Expanding Local Wells: 5 Wells in the City's Capital Improvement Budget
Flagstaff's water supply partially relies on groundwater pumped from perched aquifers, shallow volcanic aquifers in the Inner Basin, and the deeper C-aquifer. The C-aquifer encompasses 21,655 square miles (ADWR Water Atlas, Eastern Plateau) and includes the Lake Mary and Woody Mountain well fields as well as "in-city" wells. Plans are already underway to install up to five "in-city" wells within the next 10 years.
Extent of the C-aquifer in square miles
Average cost to drill and equip a new well in Flagstaff
Continued Monitoring and Understanding
Our work aims to better understand aquifer and environmental conditions through continued monitoring, data collection, and partnering with the U.S. Geological Survey and the Arizona Department of Water Resources.
The City worked with a consulting firm in 2011 and in 2015 to utilize a U.S. Geological Survey groundwater flow model to define what volume of water Flagstaff could pump and be continually sustained for 100 years without negative consequences to the environment. Spring flows along the Mogollon Rim and Grand Canyon and baseflow to the riparian areas along Clear Creek, Chevelon Creek, and the Little Colorado River, are dependent on flow form the C-aquifer. Other local municipalities also utilize the C-aquifer including Winslow, Holbrook, and the Mogollon Rim region.
Developing Water at Red Gap Ranch
Following a drought and emergency well drilling in 2004, city voters passed a $15 million bond for water rights acquisition and/or water development. The City purchased Red Gap Ranch in 2005. Located 40 miles east of Flagstaff, the ranch was attractive as it came with a proven water supply from the C-aquifer and 8,500 acres of private land.
The City hired JACOBS Engineering to assess the feasibility of constructing a pipeline to this property. The study will define the optimal pipeline alignment and identify requirements for the conceptual design, right-of-way, and environmental regulatory (federal, state, and tribal). It will also estimate costs associated with constructing, operating, and maintaining the pipeline. The feasibility study will outline ways to achieve these goals with the lowest cost, least community impact, least environmental impact, and least risk.
Phase 1 of the three-phase study was complete in 2009. Phase 2 work was halted in 2009 because of issues related to obtaining right-of-way (ROW) access with various entities.
In July 2014, after 5 years of discussions with various agencies and government entities, the City attended a meeting with the Arizona Department of Transportation (ADOT) and the Arizona Department of Water Resources (ADWR). During this meeting, ADOT agreed to work with us to complete the feasibility study and develop an Intergovernmental Agreement (IGA) that identifies the necessary steps for permitting the construction and maintenance of a waterline within the ADOT ROW of Interstate 40. This conversation was memorialized in a letter from the director of ADOT to the Mayor on December 31, 2014 (PDF).
The City has an agreement with the Navajo Nation as to how much water both parties can pump from the aquifer within a certain distance of the boundary. For Flagstaff, that volume is 8,000 acre-feet per year. Flagstaff can legally develop an additional 4,000 acre-feet per year from areas adjacent to the ranch.
Phase 2 of the study should be completed in the Spring of 2018.
- 40 mile pipeline from Red Gap Ranch to Flagstaff
- 2,000 feet of lift from Red Gap Ranch to Flagstaff
- Saltier water than Flagstaff's
- Wells drilled but not equipped
- 4 booster stations