The Winter Season Provides the Public with Ism. However, the Absence Or
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Possible Impacts of Snowmaking Using Reclaimed Water on Water Resources and Other Related Issues in Flagstaff, Arizona Item Type text; Proceedings Authors Leao, Duncan; Tecle, Aregai Publisher Arizona-Nevada Academy of Science Journal Hydrology and Water Resources in Arizona and the Southwest Rights Copyright ©, where appropriate, is held by the author. Download date 24/09/2021 19:51:58 Link to Item http://hdl.handle.net/10150/296600 POSSIBLE IMPACTS OF SNOWMAKING USING RECLAIMED WATER ON WATER RESOURCES AND OTHER RELATED ISSUES IN FLAGSTAFF, ARIZONA Duncan Leao and Aregai Teclei The winter season provides the public with Although snowmaking can provide many bene- numerous outdoor recreational opportunities. Ski-fits to the economy of Flagstaff, several factors ing is a major activity that many people participate must be considered before implementing a snow- in and benefit from during the winter months. In making program. The objective of this paper is to addition to its recreational value, local businesses describe the requirements for snowmaking and its such as restaurants, hotels, and equipment rental potential impacts on regional water resources and shops all profit from winter recreation and tour- many other components of the ecosystem in the ski ism. However, the absence or interruption of area and downstream from it. In addition, some tourism due to insufficient snowfall seriously recommendations are made concerning the imple- affects many businesses. The recurring drought in mentation of snowmaking in the area. the Southwest, which produces insufficient snow- fall during winter, has become a problem that is SITE DESCRIPTION affecting many ski areas in the western United Arizona Snowbowl is located 14 miles north of States. Flagstaff, Arizona, on the San Francisco Peaks One solution that is employed by 91 percent of within the Coconino National Forest (Figure 1). At the ski areas in the West is artificial generation of a present, the total skiing area consists of 205 acres. sustainable snow supply (J. R. Murray, Arizona The elevation of the skiing area at Snowbowl Snowbowl manager, personal communication ranges from 9200 feet at the base to 11,500 feet at 2003). Recent abnormal weather patterns and un- the top (Murray, personal communication 2003). seasonably warm and dry winters in northern Ari- The hydrology of the area is primarily influenced zona have led the Arizona Snowbowl, a ski facility by two seasonal precipitation types: winter snow operating since 1938 near Flagstaff, Arizona, to and the summer monsoon. Of these two, spring propose making artificial snow to augment the in- snowmelt provides most of the water that re- termittently occurring natural snow in the winter. charges the groundwater system. This is so be- The proposal includes a plan to use up to 1.5 cause more infiltration and groundwater recharge million gallons of reclaimed water per day fromoccur in the winter and early spring months when November to the end of February whenever snowthe ground is saturated with snowmelt, and there deficiency occurs. The use of reclaimed water for is a prolonged period of minimal evapotranspira- snowmaking is a common practice at several ski tion loss. Summer recharge is generally from in- areas; for example, two ski areas that use re-tense thunderstorms that produce runoff into claimed water for snowmaking are Bear Mountain streams, solution channels, and sinkholes that in California and Whitetail in Pennsylvania. Cur- direct the water rapidly into the ground. However, rently, the main demand for reclaimed water high evapotranspiration rates in the summer limit during the spring and summer months in Flagstaff the amount of water that reaches the water table is for watering golf courses, cemeteries, private during less intense precipitation events (Bills et al. homes, and city parks. However, during the win- 2000). Precipitation increases with elevation. At ter months, the reclaimed water from the Rio de higher elevations such as on the San Francisco Flag Wastewater Treatment Plant is released into Peaks, 30 inches of precipitation per year is corn - the Rio de Flag, where it travels approximately 2 mon (Gavin 1998). The south and west flanks of miles downstream before it disappears into the the San Francisco Peaks are headwaters to the Rio ground. de Flag and Volunteer Wash. Most of Snowbowl ski area lies within the headwaters of Volunteer I School of Forestry, Northern Arizona University Wash. Most of the runoff from snowmelt and 48 Leao and Tecle To Grand Canyon FLAGSTAFF GRßIC CENTER ARIZONA SNCA+YBQWL SKI LIFT# LODGE Figure 1. Location of Arizona Snowbowl. (Source: Arizona Snowbowl) intense rains flows in a southwesterly direction of 200 feet below the ground's surface in the through the Bellemont area to join Sycamore Can- Snowbowl area. Otherwise, the regional aquifer is yon, which is one of the