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HomeMy WebLinkAboutcoa.lu.pu.Aspen Mountain master plan 1997v 4D 1 9 9 i Aspen Mountain Master Plan August 1, 1997 Revegetation Plans Photo of Aspen Mountain circa 1958 courtesy of Apen Historical Society Memorandum To: Brent Gardner -Smith, Planner For Community Affairs From: John H. Sale, Planner Date: 08/01 /97 Re: AMMP Re -Vegetation Plan, Vegetation Management Per, the County's request, I have included the Aspen Mountain Re -Vegetation Plan including an illustration of the proposed sites. Most of these practices are in full implementation at this time. • Page 1 Aspen Mountain Re -vegetation Plan This re -vegetation plan is designed to satisfy the requirements of both the U.S. Forest and Pitkin County. Aspen Mountain has a long history of successful re -vegetation efforts. Knowledge acquired over the years on site will be applied to all aspects of implementing our re - vegetation plan. Due to the mining history and the industrialized conditions that were left behind, Aspen Mountain must take a very unique approach to its re -vegetation plan. Considering that there is very little nutrient top soil available on the mountain, the degree of success for re -vegetation must be evaluated differently than other ski areas. Problem areas targeted for re -vegetation will be classified into one of the three categories below. Category I Problem areas that fall within this category are typically "cosmetic" repairs. Generally, this includes previously seeded areas that need additional seeding or the seeding and mulching of patch areas. The procedure for this category include seeding, mulching and the application of an organic fertilizer. Example: An exemplary site of Category I would be the Spar Gulch area. Overall this area is well vegetated, although there are many patches and bare spots noticeable in high visibility areas. Category II Areas that fall into this category are light erosion zones, previous construction sites, and compacted bare spots. While these areas are not critically serious they may need some mechanical equipment to properly re -vegetate the area. The procedure for this category include scarifying the soil, seeding and apply organic fertilizer, and mulching. Additional top dressing may be needed to properly re -vegetate the area. Example: A prime example of Category II would be the area surrounding the base of the Shadow Mountain Lift (# 1-A). This area needs more attention and because it is a high use area for both foot and vehicle traffic. The soil needs to be scarified and top dressing will provide the nutrients and base for the seed mix. Category III Problem areas that fall into this category are site intensive and are serious undertakings. Many of these areas will include re -grading and large quantities of soil, and structural support may be required for stabilization. Procedures for this area will require re -grading of terrain, hauling of additional top soil, seeding and mulching and application of organic fertilizer. Example: One project slated for Category III would be the slope of the Little Nell Hotel that faces the Gondola terminal at the base of Aspen Mountain. Although this area would be typically considered Category I, we feel that due to its visual exposure, a total re-veg project would be most beneficial to the enhancement of the community. This site would require a small irrigation system and the import of top soil to provide a home to a mass planting of Colorado wild flowers. *See figure 18, Re -Vegetation Plan of the 1997 Aspen Mountain Master Plan. This figure graphically illustrates the location of problem sites and are broken down into the three categories described above. The Aspen Skiing Company proposes to take on one extensive re -vegetation problem area per year. The selected area, depending on which category the area falls into will be completed within the summer months. Each selected area will vary in size and complexity, one year may cover a large area of Category I and the next year a small but intense Category III area. ASC wishes to address the issue of re -vegetation head on and commit the resources needed to implement a working plan. At this time the Aspen Skiing Company is engaged in extensive Vegetation Management Plans for both the Aspen Highlands and the Snowmass Ski Area. These studies are being conducted by Western Bionomics, LLC. of Ft. Collins, Colorado with the approval of the White River Forest Service. ASC is preparing to study Aspen Mountain and Buttermilk in the 1998 fiscal year. The scope of work will address a total Vegetation Management Plan and will include timber re -vegetation and clearing. The vegetation management plan will be coordinated with a 1993 study prepared by the Wildlife Habitat Enhancement Council entitled "Opportunities for the Enhancement of Wildlife Habitat and Environmental Awareness on Aspen Mountain." Re -vegetation of the disturbed sites on Aspen Mountain will have four primary goals: 1. prevent soil loss and siltation of drainage as a result of removing forest cover; 2. establish vegetation that is compatible with existing native vegetation in appearance, composition, and permanence; 3. creating habitat that will support use by native wildlife; and 4. to provide quality skiing terrain. These goals will be accomplished by planting native grasses or species adapted to the area and using mulch to reduce soil loss and enhance the establishment of seeding. In areas with steep slopes and shallow or erodible soils, mulch will be used in combination with an erosion control mat or netting to provide further protection of soils and seedlings. Follow-up measures, such as additional seeding and/or fertilization, will be applied as needed. These measures conform to the Pitkin County Landscape Guidelines, which