Notice of Adoption of an Interim 602(a) Storage Guideline for Management of the Colorado River

AGENCY:

Bureau of Reclamation, Interior.

ACTION:

Notice of adoption of an interim 602(a) storage guideline for management of the Colorado River.

SUMMARY:

Pursuant to the National Environmental Policy Act (NEPA) of 1969 (as amended), the Bureau of Reclamation has prepared a final environmental assessment (EA) for adoption of an interim 602(a) storage guideline for management of the Colorado River. The Secretary of the Department of the Interior (Secretary), acting through the Bureau of Reclamation, proposed the adoption of an interim 602(a) storage guideline that would assist the Secretary in making a determination of the quantity of water considered necessary as of September 30 of each year, as required by article II(1) of the 1970 Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs pursuant to the Colorado River Basin Project Act of September 30, 1968. See 68 FR 56317 (September 30, 2003).

We are notifying the public that a Finding of No Significant Impact (FONSI) on the proposed guideline was approved by Bureau of Reclamation Regional Directors Rick L. Gold and Robert W. Johnson on March 17 and March 18, 2004, respectively. The text of the FONSI is provided below.

FOR FURTHER INFORMATION CONTACT:

Copies of the final EA and FONSI are available from Tom Ryan, Bureau of Reclamation, Upper Colorado Regional Office, 125 South State Street, Salt Lake City, Utah 84138-1147; telephone (801) 524-3732; faxogram (801) 524-5499; e-mail: tryan@uc.usbr.gov. The final EA and FONSI are also available on Reclamation's Web site at http://www.usbr.gov/uc/library/ (click on Environmental Assessment Documents or Finding of No Significant Impact Documents).

Copies of the EA and FONSI are also available for public review and inspection at the following locations:

• Bureau of Reclamation, Upper Colorado Regional Office, 125 South State Street, Room 7239, Salt Lake City, Utah 84138-1147
• Bureau of Reclamation, Denver Office Library, Denver Federal Center, Building 67, Room 167, Denver, Colorado 80225-0007
• Bureau of Reclamation, Main Interior Building, Room 7060-MIB, 1849 C Street, NW, Washington, DC 20240-0001

Connie L. Rupp,

Assistant Regional Director—UC Region, Bureau of Reclamation.

Finding of No Significant Impact

Adoption of an Interim 602(a) Storage Guideline

I. Introduction

The Secretary of the Interior, acting through the Bureau of Reclamation (Reclamation), has proposed the adoption of an interim 602(a) storage guideline that will assist the Secretary of the Interior in making a determination of the quantity of water considered necessary as of September 30 of each year to assist in implementation of and as required by Article II(1) of the 1970 Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs (Long-Range Operating Criteria) pursuant to the Colorado River Basin Project Act of September 30, 1968. See 68 FR 56317 (September 30, 2003).

Section 602(a) of the Colorado River Basin Project Act (codified at 43 U.S.C. 1552(a)), requires that the Secretary of the Interior make an annual determination of the quantity of water considered necessary to be in storage in Upper Basin reservoirs to provide protection to the Upper Division States of Colorado, New Mexico, Utah, and Wyoming against drought in the Colorado River Basin. This quantity of water is commonly referred to as “602(a) storage.” In years when projected storage in Upper Basin reservoirs is greater than 602(a) storage, and Lake Powell storage is greater than storage at Lake Mead, storage equalization releases are made. Such storage equalization releases are made to maintain, as nearly as practicable, the active storage in Lake Mead equal to the active storage in Lake Powell on September 30 of each year. In years when projected storage in the Upper Basin is less than 602(a) storage, such storage equalization releases from Lake Powell are not made and the operating objective is to maintain a release of a minimum of 8.23 million acre-feet as specified in the Long-Range Operating Criteria.

II. Proposed Action

In July 2000, Reclamation issued a draft environmental impact statement (DEIS) on the proposed adoption of specific criteria, applicable for 15 years, under which surplus water conditions would be determined, and accordingly surplus water made available, for use by the Lower Division States of Arizona, California, and Nevada. During the public comment period for the DEIS, the seven Colorado River Basin States submitted information to the Department of the Interior that contained a proposal for interim surplus criteria and a number of other related issues. This information was published in the Federal Register on August 8, 2000 (65 FR 48531-38). One of the related components of the seven Colorado River Basin States' proposal not directly related to Lower Division surplus determinations is contained in Section V of the Basin States submission, “Determination of 602(a) Storage in Lake Powell During the Interim Period,” and reads as follows:

During the interim period, 602(a) storage requirements determined in accordance with Article II(1) of the Criteria [Long-Range Operating Criteria] shall utilize a value of not less than 14.85 million acre-feet (elevation 3,630 feet) for Lake Powell (65 FR 48537).

Reclamation did not adopt this aspect of the seven Basin States submission based upon Reclamation's finding that this proposal was outside the scope of the proposed action for adoption of interim surplus guidelines. See 66 FR 7775 (January 25, 2001).

This proposed action would adopt this aspect of the Basin States' recommendation and would limit 602(a) storage equalization releases when the storage level in Lake Powell is projected to be below 14.85 million acre-feet (elevation 3,630 feet) on September 30 as an added consideration (guideline) in the annual 602(a) storage determination through the year 2016. Under this guideline, water year releases from Lake Powell would be limited to the minimum objective release of 8.23 million acre-feet when Lake Powell is projected to be below 14.85 million acre-feet (elevation 3,630 feet) on September 30. The proposed guideline would remain in effect through calendar year 2016.