tributaries of the Verde located several thousand feet (depending on land River. Only a small portion of the Snowbowl ski surface elevation from 3000 to 5000 feet) below the area lies within the headwaters of the Rio de Flag. surface along the flanks of the San Francisco Peaks. The Rio de Flag flows in a southerly direction On the surface the dominant soils in the Snowbowl through Flagstaff before it turns eastward to join area are sandy loam, which can be considered well Walnut Canyon to form San Francisco Wash. Sandrained. Permeability of these soils ranges from Francisco Wash then flows into Canyon Diablo, 0.06 inches per hourr to 1.98 in /hr (Gavin 1998). which eventually drains into the Little Colorado The soils and moisture regime in the area support River. a wide range of vegetation types, which change The geology of the Snowbowl area is complex with elevation. From 7000 feet to 12,633 feet, the because the San Francisco Peaks are erosional vegetation consists of pine, aspen, mixed conifer, remnants of a compound stratovolcano with lava and alpine tundra forest types. domes. Since the creation of the San Francisco Peaks during the late Pliocene, approximately 7.5 IMPORTANCE OF THE miles of rhyolite, dacite, and andesite have been SAN FRANCISCO PEAKS erupted (Holm 1987). The presence of multiple The San Francisco Peaks are valuable for recrea- embedded layers of dense (basalt) and porous tion, research, sources of industrial materials, (cinders) volcanic formations gives rise to several domestic water supply, and cultural heritage. Rec- perched water -bearing zones at minimum depths reationists use the mountains for hiking, camping, Impacts of Snowmaking in Flagstaff 49 backpacking, wildlife viewing, and skiing. Re- ply from the storage tank in Thorpe Park, located searchers use it to study wildfire occurrences, con- in northwest Flagstaff. Starting at a pumping trol and management, and ecological succession station at Thorpe Park, the water supply pipeline with elevation, and to learn about the mountainwould run northwest across Observatory Mesa and its various components. Industry uses the area along existing forest roads where it would connect as a source of pumice to wash denim and to make with an existing clearing for a natural gas pipeline cement blocks. The mountains are also important that crosses Snowbowl Road. It would then follow for the city of Flagstaff as the source of water and the road up to the ski area. In addition three boos- recharge area for the city's water supply wells. ter pumping stations may be installed at strategic Native Americans use the mountains for religious locations along the pipeline. When the water ceremonies and to gather medicinal native plants reaches Snowbowl, a 10 million gallon water stor- (Land Use History of the Colorado Plateau 2002). age pond would be required to store the reclaimed At the base of the San Francisco Peaks are nu- water and to ensure operational efficiency of the merous wells used as sources of water for private snowmaking process (Coconino National Forest residences and nine wells used as sources of water 2002). Considering the high infiltration rate of the for the city. Because the geology is complex, wells soils in the ski area, the storage pond would need used for private residences range anywhere from to be lined with an impervious material. The 50 to 1000 feet deep. The city wells, which are stored water could also be used for fire suppres- located in the Inner Basin on the northwest aspect sion. of the Peaks, range from 400 to 600 feet deep. In Two main types of snowmaking "guns" would the late 1950s the Snowbowl ski area attempted be used to disperse the artificial snow onto the ski but failed to drill a well for a source of domesticruns. On the lower slopes airless fan guns would water supply (D. J. Bills, USGS hydrologist, per- be used, and on the upper slopes, air /water tower sonal communication 2002). guns would be used. Airless guns are generally mounted on towers or sleds that are towed behind SNOWMAKING REQUIREMENTS a snow cat. They spray water out of nozzles while According to Wingle (1994), installing snow- an electrically powered fan disrupts the water into making facilities requires prior comprehensive small droplets that are propelled into the air. planning to ensure efficient water use, to under- Standard air /water guns use nozzles in which a stand the wind patterns that can affect snow stream of water is internally interrupted by a jet of deposition, to secure skier safety, and to minimize compressed air that creates small water droplets. installation costs and land disturbance in the To avoid collision and ensure safety, it is impor- process. As a result, proper planning for snow- tant to locate snowmaking guns and towers away making involves identifying and understanding from the direct paths of skiers (American Skiing such elements as sources of water supply, snow-Company 2003). In addition to installing a buried making infrastructure, and weather patterns.