have been incorporated where appropriate throughout this revegetation plan. The native seed mixes listed below have been selected to provide visual diversity, prevention of soil erosion and ensure that a variety of feed materials are available throughout the growing season. Aspen Mountain Mix Name, Variety Percent Streambank Wheatgrass, Sodar 5% Slender Wheatgrass 5% Tall Fescue 10% Hard Fescue 10% Creeping Red Fescue 10% Mountain Bromegrass 15% Orchardgrass, Paiute 10% Canada Bluegrass 10% Alsike Clover 5% White Dutch Clover 5% Timothy, Climas 10% Red Top 5% *Fertilizer biosol or other suitable organic fertilizer only. No nitrogen fertilizer will be used. All seed will be furnished from Garrison Seed Company. The seed bags have the appropriate information (name and address of the supplier, the seed names, the lot number, net weight, origin, percent weed content, the guaranteed percentage of purity and germination, and the pounds of pure live seed of each seed species) on them. All supplied seed will be free of noxious weed seeds. A signed statement certifying that the seed furnished is from a lot that has been tested will be made available. Seed, that has become wet, moldy or otherwise damaged in transit or in storage will not be used. During the process of clearing sites, both rubber -tired and tracked equipment will be used on slopes of 30 percent or less. On steeper slopes, only tracked equipment will be used. Damaged areas will be regraded to appropriate smoothness and patched with soil material, if necessary. Seeding Procedure: Seedbed preparation will consist of leaving a rough, irregular soil surface. This will include removing large rocks. Regardless of the mix of seed used, seed will be planted by broadcasting or drill seeding within ten days after soil disturbing activity has ended. Toward the end of the construction season, all areas will be evaluated and additional revegetation measures will be implemented as needed. Planting during the early fall will allow the seed to be fully moistened and worked into the soil by natural processes prior to germination in the spring. For some species, overwintering also enhances germination by weakening the seed coat. Seeding rates will vary because of seed size, method of seeding and site requirements. Seeding rates of 50 to 250 seeds per square foot, depending on seed size, will be used. Available plant nutrients are a necessity for any aggressive revegetation program that restores and maintains soil productivity resulting in healthy, vigorous vegetation. Generally, all vegetation responds favorably to the addition of nitrogen and phosphorus fertilizers. A mixture of 20-20-10 will be used as a supplement to assist revegetation. An application rate of 50 to 250 seeds per square foot followed by a second application of equal amount later in the growing season or the following growing season has been demonstrated to be most effective and efficient. The U.S. Forest Service will assist in the designation of additional control measures, if any are needed. These measures may include, but are not limited to silt fencing, sediment basins, check dams, berms, mulching, revegetation, or natural materials will be used to decrease energy and remove silt. Mulching Procedure: Following seeding slopes with steepness less than 2:1 will be mulched with approximately 1,500 pounds per acre of straw. This straw or hay will provide the cover needed while still allowing sunlight to penetrate the mulch, warming the soil and enhancing plant growth. Application is done either by hand placing or mechanically blowing the mulch. The straw will be crimped into the soil and, in areas subject to wind erosion, anchored with a tackifier. Areas with steepness greater than 2:1 will be further stabilizer by using plastic netting or mat. A standard of 70 percent ground cover after the second growing season or the amount equal to the adjoining undisturbed areas, if less than 70 percent will be used to determine reapplication, modification, or fertilization. The Forest Service will also monitor ASC's compliance with the re -vegetation specifications contained in the annual Summer Operating Plan. Reclamation Areas that will be reclaimed are building sites, structure placements, and landforms that will be moved, replaced or abandoned. Reclamation will consist of minor disturbances from grading the previously developed areas into the natural contours and revegetating. Appropriate and revegetation will occur within ten days after construction activities on site have been completed. Aspen Mountain Erosion Control Plan Aspen Mountain erosion and drainage plan was designed to protect the natural resources in the project areas. (There are no active year-round streams in the area, but there are two main drainages that are active in the run-off period and have the potential to cause erosion. Currently, both are culverted where necessary and are well managed. The plan consists of, for the most part, two measures. The first is the use of silt fences and erosion bales located at the toe of disturbed sites during the construction activities. The second control measure is an aggressive revegetation program described in the Revegetation Plan. Seeding and mulching will be enacted within ten days after the completion of the soil disturbing or construction activity. The specific erosion control measures are detailed on the revegetation and drainage plans. Other erosion control measures will be used throughout the area as needed. One specific measure is water bars. They will be installed at appropriate intervals along cleared ski slopes and roads to limit distance that sheet runoff can flow unchecked. The water bars will divert runoff into the adjacent uncleared forest whenever possible. Where appropriate, energy -dissipating structures (i.e., rock, hay bales, or slash piles) will be installed to prevent erosion in the forest areas receiving the diverted slope runoff. ASPEN MOUNTAIN SKI AREA -.L $ m 7g N Rim ® ]L- ® ]Ei. -1• .