History of Flagstaff's Water System

The City of Flagstaff was established in 1882 as a railroad stop for train water. Passengers first used spring water near what is now known as “Old Town Spring” adjacent to Mars Hill. This water source was very limited and a new supply was soon needed. After the City became incorporated in 1884 with only 1,500 residents, Mayor Abineau began the first of three major water-supply importation projects from outside City limits.

The Inner Basin Pipeline

The City’s first reliable water supply came from within the San Francisco Peaks, where a 12-mile, 6-inch clay pipeline was constructed from the Inner Basin through Schultz Canyon to a 2.5 million-gallon reservoir located north of Flagstaff along what is now Schultz Pass Road. An 8-inch cast iron pipeline continued into town. Additional improvements of Jack Smith, Flagstaff, and Snowslide Springs, located between 9,600 and 11,020 feet, were conducted by the City and Arizona Lumber & Timber Company in 1899 and 1900, respectively. The new water system had about 300 customers who paid $2 per month — at the time, a day’s wage for most men (Cline, 1994) — about $52.41 in 2010 dollars (USBLS, 2010).

The Lake Mary Dam

Seeking additional surface water supplies in early 1905, T.A. Riordan constructed lower Lake Mary Dam over 6 miles away, southeast of the City limits, in what was then known as Clark Valley. This dam, which captured surface water within the Walnut Creek watershed, represents the City’s second major water supply importation project. Lake Mary and the dam were named after Riordan’s oldest daughter, Mary.

A Sewer System, at Last

As the City’s water demands grew, the City purchased the small, private sewer company that contained over 4,500 feet of 12-inch main in 1917 (Cline, 1994). This was important since sewage disposal became a problem after the new water system allowed many buildings to be constructed with toilets. The sewer discharged into “sewer canyon” southeast of town, near today’s Butler Avenue and the Rio de Flag. According to Cline (1994), the cost of the sewer company was $60,000 — $1.205M in 2010 dollars (USBLS, 2010). Since most citizens in rural America at the time had never had to pay for sewer services, the connection fee of $60 was a sticking point ($1,025 in 2010 dollars (USBLS, 2010)). Additionally, each customer was then charged an annual fee of $9, or $0.75/month ($12.81/month in 2010 dollars (USBLS, 2010)).

A New Inner Basin Reservoir

The Santa Fe Railway constructed a new 50 million-gallon reservoir to expand Inner Basin water storage capacity in 1914 at the Schultz Pass Road facility. The City then voted in 1925 to construct a second 52 million-gallon storage reservoir, upsize the pipeline from the Inner Basin to 14 inches, and purchase the water rights and infrastructure from the railroad for $475,000 ($5.9M in 2010 dollars (USBLS, 2010).

A Second Lake Mary Dam

Given the intermittent nature of the flows in Walnut Creek and the high infiltration rates in the bottom of lower Lake Mary, a second dam was constructed upgradient. Upper Lake Mary Dam and the Lake Mary Water Treatment Plant (WTP) were constructed in 1941 for $200,000 ($2.97M in 2010 dollars (USBLS, 2010)) to store, treat, and deliver this surface water directly to the citizens of Flagstaff. The dam was then raised 10 feet in 1951 to its current height and has a storage capacity of 16,300 acre-feet (AF; Hornerwer and Flynn, 2008).

Extending the Sewer Line

In 1950, Arizona health standards required the City to spend $192,000 ($1.74M in 2010 dollars (USBLS, 2010)) to replace old sewer lines and extend new ones. However, in lieu of building a wastewater treatment plant at the time, the City simply extended the sewer outfall 1/2 mile farther downstream in the Rio de Flag. One benefit of this effort was to essentially eliminate all of the outdoor privies that remained in the City.

Our First Well

Also during the 1950s, drought required the City to look for a more reliable water supply beyond surface water. The City conferred with U.S. Geological Survey geologist John Harshbarger about drilling a well in the Woody Mountain area located over 5 miles southwest of town (Cline, 1994). Not only did this well become the City’s first use of groundwater but it also represents the City’s third major water-supply importation project. The first well was drilled and completed in 1954.

Our First Wastewater Treatment Plant

Constructed in 1956, the City’s first wastewater treatment plant (WWTP) began operating in the Rio de Flag, upstream of today’s Foxglenn Park (Cline, 1994). The plant capacity was 1 million gallons per day (MGD) and cost $530,000, or $4.26M in 2010 dollars (USBLS, 2010).

Formation of a Water Commission

In 1958, water matters had become so urgent that the City Council established a citizens advisory group — the precursor to today’s Water Commission. Six members were appointed to the Water Use and Utilization Commission, which included the Mayor and City Manager (Cline, 1994).

A New Wellfield & Water Treatment Plant

The City continued expanding its groundwater supplies by developing a wellfield adjacent to Lower Lake Mary starting in 1963. Additionally, a new 8 MGD Lake Mary WTP was constructed adjacent to the original 1941 facility to take advantage of surface water stored in Upper Lake Mary.

Our Second Wastewater Treatment Plant

In 1971, in response to federal and state agency warnings about the quality of the wastewater being discharged into the Rio de Flag, the Wildcat Hill WWTP was constructed at a cost of $3.1M or $16.75M in 2010 dollars (USBLS, 2010). The 3 MGD plant located in east Flagstaff became operational in November of that year (Cline, 1994). The plant capacity was subsequently increased to 6 MGD in 1981.

Our Original Adequate Water Supply Designation

As part of the State’s Water Adequacy Program, the City of Flagstaff, along with several other municipal providers, was designated as having an Adequate Water Supply on May 17, 1973. However, at the time, the City was never required to prove hydrologically that it had adequate water supplies to support existing and projected water needs 100 years into the future (ADWR, 2008).