A final environmental assessment (EA), “Adoption of an Interim 602(a) Storage Guideline” (March 2004), has been prepared by Reclamation. In this final EA, the effects of the proposed action (referred to as the Proposed Action Alternative) are analyzed.

III. Summary of Impacts

Reclamation's analysis indicates that there will be limited impacts resulting from adoption of the proposed guideline. Computer simulation modeling of the Colorado River concludes that there is an 88 percent probability that the proposed guideline will not result in any change to the operation of the Colorado River reservoirs. Under some possible future runoff scenarios, there could be some change to storage equalization releases made from Lake Powell under the proposed guideline. Modeling results showed that there is a 12 percent probability that the proposed guideline would modify storage equalization releases from Lake Powell to Lake Mead to some degree. Within this 12 percent probability range, effects were generally minimal. Modeling results indicate that the total volume of water released from Lake Powell through 2016 will be unaffected by adoption of the proposed guideline. The proposed guideline resulted in no long-term effects and there were no effects observed beyond the year 2016.

1. Lake Powell—There is a 12 percent probability that there could be a temporary increase in the water surface elevation of Lake Powell of 0.01 to 6.4 feet, an increase of up to 407,000 acre-feet of storage (an increase of 2.8 percent).

2. Lake Mead—There is a 12 percent probability that there could be a temporary decrease in water surface elevation of 0.01 to 4.1 feet, a decrease of up to 413,000 acre-feet of storage (a decrease of 2.9 percent).

3. River Flows—Changes to river flows below Lake Powell, if they occur, are projected to be minor. Releases from Lake Powell, Lake Mead, and reservoirs below Lake Mead are projected to remain within historical normal operating parameters.

4. Water Supply—There are no anticipated effects on water supply to the Upper Division States of Colorado, New Mexico, Utah, and Wyoming. There is a very small probability (about 1 percent) that the proposed guideline could reduce surplus deliveries to the Lower Division States of Arizona, California, and Nevada in a single year through the year 2016. Computer model studies showed that the proposed guideline would not increase the frequency or magnitude of future water shortages to the Lower Division States.

5. Water Deliveries to Mexico—The proposed guideline is not anticipated to result in any change to the delivery of water to Mexico pursuant to the 1944 United States-Mexico Water Treaty.

6. Water Quality—There could be some minor increases in salinity in Lake Mead.

7. Aquatic Resources—There would be no measurable changes to aquatic resources in the area of potential effects.

8. Special Status Species—There would be no effect to special status species caused by the proposed guideline.

9. Recreation—There are no projected adverse impacts to recreation at Lake Powell, Lake Mohave, or Lake Havasu. There would be no anticipated impacts to Colorado River recreation. The proposed guideline could result in some short-term impacts to recreation resources at Lake Mead related to item 2 above.

10. Hydropower—Changes to hydropower production at Glen Canyon Dam and Hoover Dam are projected to be less than 0.01 percent. There could be some minor incremental increases to pumping costs for the Southern Nevada Water Authority which draws water from Lake Mead.

11. Air Quality—There are no projected impacts to air quality.

12. Visual Resources—There are no projected impacts to visual resources.

13. Cultural Resources—There will be no effect to cultural resources as a result of this undertaking. Reclamation is in the process of compiling data regarding the location of cultural resources (and historic properties) within the area of potential effects of the proposed guideline and the Colorado River Interim Surplus Guideline.

14. Indian Trust Assets—There would be no effect to Indian Trust Assets. The proposed guideline does not allocate additional Colorado River water. There would be no effect on existing or additional tribal water rights and/or tribal allocations.

15. Environmental Justice—There are no environmental justice implications from the proposed guideline.

IV. Finding

Based on the analysis of the environmental impacts as described in the final EA and on thorough review of public comments received, Reclamation has determined that implementing the proposed guideline will not have a significant impact on the quality of the human environment or the natural resources of the area. A Finding of No Significant Impact is justified for the proposed guideline. Therefore, an environmental impact statement is not necessary to further analyze the environmental effects of the proposed guideline.

V. Decision—Interim 602(a) Storage Guideline

Reclamation hereby adopts the following interim 602(a) Storage Guideline:

1. Through the year 2016, 602(a) storage requirements determined in accordance with Article II(1) of the Long-Range Operating Criteria shall utilize a value of not less than 14.85 million acre-feet (elevation 3,630 feet) for Lake Powell. Accordingly, when projected September 30 Lake Powell storage is less than 14.85 million acre-feet (elevation 3,630 feet), the objective will be to maintain a minimum annual release of water from Lake Powell of 8.23 million acre-feet, consistent with Article II(2) of the Long-Range Operating Criteria.

2. Under the current area-capacity relationship at Lake Powell, a water surface elevation of 3,630 feet corresponds to 14.85 million acre-feet of storage. In the event that a sediment survey is performed at Lake Powell and a revised area-capacity relationship is determined before the year 2016, the revised water storage volume that correlates with the water surface elevation of 3,630 feet at Lake Powell shall be used in Section V(1) of this Interim 602(a) Storage Guideline.

3. The Interim 602(a) Storage Guideline shall be utilized in the operation of the Colorado River in years 2005 through 2016. This guideline will first be implemented in the development of the 2005 Colorado River Annual Operating Plan (AOP) and for all subsequent AOPs through the year 2016.