- 7L? -C3 1997 Master Plan Fianre 18 Re-Vesetation Plan D.e.a A.ao�E 1997 9o.l.i 1" , 1000• Cvntoue I.E+z�.J t 20. AWSH armNo OOIrPAN! N.=t4 suu• a 40qr aar 1 9 9 7 Aspen Mountain Master Plan August 1, 1997 Snowmaking Analysis Photo of Aspen Mountain circa 1958 courtesy of Apen Historical Society AUG 01 '97f 11:53AM L R " W E P.2 PRELIMINARY REPORT ON THE POTENTIAL IMPACT OF NEW SNOWMAKLNG AT ASPEN MOUNTAIN For Aspen Skiing Company Leonard Rice Consulting Water Engineers, Inc. August 1, 1997 AUG 01 197 11:53AM L F P.3 ACKNOWLEDGMTE1vTS The technical material in this report titled, "Preliminary Report on the Potential Impact of New Snowmaking at Aspen Mountain," dated August 1, 1997 was prepared by or under the supervision and direction of the undersigned whose seal as a Professional Engineer is affixed below: Leslie H. Botham, P.L. The following members of the Leonard Rice Consulting Water Engineers, Inc. WE contributed to the preparation of this report: Principal Investigator: Hydrologist: Technician: Technical Typist: Leslie H. Botham Jennifer Larson K4a Stringfield Glenda Emmans Leonard Rice Consulting Water Engineers; Inc. HUG 01 ' 97 11: 54AI I L R - 1 _ o . 4 PRELLNUN ARY REPORT ON THE POTENTIAL IMPACT OF NEW SNOWMAIK NG AT ASPEN MOUNTAIN August 1, 1997 INTROIDUCTION The Aspen Skiing Company (ASC) proposes to increase the size of its snowmaking area on Aspen Mountain by approximately 56 acres. It now makes snow on about 180 acres. The new area is located above (south of the existing snowmaking area, lying between elevation 10,370 and 11,180 feet, in Pitkin County, Colorado. The area is shown on Figure 1, and it is about 2.1 miles south of the City of Aspen. ASC estimates that it will deliver an average of 11 million gallons of water to the new snowmaking area per year, which will make about 18 inches of snow in November and December of most years. The purpose of this preliminary report is to qualitatively address the impacts that the proposed new snowmaking activity could have on storm runoff from the Aspen Mountain. BACKGROUND It is reported that ASC has been in, aking snow on Aspen )Vuntain since 1983. Table 1 summarizes the amount of water which has been used in recent years to make snow on approximately 180 acres of trails and ski runs. The average water applied is 0.198 million gallons (MG) per acre, with a range from 0.102 to 0.297 MG per acre. With specific regard to the Summer Ditch, which exports water from Spar Gulch c Keno Gulch, Wright Water Engineers, Inc. concluded in 1989 that ASC's snowmaking activities above the ditch ".., would increase snowmelt runoff and the diversion rate by approximately three percent." APPROACH Because of the limited time available for this study, it was necessary to make maximum use of existing information and to conduct qualitative investigations. For Spar Gulch and its tributaries, we were able to obtain and review two drainage studies: a) "City of Aspen, Urban Runoff Management Plan," by Wright-IvlcLaughiin Engineers, August 1973, and b) the more recent "Aspen Mountain Lodge, 700 South Galena Street, Top of Hill and Ute City Place, Storm Drainage Report,"by Rea, Cassens and Associates, Inc., July 1985. These reports identify the 2-year, 5-year, and 100-year storm flows for Spar Gulch, which contains the majority of the new snowmaking area. These values are summarized on Table 2. Leonard Rice Consulting Water Engineers, Inc. AUG 01 "?i 1i:54AM L R P.c Preliminary Report on the Potential Impact of New Snowmaking August 1, 1997 Page 2 For Keno Gulch, we were able to obtain and review the draft report "Report on the Aspen Music School Debris Flow Investigation," by Wright Water Engineers, Inc., May 1996. Several approaches were undertaken for this investigation. The first was to quantify the water equivalent of the snow to be added to Aspen Mountain, and compare it with estimates of historic water equivalent of the snow on the mountain, as indicated from historical "Snotel" snow course station data. The second approach was to compute the average rates of flow which could result if the water equivalent of the new snow was released from the mountain for a range of durations from one to 45 days. The results were th;,n compared to published estimates of storm runoff for the mountain. The third approach was to utilize the methodology developed by Colorado S!d Col itry USA to compute the amount of runoff from the new artificial snow. The procedure is contained ii a report titled "A Final Report on The Colorado Ski Country USA Water Management Research Project," February 1986. The report has separately a bound "Handbook" and an "Appendices" of the same date. TRIBUTARY AREAS In this analysis, the areas of interest are defined as Spar Gulch and its tributaries (which deliver water from Aspen Mountain to the City of Aspen) and Keno Gulch which is above .he Music School. The 56 acres of new snowmaking area occupy about 124 acres of Im-id. In, other words, new artificial snow ,will ;;e ?made will be on ski tmiis and ski runs which themselves are within the larger area of about 124 acres. Of the 56 acres of land, nine acres wrill be exported out of the area of interest to the east, and another 4.6 acres will drain out of the area to the southwest. Two acres wl drain to Copper Gulch, which is tributary to Spar Gulch, and the remaining 40.4 acres drain ;o the "Summer Ditch," an interceptor ditch which exports Spar Gulch flows into Keno Gulch, which is located to the west. See Table 3 and Figure 2. At the point where the Summer Ditch delivers water into the Keno Gulch basin, it is approximately 500 feet north or