Lower Colorado River Well Inventory

1. Purpose and Objectives: To inventory wells on the flood plain of the lower Colorado River and complete the well inventory on the adjacent alluvial slopes and tributary valleys.

2. Background: Accounting for the consumptive use of Colorado River water withdrawn from the river aquifer by wells requires that each well within the boundary of the river aquifer be located and inventoried in order to apply the method, which can be used to identify those wells that yield water that will be replaced by water from the river.

3. Funding: No funding estimates are available.

4. Description and Approach:

• Wells will be visited in the field and owners interviewed to collect current data required to fill out well inventory forms and to obtain additional ownership information and drillers’ logs.
• Well positions will be determined or updated within 10 meters by using Global Positioning System satellite surveys. Well sites and measuring points will be photographed.
• Water levels will be measured where required and if access is possible.
• Geological Survey and Bureau of Reclamation will inventory forms that will be coded for each well.
• Appropriate data will be entered in the Geological Survey database.

5. Status: Project is still ongoing and no results are available.

6. U.S. Contact: Sandra J. Owen-Joyce, USGS, (520) 670-6671