First Use of Reclaimed Water

The City’s first direct use of reclaimed water was at the Continental Country Club golf courses in 1975; this water came from Wastewater Plant #1, which supplied about 1 MGD (Turner, 2010). The City expanded its reclaimed water system with the construction of the 4 MGD Rio de Flag Water Reclamation Facility (WRF) and the 2 million-gallon storage tank at Buffalo Park in 1993. The tank was converted from potable to reclaimed water to provide for reliable storage and delivery.

Groundwater Development & Local Wells

While surface water supplies were first developed outside of the City limits in the late 1880s, groundwater supplies were not developed within the City limits until nearly 110 years later. In 1997, the City began drilling wells locally; we now have seven operating wells and one — the Stonehouse Well — that will be connected to the distribution system in 2016 or 2017.

First Water Conservation Ordinance

To address the continued increase in water use within Flagstaff, the City Council adopted the first water conservation ordinance in November 1990. This ordinance established the City’s water conservation program and required water-saving devices, such as low flow toilets.

Drought Hits the City Hard in 2002

For the only time since adoption of the drought management plan by City Council, the City implemented the plan up to level 3 of 4 "water available strategies." Customers were not accustomed to watering rules and the response to the odd-even watering days and watering times was too slow to make a difference. The City progressively instituted up to level III strategy in order to keep peak water demand below the capacity available from groundwater wells. 

During this time, the City was drilling two water wells and citizens passed a bond election in 2003 to pursue future water supplies. City Council also adopted a modified code that brought the water availability strategies from 4 to 3 such that the first level included the odd-even watering days and watering times. This "Water Awareness Strategy Level I" made water rules mandatory such as to instill a year-round water awareness in the community.

Water Conservation Program Established in 2003

Part of the trouble in 2002 was the lack of enforcement staff addressing watering violations. A Water Conservation Program was established in 2003 with a full-time staff person and two water conservation enforcement staff. Additional money was added to fund a more robust water conservation program.

Purchase of Red Gap Ranch for a Secure Future Water Supply

In 2005, residents voted for a $15 million dollar bond to secure future water supplies. The City purchased Red Gap Ranch, 40 miles east of Flagstaff, as a future water supply, for $11M. The Ranch was demonstrated as having high groundwater yields that could meet buildout water demand for Flagstaff, with a minimum impact to the aquifer.

Expansion of Our Reclaimed Water System

In 2009, the City expanded its reclaimed water system in two ways. First, it upgraded the treatment technology at the Wildcat Hill WWTP to produce Class A+ water. It also constructed an additional booster facility and pipeline to facilitate reclaimed water delivery. These additions now connect the plant to the citywide reclaimed water distribution system and the storage tank at Buffalo Park, improving reliability and allowing for the increased use of reclaim water within the City.

Schultz Fire and Reconstruction of the Inner Basin Pipeline

The Schultz Fire began in June 2010 and was followed by an extreme monsoon storm which heavily damaged the landscape and water infrastructure in the burn area. Over the next two years, the Inner Basin pipeline was reconstructed and relocated as part of a joint effort between City, County, USFS, state and federal agencies. Learn more about the project here, and follow along with recent updates as we reflect on lessons learned in the context of new fires.

City’s First Groundwater Flow Modeling Work (2012) — Sustainable Water Supply

A groundwater flow model is an essential tool for water resource planning. The sophisticated computer model is used to simulate groundwater conditions. The model is calibrated to previous groundwater levels in order to predict future conditions with a level of confidence acceptable in the practice. The results suggest that 9,900 acre-feet of water can be pumped from the aquifer in the areas of our current well fields per year for at least 100 years as sustainable yield.

Renewed Designation of Adequate Water Supply

In 2012, at the direction of the City Council, Flagstaff applied for a renewed Designation of Adequate Water Supply. To demonstrate the physical availability of supplies — one of the criteria for the designation — we conducted a hydrological analysis using a U.S. Geological Survey groundwater flow model. In addition, we demonstrated the City’s fiscal and legal ability to supply water that meets or exceeds Safe Drinking Water Act standards for the projected growth demands over the next 100 years. Flagstaff was granted the renewed Designation on April 1, 2013.

Environmental Studies at Red Gap Ranch

In 2013, the City began working with Southwest Groundwater on a modeling study that addressed the possible impacts to baseflow in perennial reaches of the Little Colorado River, Clear Creek, and Chevelon Creek in response to pumping at Red Gap Ranch. This joint effort conducted with the Navajo Nation also looked at pumping from their proposed Leupp Wellfield, several miles north of Red Gap Ranch. The study was completed in 2015 and also included a biological and cultural assessment of the City’s 7,500 acres. It was funded by a $300,000 Rural Water Supply grant from the U.S. Bureau of Reclamation.

ADEQ Consent Order (2012 to 2014)

Utilities experienced process issues at the Wildcat Hill Water Reclamation Plant that were related to denitrifying the effluent effectively to Class A+ standards. End users of reclaimed water only require Class A water. However, Utilities elected to temporarily fix the issue until the plant is upgraded.

Planned Wellfield Expansion

In 2016, the City began working with Clear Creek Associates on a study to locate new well sites. The water rates adopted by the City Council in 2016 cover the costs of drilling five wells over a 10-year period. This gives Utilities the ability to stay in front of new water demands as the city grows in population.

Utilities Changed Name to Water Services Division A blue water droplet with an outline of the San Francisco Peaks and text

In 2017, the Utilities Division changed its name to the Water Services Division, which better conveys what services we provide to our community. Everything we do revolves around water, whether that's producing drinking water, treating wastewater, providing reclaimed water, or managing stormwater. This change was part of an effort to increase our visibility and keep the public better informed about important issues and projects that pertain to water.