a. landslide and debris flow which affected the Aspen Music School in May 1996. In its report, "Report on the Aspen Music School Debris Flow Investigation," May 1996, Wright Water Engineers, Inc. concluded on page 14, "... although the }Spar Gulch diversion water may have increased the fluidity of the marerial, it was not the cause of the landslide or debris flow." Figure 1 and 3 of. the WWE study show the relation of the landslide area to the diversion ditch, and WWE's conclusions are included with the Backup for this report. Leonard Rice Consulting Water Engineers, Inc. Preliminary Report on the Potential Impact of New Snowmaking August 1, 1997 Page 3 If the Sumner Ditch is considered fully effective, then the 40.4 acres of new snow area tributary to it constitute 8.1 percent of the 502 acre tributary area of the Summer Ditch and Keno Gulch. See Figure 3. If the capacity of the Summer Ditch was exceeded or if it failed, then runoff above it would remain in the Spar Gulch basin and continue down Spar Gulch toward the City of Aspen. Therefore, the other point of view in this report neglects the capacity of the Summer Ditch. In that case, 42.4 acres of new snow area (40.4 acres above the Summer Ditch 2.0 acres tributary to Copper Gulch) constitute 6.3 percent of the 657-acre combined Spar -Copper -Vallejo Gulch tributary area above the City of Aspen. The two existing drainage studies mentioned above also disregard the interceptor ditch. See Figure 4. WATER EQUIVALENT OF NEW SNOW ASC estL-iates that it will use an average of l i MG of water :o rrakz artificial snow on the new area. This is equivalent to 7.23 inches of water over the 56 acres of new snow area. Based on iustoric operations, we estimate that the amcum applied :night range from j.7 to 16.6 MG (see Table 1). The spray losses from the initial application are estimated to be 6 percent. Sc the water Nuivaient of'he artificial snow which will be made is estimated to average 10.34 MG (6.30 inches), with a range from 5.4 to :5.6 MG. Tables 4 and 5 and Figures 5 and 6 summarize the historical water equivalent of two SCS snow survey (Snotel) stations on Aspen "Yfountain. They are earned ":aspen." and "Lift." The Aspen gage was located near lift 3 at an elevation of about 9,700 feet. 1t was discontinued in 1984. T ae Lift gage is located east of the Sun Deck at an elevation of 1,250 feet. The data presented on Tables 4 and 5, and on Figures 5 and 6 show the water equivalent of the snow on :he ground on the first days of February. March, April, and May for the years which we had readily available information. For the Aspen gage, the range of water equivalent is from 2.3 to 26.7 inches. The average values range from 9.9 inches on February 1st to 18.2 inches on May 1st. For the Lift gage, the range is from 2.9 to 33 inches, with the averages ranging from 11.3 to 20.2 inches. The average water equivalent of the new snow (after deducting 6% for spray loss) is estimated to be 0.57 feet or 6.80 inches over the 56 acres of new snowmaking area. Expressed over the whole 502- acre tributary area of Summer Ditch and Deno Gulch, this is equivalent to 0,55 inches. See Table 6. This is from 3.0 to 5.6 percent of the historical average first -of -month (February through May) water equivalent for the Aspen snow gage, and from 2.7 to 4.9 percent for the Lift gage. The water equivalent of the new snow when expressed over the 657-acre tributary area of Spar, Copper, and Vallejo Gulches, is equivalent to 0.44 inches. See Table 6. This is from 2.4 to 4.4 percent of the average monthly (February through May) water equivalent for the Asper. snow gage, and from 2.2 to 3.9 percent for the Lift gage. Loonard Rice Consulting Water Engineers, Inc, AUG 2 ­�7 7 Preliminary Report on the Potential Impact of New Snowmaking August 1, 1997 Page 4 The Spar-Gulch-equivaient estimate is shown on Figures 5 and 6 for comparison with the historical water equivalent of snow on the mountain. Since the water equivalent of the new snow is such a small percentage of the snow which is already on the mountain, the effect of the new snow is expected to be negligible in terms of contributing to the storm runoff which will be expected in either Spar Gulch or Keno Gulch. POSSIBLE SNOW -MELT RATES We also computed the average rates of flow which might result if the water equivalent of the new snow melted without any additional loss (like evapotranspiration or percolation) over periods of time ranging from one day to 45 days. The results are shown on Table 7 and on Figure 7. For any given duration, these rates of snowmelt would be conservative, since other ,osses would occur like sublimation, infiltration, and evapotranspiration. ASC representatives estimate that under normal conditions it would take about 7 days to melt 18 inches of snow at the altitude of the new snow area. Using this as a representative time, the rates of snowmelt are estimated to be 1.65 cfs to 2.49 cfs for the Keno Gulch area, and 1.73 to 2.67 cfs for the Spar Gulch area. See Table 7. The published storm ranoff amounts for Spar Gulch, and the estimated amounts for the Summer Ditch tributary area and Keno Gulch are summarized on Table 2. The estimates are based on the per -acre values for Spar Gulch. Considering the limiting culverts at the end of the Summer Ditch as it exits the Spar Gulch basin (ie the 18-inch and 12-inch corrugated metal culverts), we estimate the capacity of the Summer Ditch diversion at less than 7 cfs, which is the estimated 2-year storm inflow. The capacity of the ditch itself is much more than this in most areas. The various maximum -year snowmelt rates for the Spar Gulch analysis are compared with the 2-year and 5-year storm runoff values for Spar Gulch on Figure 8. From this analysis, it is clear that the snowmelt rates from the new snow are well below even the 2- year storm runoff values for Spar Gulch, or the combined Summer Ditch and Keno Gulch basin. EXPECTED RUNOFF FROM NEW SNOW Using the procedure outlined in the Handbook from the report "A Final Report on The Colorado Ski Country USA Water Management Research Project," February 1986, we estimated the volume and monthly distribution of runoff from the new snow. The average water applied amounts to 7.23 inches over the 56 acres of new snow area. The 6% initial spray loss amounts to 0.43 inches of water. Prior to and during runoff an additional 1.25 inches of loss are expected. This leaves an expected total Leonard Rice Consulting Water Engineers, Inc. Preliminary report on the Potential Impact of New Snowmaking August 1, 1997 Page S rzuloff amount of 5. 