax [phone].

SUPPLEMENTARY INFORMATION:

The purpose of the Draft EIS is to provide decision-makers and the public with information pertaining to the Proposed Action and alternatives, and to disclose environmental impacts and identify mitigation measures to reduce impacts. Denver Water proposes to enlarge its existing 41,811 AF Gross Reservoir by 72,000 AF to a total storage capacity of 113,811 AF. Gross Dam is located in Boulder County, CO, approximately 35 miles northwest of Denver and 6 miles southwest of the city of Boulder. The enlargement would be accomplished by raising the existing concrete gravity arch dam by 125 feet, from 340 to 465 feet high. The surface area of the reservoir would be expanded from approximately 418 acres to 818 acres. Using existing collection infrastructure, water from the Fraser River, Williams Fork River, and South Boulder Creek would be diverted and delivered during average to wet years via the Moffat Tunnel and South Boulder Creek to Gross Reservoir. There would be no additional diversions in dry years because Denver Water already diverts the maximum amount physically and legally available under their existing water rights. In order to firm this water supply and provide 18,000 AF per year of new firm yield, an additional 72,000 AF of storage capacity is necessary. To meet future demands, in most years, Denver Water would continue to rely on supplies from its entire integrated collection system. In a drought or emergency, Denver Water would rely on the additional water it would have previously stored in the Moffat Collection System to provide the additional 18,000 AF of yield.

In addition to the Proposed Action (Alternative 1a)—Gross Reservoir Expansion (Additional 72,000 AF), the Draft EIS analyzes five alternatives: (1) Alternative 1c—Gross Reservoir Expansion (Additional 40,700 AF)/New Leyden Gulch Reservoir (31,300 AF), (2) Alternative 8a—Gross Reservoir Expansion (Additional 52,000 AF)/Reusable Return Flows/Gravel Pit Storage (5,000 AF), (3) Alternative 10a—Gross Reservoir Expansion (Additional 52,000 AF)/Reusable Return Flows/Denver Basin Aquifer Storage (20,000 AF), (4) Alternative 13a—Gross Reservoir Expansion (Additional 60,000 AF)/Transfer of Agricultural Water Rights/Gravel Pit Storage (3,625 AF), and (5) No Action Alternative, which assumes that Denver Water would not receive approval from the Corps to implement the Moffat Project. Denver Water would rely upon a combination of strategies including using a portion of its Strategic Water Reserve and imposing mandatory restrictions to reduce demand during droughts.

Copies of the Draft EIS will be available for review at:

1. Arvada Library, 7525 W. 57th Avenue, Arvada, CO 80002.

2. Boulder County Main Library, 1001 Arapahoe Avenue, Boulder, CO 80302.

3. Denver Central Library, 10 W. 14th Avenue Parkway, Denver, CO 80204.

4. Fraser Valley Library, 421 Norgren Road, Fraser, CO 80442.

5. Golden Library, 1019 10th Street, Golden, CO 80401.

6. Granby Library, 55 Zero Street, Granby, CO 80446.

7. Kremmling Library, 300 S. 8th Street, Kremmling, CO 80459.

8. Summit County Library North Branch, 651 Center Circle, Silverthorne, CO 80498.

9. Summit County Library South Branch, 504 Airport Road, Breckenridge, CO 80424.

10. Thornton Branch Library, 8992 Washington Street, Thornton, CO 80229.

11. Denver Water, 1600 W. 12th Avenue, Denver, CO 80204.

12. U.S. Army Corps of Engineers, Denver Regulatory Office, 9307 S. Wadsworth Boulevard, Littleton, CO 80128.

13. Electronically at https://www.nwo.usace.army.mil/​html/​od-tl/​eis-info.htm.

Oral and/or written comments may also be presented at Open Houses and Public Hearings to be held at 4 p.m. (Open House) and 6 p.m. (Public Hearing) on Tuesday, December 1, 2009 at the Boulder Country Club (7350 Clubhouse Road), Boulder, CO; at 4 p.m. (Open House) and 6 p.m. (Public Hearing) on Wednesday, December 2, 2009 at The Inn at SilverCreek—Grand Ballroom (62927 US Highway 40) Granby, CO; and at 4 p.m. (Open House) and 6 p.m. (Public Hearing) on Thursday, December 3, 2009 at the Doubletree Hotel—Grand Ballroom II (3203 Quebec Street), Denver, CO.

Timothy T. Carey,

Chief, Denver Regulatory Office.