The rule will help ensure the long-term sustainability of the lower Colorado River, which over the past eight years has been affected by the worst drought conditions that have been experienced in the Colorado River Basin in approximately 100 years of recorded history. It will also protect the water rights of lower Colorado River water entitlement holders.

"Reclamation is legally obligated to ensure that all Colorado River water use in the Lower Basin is covered by an entitlement and correctly accounted for," said Lorri Gray, the Lower Colorado Region's Regional Director. "If someone is using Colorado River water without an entitlement, that harms the entitlement holders in Arizona, California and Nevada who do have one, so this proposed rule is necessary and appropriate."

The 1928 Boulder Canyon Project Act requires all Colorado River water users in the lower basin to have an entitlement to Colorado River water. Current data indicate that 9,000 to 15,000 acre-feet of Colorado River water is used in the lower basin each year by entities and individuals who do not have an entitlement to that water. Most of this use is from wells located in the river's floodplain and hydraulically connected to the river. The proposed rule will:

* establish the methodology Reclamation will use to determine if a well pumps water that is replaced with water drawn from the lower Colorado River;

* establish the criteria a water user must satisfy to demonstrate that his/her well does not pump water that is replaced with water drawn from the lower Colorado River; and,

* establish a process for a water user to appeal a determination that a specific well pumps water that would be replaced by water withdrawn from the lower Colorado River.

"We want to emphasize that a key goal of this rule is to help those well owners who are using Colorado River water without a legal entitlement become lawful users of that water, through the development of contracts or by becoming customers of existing entitlement holders," Gray said.

Reclamation is seeking comments on the proposed rule, including those that identify any specific or potential economic impacts and the estimated costs of those impacts to members of the public or to small businesses located within the boundary of the river aquifer.

A copy of the proposed rule and maps showing the aquifer boundary can be viewed on Reclamation's web site at http://www.usbr.gov/lc/region/programs/unlawfuluse.html (Please note: Figure 7, "Yuma Accounting Area," which is located at the end of the Federal Register Notice of the proposed rule, contains an error regarding the depiction of the groundwater divide and an error in the accounting surface near Yuma, Arizona. A correct Figure 7 is available for viewing on Reclamation's Lower Colorado Region web page under "Unlawful Use Regulation - Index Economic Analysis Attachment 1 - Maps of the Colorado River Aquifer.")

Comments must be submitted by September 15. They may be submitted by e-mail to the Federal rulemaking website at http://www.regulations.gov or by mail. The rule is identified by the number 1006-AA50.

If submitting comments by e-mail, follow the instructions on the web site for submitting comments, using Docket ID: BOR-2008-0001. To submit them by mail, send them to: Bureau of Reclamation, Attention: BCOO-1000, P. O. Box 61470, Boulder City, NV 89006-1470. Please include the number 1006-AA50 and the Docket ID (BOR-2008-0001) in your correspondence. For additional information about the proposed rule, contact Margot Selig at (702) 293-8192.

Reclamation is also planning to conduct meetings to obtain public comment on this proposed rule. The dates, times and locations of the meetings will be published once they have been scheduled.