5 inches. The component parts are shown on Figure 9. Additional losses would be expected as the runoff travels down the mountain via Spar Gulch, or through the Summer Ditch and down Keno Gulch. The runoff pattern is expected to occur during April through. June. Figure 10 shows the rates of flow which wouid resuit just below the 40.4 acres of new snow area above the Summer Ditch. The average monthly rates of flow peak in April at 0.30 efs. Since this is well within --ye capacity of the Summer Ditch, we would expect .hat it would be conveyed to Keno Gulch. However, the ditch itself would be expected to leak, and there would be additional losses due to evapotranspiration along the ditch and within the Keno Gulch basin, so the peak flow at the mouth of Keno Gulch would be less than 0.30 cs. The expected timing of runcff just beiow the V vo acres of new snow area which are tributary to Copper Gulch we shown on Figure 11. The flow would peak in Apr:'] at 0,015 cfs. Additional losses would be expected to occur during the flow path down Copper Gulch. This is a very small (negligible) rate of flow, which may not even make it to +he confluence of Copper and Spar Gulches, let alone the mouth of Spar Gulch at the City of Aspen. OTHER CONSIDERATIONS It is believed t At the storm runoff which will occur from Aspen Mo,.ntain will be generated by -.1i=derstcrru rainfall, rather than from s=xynelt. This is addressed in the 1973 Wright -McLaughlin master plan, which shows :hat rainfall runoff is much grreate. than the snowmelt runoff for selected areas. Thunderstorms are expected to occur in mid to late summer, after most of the snow has melted. It is also clear from the above analysis that the majority of the runoff from the new snout will occur during April, which is much earlier in the year. It is, however, possible for rainfall events to occur when snow is still on the ground. When this happens, the rain helps melt some of the snow, which then contributes to the runoff. The new snow will be among the first snow on the mountain. If a rainfall storm happened when there was plenty of snow on the mountain (several feet for example), then the new snow would not make any difference in the amount of runoff, since the snow on the top would be affected by the rainfall. If the rainfall storm happened when there was not much snow on the ground, then it is possible that the new snow could make a difference in the amount of runoff which would occur. It is likely that the added snow will increase the time that snow is on the ground by a few days to possibly a week. This increases slightly the time that rain -on -snow storm events could occur. Leonard Rice Consulting Water Engineers, Inc. qUG 01 '9 111:SrAM L R E P.9 Preliminary Report on the Potential Impact of New Snowmaking August 1, 1997 Page 6 CONCLUSION From the above qualitative analyses, we believe that the 56 acres of new artificial snow which is proposed by ASC will not have any significant effect on the runoff from the Aspen Mountain, either in the Spar Gulch basin, or the Keno Gulch basin. File: SNOWNMLT.RPT Attachments: LRCWE Tables 1 through 7, LRCWE Figures I though 11, and LRCWE Backup (24 pages). Leonard Rice Consulting Water Engineers, Inc. AUG 01 ' 9'7 11: 5 7AM L 1 E P . 10 Aspen Skiing Company Preliminary Table 1 Estimate of Water Used for Existing Snowmaking Operations On Aspen Mountain Less Remainder November Water, Average Use Assumed for Projected Through ' Purchased a Ruthie's Snowmaking on Snowmaking on , January i From Aspen' Restaurant�'80 EXISTING ACRES 56 NEW ACRES l iN i; i i on G a !Ions MG/Acre Million Gallons) 1983-34 18.650 -0.276 18.374 0.102 5.716 1984-85 19.560 -0,276 19.284 0.107 5.999 ' 1985.86 28.816 -0.276 28.540 0.159 8.879 1988-87 30,222 -0,278 29.946 0.168 9.317 1987-88 38.250 -0.276 37.974 0.21.1 11.8141 1988_�9 37.740 -0.275 37,470 0,208 11,657 1989-90 52,992 -0.276 52.716 0.293 16.4011 1990-91 39.548 -0.276 39.270 0,218 12.217.. 1991-92 40.738 -0.276 40.482 0.225 12.5881 1992-93 45.996 -0.276 45,720 0,254 14.2241 i 1992-a4 53,710 -0.276 53.434 0.297 t 16.624` 1994-a5 24.372 -0.276 24.396 0.138 7.590I 1995.96 37.313 -0.276 37.337 -.1207 11.616 99647 34.118 -0.276 33.840 0.188 10.528 Aver -age 35.902 -0.276 35.826 0.198 11.084 Maximum 53.710 -0,276 53.434 0.297 16.62_4, Minimum 18 650 -0.275 18.374 0.102 5.716 Notes, Constants, ar,d Calcu!ations: 01-Nov First day for restaurant's water use 31-Jan Last day for restaurants water use 92 Days for restaurant water use 30,000 Gallons used for restaurant use every 10 days. 180 Acres of existing snowmaking area 56 Acres of new snowmaking area = 34,01 AcFt = 51.02 AcFt 17.54 AcFt July 30, 1997 Leonard Rice Consulting Water Engineers, Inc. ( Printed 31-Jul-97) Fite: Snow RO.W81 AUG 131 ' 37 11: 58AM '_ R Aspen Skiing Company Preliminary Table 2 Summary of Reported & Estimated Storm Runoff Amounts July 30, 1997 Tributary 2-Year Runoff 5-Year Runoff 100-Year Runoff Basin IC & Description Engineer Year Area ;Acres) (Cr8) (AcFt) (CFS) I (AcFt) (CFS) (AcFt) i 1A (Spar Gulch a Elev 8,^00') Wright -McLaughlin (a) 1973 590 22 3.1 302 27A ,B&C `Copper & Spar GulcheS) Rea-Cassens (b) 1985 551.8 10.2 32.6 195.4 ,B,C,D,&E (Spar (§ L Nell) Rea-Cassens (b) 1985 679.3 15.5 46.0 314.9 Kero Gulch Natural Basin L RCWE (c) 1997 254 8 17 124 Summer Gulch Intercepted Area LRC'NE (c) 1997 248 7 17 121 ;a) "City of aspen, Urban Runoff Management Plan," August 1973. b) "Aspen Mountain .Odge, 700 South 3alana Street, Top of Mili and Ut3 City place, Storm Water Drainage Repor.," .January 1 W. (c) Very preiiminary estimate by Leonam Rice Consulting Water Engineers based on unit values by Wright -McLaughlin & Rea-Cassens. Leonard Rice Consulting Water Engineers, Inc. ( Printed 31•Jul-97 ) tile: Snow RO.WB1 AUG 01 '97 11:58AM L R E Aspen Skiing Company Preliminary Table 3 Summary of TributaryAreas (Acres): Percent of Total Keno Gulch at Castle Creek- 254 Natural tributary area 50.60% 248 imported from Spar Gulch via Summer Ditch 49.40% -502 Total 100.000/0 Spar; Copper, and Vallejo Gulches- 183 Copper Gulch's tributary area 27.85% 344 Natural tributary of Spar G above Copper G 52.38% 83 Spar Gulch below Copper G, at Little Nell Run 12.63% 47 Silver Queen Area at Little Nell Run 7.15% 657 Total Spar and Copper Gulches 98.99% -248 Spar G exported to Keno G via Summer D 409 Total Spar & Copper',ess exported Summer C Snowmaking Area- 3.0 Out of Basin to the East 16.07% 4.8 Out of Basin to the Southwest 8.21 % 2.0 Tributary to Copper Guich 3.57% 40.4 Tributary to Spar Guich & Summer Ditch 72.14% 56 Total 99.99% 56 Check against acres of new snowriak;ng area 124,5 Area that the b6 acres of new snowmaxing occupies New i 4.0 Export to SW 2.0 To Copper Gulch 40,4 To Summer D & Spar G 56 Where it Drai Soar Gulch Tributary Area Bar Graph- 8.21 % 3.57% 72.14% 42-4 New SnowmaKing t5.40'/6 614.6 Below New Snow 93.55% 657 567.0 Total of Parts 100,00% Total at Littl Component Parts Keno Gulch Tributary Area Bar Graph: 4u.4 impoRec New z)now o•uv io 207.6 Imported beiow New Snow 41.35% 254.0 Natural Basin 50.60% 502 arts cz1ie Component Parts July 30, 1997 Leonard Rice Consulting Water Engineers, Inc. ( Printed 31-Jul-97 ) File: Snow RO,WB1 BUG 01 '97 11:59AM L ? E Asper Skiing Company Preliminary July 30, 1997 Table 4 Historical Snow Course (Snowtel) Data for Aspen Mountain- Gage Named "Aspen" (a) For Compared with Water Equivalent of New Snow Over Spar Gulch Basin Comparison, Average Water February 1 Report March 1 Report i April 1 Report May 1 Report Equivalent of New Snow Over Snow Water Snow Water i Snow Water Snow Depth Water Equivalent Spar Gulch Basin 'ear i Date Oepth Equvvaien Date Depth Equivalen Date i Depth Equivalentl Date j k ,tnches) ; (Inches) i i Inches) (Inches) Inches) (inches) i (inches) (Inches) (Inches) 1960 1-26 30 8.3 2-25 59 17.4 3-25 71 19.6 4.28 53 18.3 0.44 � 1961 1-25 25 4, 8 2-25 34 8.8 3-25 45 10.1 4-26 48 15.5 0.44 1962 1.26 55 13.7 2-25 83 16A 3-25 88 22.4 4-26 Be 20.9 0.44! 1963 1-26 24 4.1 2-23 34 7.5 3-30 38 10.8 4-24 34 10.5 0.441 1984 1-25 32 8.4 2-22 38 9.1 3-22 48 12.2 4-27 45 12.8 0.44 t965 1-28 51 14,5 2.26 55 18.5 3.29 95 25.1 4.27 76 23.5 0.44 19M 1-23 35 9.4 2-25 41 10.6 3-28 41 12.0 4-27 38 12.0 0.44 1967 1-29 44 10.0 2-27 57 17.5 3-29 49 18.8 4-28 45 16.1 0.44 1968 1-29 36 8.5 2-26 47 12.3 2-29 48 13.1 4-28 66 20.8 0.44 1969 1-28 64 12.5 2-26 52 16.4 3.29 56 18.2 4-27 42 19.0 0.44 1970 1-28 45 13.0 2-25 52 13.8 3-29 51 13.0 4-25 72 28.7 0.44 1971 1-28 41 12.3 226 81 19.8 3-29 70 24.9 4-28 56 17.9 0.44 1972 1-28 44 12.3 2-28 51 15.4 3-28 51 16.7 4-28 53 21.7 0.44 1973 1-28 41 11.4 2.26 42 12.2 3.27 54 17.7 4-28 59 21.0 0.44 1974 1-28 51 13.4 2-25 54 15.7 3-29 39 19.9 4-28 60 24.7 0.44 1975 1-28 46 10.9 2-25 =2 14.7 3-28 72 21.4 4-28 81 21.6 0.44 1976 1-28 40 10.3 2-25 54 16.0 3-28 55 18,7 4-27 S5 23.0 0.44 197 7 1.27 20 2.3 2-25 30 5.8 3-29 45 12.0 4-28 24 3.5 0.44 1978 1-23 50 14.4 2-25 52 418.1 3-28 71 26.7 NS 0.44 1979 1.26 53 15.2 2-24 57 16.8 3-28 54 17.4 4-27 52 18.5 0.44 1980 1-27 35 8.1 2-26 56 4.0 3-26 58 18.4 4-28 53 19.0 0.44 1981 1-26 15 3.3 2-23 22 4.9 3-26 35 8.7 4-25 31 10.4 0.44 1982 1-26 46 12.8 2-24 48 15.2 3-26 58 12.4 4-28 59 22.2 0.44 1983 1-24 28 6.6 2-23 38 3.8 3-25 58 19.4 4-25 58 18.4 0.44 1984 Gage Discontinued verage 39.6 9.9 47.9 '.3.4 584 17.8 52.3 18.2 Maximum 64 15.2 63 19.8 95 26.7 76 28.7 Minimum 15 2.3 22 4.9 35 8.7 24 8.5 Avg '63-'77 41 10.1 48 13.7 55 17.3 52 18.4 Avg '80-'77 40 9.9 49 13.7 56 17.3 53 18.3 (a) SCS Gage "Aspen" -- Colorado River Basin (Roaring Fork) Gage No. 031<22, Lat 39 Deg 9 Min, Long 106 Deg 49 Min. Located on Aspen Mountain at Ski Lift Number 3, Sec 7, T11 S, R84W, elevation 9,700 feet. Leonard Rice Consulting Water Engineers, Inc. ( Printed 31-Jul-97 ) He: Snow_RO.WB1 PUG 01 '97 11:59AM L - Aspen Skiing Company Preliminary July 30, 1997 Year 'able 5 Historical Snow Course (Snowtel) Data for Aspen Mountain- Gage Name "Lift" (a) ' For Compared with Water Equivalent of New Snow Over Spar Gulch Basin Comparison, Average Water February 1 Report j March 1 Report ! April 1 Report � May 1 Report Equivalent � I of New Snow Over . Water j Snow 'Maier I Srow Water ' Snow Water Spar Gulch Snow I D Date Depth , Equivalent' ate Oeptn Equivalent Date Depth Equivalent Date Depth Equivalent 9asin (Inches) (Inches) i 1 .'Inches) (Inches) ( (Inches) (Inches) ;Inches) (Inches) (Inches) i 1957 2-01 63 17.9 3-01 89 21.8 4-01 78 28.4 0.44 1958 2-28 56 '13.3 3.31 e4 16.3 0.44 1959 2-01 31 6.1 2-25 46 10.5 3-28 45 13.5 0.44 { 1960 1-25 28 7.5 2-25 41 10.2 3-25 53 15.6 4-26 35 10.8 0.44 1981 1-27 32 8.1 2-23 5C 10.6 3-27 57 16.e 4-27 62 19.1 0.44 1982 1-27 88 15.8 2.23 82 21.0 3-28 81 30.3 4-23 83 2e.3 0.44 1983 1-25 21 19 2-23 34 6.4 2-30 40 10.8 4-24 38 12.2 0.44 7 964 1-25 33 7.3 2-22 39 8.6 3-22 57 16.3 4-27 50 18.2 0.44 1985 1-28 53 16,9 2.26 58 19.9 3-29 103 29.9 4-27 80 28.0 0.44 1988 1-28 34 9.2 2-25 4C 112 3-23 43 12.9 4-27 38 11.4 0.44 1967 1-29 43 10.9 2-27 59 18.0 3-29 50 19.3 4-28 53 18.2 0.44 1968 1-29 34 a,s M6 46 12A 3/29 47 14.3 4/28 58 22.3 0.44I 1969 . -228 58 12.7 2/28 49 17.0 3/29 54 18.1 4/27 43 16.4 0.44 1970 1-28 43 12.9 2125 53 15.2 3/29 83 17.5 4128 70 24.9 0.44 197: 1128 42 12.0 2126 56 15.3 3129 65 20.7 4128 81 21.2 0.44 { 1972 1 /28 42 V .) 2/26 50 13.9 3/28 49 14.4 4/28 50 17.7 0.44 � 1973 1126 38 10.2 2/26 42 10,8 3127 55 17,0 4/28 82 22.2 0.44 1974 1128 44 12.8 2/25 47 13.7 3/29 48 16.0 4/e8 45 17.0 0.44 1975 1128 40 10.1 2/25 46 13.3 3/28 61 28.3 4/28 80 20.2 0.44 1978 1128 34 10.3 2125 43 14,5 3/28 52 '7,0 4/27 46 19.3 0." 1977 1/27 23 3.5 =5 30 5.0 3/29 39 10.2 4/23 30 9.7 0.44 1978 1/28 52 15.1 2125 50 15.9 3/28 59 20.4 NS 0.44 1979 1125 42 12.3 2/24 48 13.6 3128 74 21,7 4/27 56 22.2 0.44 1980 1127 43 11.3 2126 58 17.8 3128 69 23.0 4128 58 23.8 0.44 11 1981 1126 24 5.4 2123 29 6.6 3/26 46 12.4 425 38 14.8 0.44 .982 1128 54 21.8 2/24 58 19.0 3/2e 68 23.6 4/26 64 26.2 0.44 1'983 1/24 33 8.8 2/23 48 12.3 3/25 71 20.4 4/25 65 23.0 0.44 1984 1125 55 19.6 2124 66 Z3.2 3/24 82 29.8 4126 87 33.0 0.44 1985 1125 48 15.4 2/23 62 / 8.8 3/23 86 21.6 4/24 67 22.8 0,44 Average 41.3 11.3 50.4 142 80.0 19.1 56.3 20.0 Maximum 88.0 21.8 82.0 23.2 103.0 30.3 87.0 33.0 Minimum 21.0 2.9 29.0 5.0 3910 10.2 30.0 9.7 Avg '63-'77 39 10.1 48 13.0 55 17.4 53 18.6 Avg '57-'77 40 10.3 49 13.5 57 18.1 54 8.8 (a) SCS Gage "Lift" - Colorado River Basin (Roaring Fork) Gage No 08127 Let 39 Deg 11 Min, Long 108 Deg 51 Min. Looted or Aspen Mountain at east of Sundeok, Sec 7, T11S, R841N, elevation 11,250 feet. Leonard Rice Consulting Water Engineers, Inc. (Printed 31-Jul-97) File: Snow_RO.W81 AUG 01 "37 12:00PM L R 1 Aspen Skiing Company Preliminary Table 6 Water Equivalent of New Snow Spread Over the Major Tributary Basins July 30, 1997 Area cf Water Water Total New Snow Equivalent Equivalent Description of Basin Tributary Included in New Snow Over Conclusion Area I This Basin In This Basin Whole Basin (Acres) (Acres) (a) I (AcFt) (Inches) Spar, Copper and Vallejo Gulches 657 42A 24.03 0.44 Not Significant Keno Gulcn, inc;uding import from Scar Gulch via Summer Ditch 502 40.4 22.89 0.55 Not Significant 31.73 Water Equivalent of 56 Acres of New Snow Area After 6% Spray Loss. (a) In the case of the Spar-Copper-Valleic Gulch analysis, the Summer Ditch is not considered. so 42.4 acres of new snow area contribute to the whole Spar Gulch basin, as does the entire area tributary to the Summer Ditch, Leonard Rice Consulting Water Engineers, Inc. ( Printed 31-Jul-97 ) File; Snow_RO.WB1 aIJG 01 -?7 : Q©Ph1 W Aspen Skiing Company Preliminary Table 7 Average Rates of Flow for Melting of "New" Snow Water Eauivalent I Flow in CFS for Number of Days of Snowm of New Snow (a) s o 'S August 1, 1997 Keno Gulch Analysis 40.4 Acres Reported Average Year 7.46 22.89 11.54 5.77 3.85 1.85 0.82 0.38 Computed Average Year 7.52 23.07 11.63 5.81 3.88 1.66 0,83 0.39 Computed Maximum Year 11.27 34.60 17.44 8.72 5,81 2.49 1.25 0.58 Computed Minimum Year 3.88 11.90 6.00 3.00 2.00 0.86 0.43 0.20 Spar Gulch Analysis (b) 42.4 Acres Reported Average Year 7.83 24.03 12.11 6.06 4.04 1.73 0.87 0.40 Computed Average Year 7.89 24.21 12.20 8.10 4.07 1.74 0.87 0.41 Computed Maximum Year 11.83 38.31 18.31 9.15 6.10 2.82 1.31 0.51 Computed Minimum Year 4.07 12.49 5.29 3.15 2.10 0.90 0.45 0,21 (a) After 6% spray loss. (b) In the case of the Spar -Capper -Vallejo Gulch analysis, the Summer Ditch is not considered, so 42.4 acres of new snow area contribute to the whole Spar Gulch basin, as does the entire area tributary to the Summer Ditch 0.28 0.26 0,39 0.13 0.27 0.27 0.41 0.14 Leonard Rice Consulting Water Engineers, Inc. ( Printed 01-Aug-97 ) File: Snow ROMB1 /: funnel. muggle• ` o i ; . Shaft t" ( (( \ 10. ��- - �/.,, :� ••� \ Tppralel°Moilia Gi I' o• • `1. \ : \r.ae ..� 1. N \ C ••N�q,N ,I C ` �•• .. �.•: ,1 .. • P`••- Par -a^ y 1. r • � :; �. .> ,�� • *s ; . _ �,�' , • ___.�'�\;?.r�lil � • lop, CPO �` ` ��1 i � �1 i• �er��r�"�,�Stt.::,'.\ �; ;(f�_�� �N1� - _ -�`; .�� -`. �- • '� Water; Iank—. N' I �, ie �� _ V!•' l.. ••e. .I�•I: r `�'�C'�^( ,1 \ �� �s-'� ,, `�� ��. .., Tvii •,5� �� r :��.�\� o.. �\ 1� I . � :III � ', ``� _ � `Y 11 • � � • � � , \ � \ �� r I .. (� v •• V��..:. �-4 �;. Gra�ei Pits - 411 -Z p� a ��\ \ \ ��' r� \\\ `� \ • p Ap `' vo- \ 1 � M nLa = �\ \ � • oiz s2 \ �T site xll - �/ '—%.^-\`�.0 \`\\ \\` Do;� �` ��.\`\� m\� ,�{�`I',1 \ �\�\ '� _•�_ �\ ���` 1, �\\ \`\, �\\{ I Jr' '%i ��\ ' i�,✓//�_' i ll�"����I��i� ,n� \ .\\�� �\ \ �+ \\ .'I,\ > 10.312 \ '1 I' `.dl I oi' !� 1 ..`` Iq•�'\ 1 r'i`! ,a, �Cir� ` \�. I11,' \ I a,-} \ \ �` . 1 o1V r ' \ \ \ // _ r�l: li (/. /�� \ V it � `�iN I I .' : a• 1 N ;\ � •' /_� \�� }•. . � -y In �/��\� � i ` �\•',�� �i� ' ,, 'e , , .� �I ,•.�� _\��\ `l . i1 _ _ l� `\ \:, � ��lI) , \�'� �`,� � ��'� ��„�,• � .N ;"i 1 �'� • it � '� � �\ � ;- s. % '//�� \\„ \\;:� 11' �i i11� tr'h•..'ii..};�—� \ �.�.:1. � 13 \ \ '�;, �� ,r.� «i —`"� �. L 1 AUG 01 '97 12:01PM L R W E ti t� i�7 N O saaoy ui e9jV Aaelnq±jl I : t;UG 01 '97 12:02PM L R ' c i 8 F 23 �c a i 0 ^^++ W � cri � a� 0 E s AUG 01 '97 12:03PM L R P. 20 LE C. 0 LM ct '� 4 CL 1RC: E E z c did L) 0 > cl, 6: 4) 1 a CLCL 0 c C) 0 G C 0 Ln N Irl sajoV ui e9jV Aje;nqpi TL 0 V IL AUG 01 '97 12:09PM L R C W E P.2 , I I 1 3 T I i I I � I i I I I 1 I I 1 I I i 1 1 I I � I I ILL I M 1 �— I I I I I I i � I , 1 1 � a N N tl) O S94OUl `MOOS;o Ju81Bninb3 jejeM H, AUG 01 ' 97 12 : 03PM L R E at M V a o W o u) o �- c� col N N r- V" sayoul `MOOS 10 Jua1Bninb3 JOIBM P.3 AUG 01 ' 97 1 OPM L R ' ' E P.4 O LO I I T q Ln Ct) �ii i I I It� o c U.)z N 4- 0 rl E cp - I � I N In O O Sjo '.4ounN Jj9W noug 8115MAb I� CL 0 �U Irl P.5 10 15 I I o� I 1 I I ! I e CD I 1 I I I 1 I 1 I i IA I 1 I I I `Vi I I I 1 I 1 •� � Q I I I { I II I I 1 I v♦ I 1 w o cn Cr I 1 I I I �'/ cin Ln I I I ! I 1 I ' 1 1 I 1 1 I 1 1 ' I Z N 4-- 5 1 81 CY I I I 0 L� f � 3 I � I I/, I I � �• CL I I 1 I 1 I I I Ki jI I 1 I I w Trr-1- � 0 CD tn O Li a M M N N r T- 5_�C) `.4oun,�j 119LU OUS 9beaend r a -5 PUG 01 ":- 12: 11PM L R C W E r I LD C. f � S I I� i I � I I I � I= C i LL 1 Q I OD tp et N O S9gOUi Ul JU9jeninb3 aaleM AUG 01 ':7 12:12PM L R C W i= P.7 W M i v C j o Jig I d 1 ` � j , 1 o i �� I N C O �2 I I I I 1 I I I I I l N O C�? M N G O O Q O O O O O O CL Q d W ti AUG:31 "37- 12:13PMLRCWE P.3 Rp l .r I O O C � i I I 1 i j l AUG 01 '97 12:1'-:'PM L R C W E P.9 BACKUP DATA Leonard Rice Consulting Water Engineers, Inc. Aspen Skiing Company P.10 Preliminary August 1, 1997 File: Snow RO,VIIB1 30-Jul-97 Last Update This Notebook Created by Leslie H. Botham, of Leonard Rice Consulting Water Engineers, Inc. 303: 455 - 9589 Purpose: Quantify Impact of New Snowmaking on Aspen Mt. ASSUMPTIONS FOR THIS QUATTRO 5.0 FOR WINDOWS NOTEBOOK: Flowrates and Volumes: 1.9835 Acre Feet per CFS Day 449 Gallons per Minute per CFS 7.48 Gallons per Cubic Foot 325,850 Gallons per Acre Foot 0.646272 Million Gallons per Day (MGD) oer CFS Time 1,440 Minutes per Day 85,400 Seconds per Day Lengths and Areas: e40 Acres per Square We 5,280 Feet per Mile 43,560 Square Feet per Acre Misceianeous: 3.21 Feet of `.Hater per Found / Scare Incn (PSI) 82.4 Pounds oer Cuoic Foot of Water Q 30 Deg F 32.2 Gravitational Acceleration Constant 2 Rounding Constant Specific to this workbook: 01-Nov First day for restaurant's water use 31-1j'an Last day for restaurant`s water use 30,000 Gallons used for restaurant use every 0 days. 180 Acres of axisting 9nowrnaking area 5a Acres cf r.ew snowmaking area 0 Days per 0-gallon water -use block of time for restaurant. 11 Milliori gailcns per year for new snowmaking area 8% Spray Loss Leonard Rice Consulting Water Engineers, Inc. ( Printed 01-Aug-97 ) File: Snow_RO.WB1 CITY OF ASPEN ASPEN , COLORADO URBAN RUNOFF MANAGEMENT PLAN K.2��r2rtC� vepy J%=Wnry r -rW%aw ING1NMING iEPrT, Oi T Y OF ASPEN, SOX V ASPEN WRIGHT.Mr-l.AUGHLIN ENGINEERS ENGINEERING CONSULTANTS OENVER. COLORAOO AUGUST, 1973 AUG 01 '97 12:16PM L R C W E P.12 ASPEN MOUNTAIN LODGE, 700 SOUTH GALEMA STREET, TOP OF 14ILL AND UTE CITY PLACE STORM WATER DRAINAGE REPORT PREPARED QY REA, CASSENS AND ASSOCIATES, INC. C014SULTI`iG ENGINEERS 4388 SOUTH WINDER14ERE STREET ENGLEWOOD, COLORADO 80110 789-4428 1-800-332-9596 201 N, MILL ST. SUITE 207ASP��1'�ECflLUftADOI 8�1611BUILDING 925-2799 January, 1985 m.:,t,9li'rlSTi'*Ct7:°..ST`�-`;^ e ti _ ,. •+. L _ 7 7' rti Yt ♦ 47 F `; '� r i;,` \ . »: 'y it b GY� FR �� ` ..o��i��, #zY. ;: �1f$..+t.'l r_ � �.`�ryrrr�. �- :'��.��t1-. '._i. eta - •- .. - t "F - * r -.n ' 's.[ .so-rr 7���. L � , rr r '' r%(s'�� �•wr PL t:: +' . ,. - 9 P } �`` •tv. �.,.. � � } ��� -`�"' J�4 �.yy������♦ree•4� - � T ..,� �--'���CCs r iy��•il r. ` �%u� �4r"•� .v t.+. �. ! rr• •F�'w� �. t+ :-r 1 e J . � t♦,i > F � ,.r _. "� t'�'•t� f a r r � -� t� r}. -. �': � � • .. _ r '�` �•� . ' 49r, r�yY' 3'. fi."M rJ> y�i. ,�- - 4x' i'i�i sr r. r i^� `S + �� y' -,ta, a . �' t l;. air•( _ . 74 .i +..' .,e•� i+ s'i•*.1+ s t -v<, .r. -f'r ntl t yy r v i ie tp :irr'- :Y� a . N ' r�:yr. r � .ram Gt � • ,{„ rt s t . +t�� ^L: '�f J.,,_ ± ;.. s�i.� b �' r � "� � . . as <�', 'Q7, ?�"' s i3• L¢� +�°, r� � y. r '1, v ?�r�-Sf-� '. - '�' sue. y ,;• r.r r"FTr-+ 1`°"F� "'i..� .T�,A"�,� Iw• '�. y, �i''ig t T. u 1y R`i - 1 ,T °�'� r � « T ".% r 'r"1� r - -� - • • � c � S - �. ~'�-tYR�.�`% L��il�.r:�r�.�.��1'��R'.ir�� - -- - ... _. s'��eS��- r�.���` ��' �...w�.t ,4 Ca^� . � • �`1� r ",•`� .� Al , ��y1�'�y�vr I ! • -r r - • >,+ �S1•.+ N-�..lL �a���f j..i� - �r '�,.R .A:% Rt r� �` 9 C"! ' tir try ✓. t�f-='?`f„• e t 4 a ,� r 1 f.: - t _, ''Ate..�"a",.t�:������..w•atr.�'.:.��.✓'�•.a.-Rn '�., ke....._. i:1 i�-• reaiP`�eh:{'. s.lv=+._•� ddd��h : ax.. �..• RW"1 9F AUG 01 '97 12:21PM L R 1: W E R.14 rl 1;4o•I It.h , tiLht tl+!t t+' ;' KI a� d "54N• • Aspen R'r.-+-• ', ��° j "n f•1�'•..' '.N�•�•.y'••..I.'r•+ 19t77111 �� `r1 I 1 �♦ �1C `• ��;",� ••' �� • ... WM 04", =j — �r1 + Lutj lyn��l,: Tu IshAR ,� l\` 1 r. • •e+::1 _. .+.: ' `, 7w1Jaf►Mai 1• C;. ;, •, // y • ,' r.y.rr..`. ••4 "" Parts •T •A . .' � •• f �.r 1 4 'II rC I f1 �•\^�1' ,1��� 4�e p.�.y '�..y •..:.ul'4,r r.: 1�" +�� �: 13hi It • '� . �� ....j �• tit \\ . F.,� , �F �..z:...:,.•.., .1 ' .•+ � ;.�,.: Tank !' ! t !y�+ t • N �', ,t� 1~r• i' Iww �• '' `' `!�. ` u Kf , . . ,r T�nit-. fir. I �. �.'•' ' ' p IrA�►7g BOUNDARY .._ _gym �```,�_: , �:;ti• Y1� BEN NIUS(C pF MUDj. FLGW,S � �!,` ;, ; � . �, ,.`,•y' . jtoC 4 I 7 r •��� 1 r BAR GULL APPROXIMATE BCPO DARY ! �OF LANDSLIDE AREA - DITCH DIVERSION 1 a,r Mountain ! W H r T - TaulKelloets� I`� ' 4� WRIGHT WATER ENGINEERS, INC. _490 W. 25TH AVE. DENVER• CO 80211 (303)480••' 1700 DRAWN OSS t OOA CHECK JWR DATE 196 3CALit V _� 2000' FIGURE 1 INDEX MAP ASPEN MUSIC SCHOOL DEBRIS FLOW 961.062.000 S CUT SLOPE I ROAD ON STABLE BI 15' SCARP STABLE IN MORNING WET AND RAVELLING IN AFTERNOON- ORIG. STABLE GROUND HEAD SCARP WITH LOOSE CNAT NNELTREND OE NT5• W COVER, CLEARED OUT ARESSE TIMBER pE ;HANNEL Ct1ANNEl CLEAN EAM RUNNWG THI M OVER _ STR r BEDROCK HEAD SCARP r 'a WIDE 39' SLOPE ;'DEEP TREE DEBRIS 10 G 46' ORIGIN OLD ROAC SLOPE TO � O G NOTES: WHERE AS FIELD ESTIMATES WERE HORIZONTAL MEASUREMENTS, THE EAST-V SKETCH MAY BE DISTORTED AND MAY BE 2 OVERALL TREND OF CHANNEL HEAD/SCARI OVERALL SLOPE OF CHANNEL HEADMCARFDLD MADE MAY 17, 3 AND 14. 1996 AFTER THE DEBRIS FLOW WRIGHT WATER E FIGURE 3 2490 W. 26TH AVEE SOURCE OF KENO GULCH DEBRIS FLOW DENVER, CO 8021 (303)480-1700 PEN MUSIC SCHOOL DEBRIS FLOW 961-062.000 and Alan Chleborad, landslide experts with the USGS; and others. There seems to be some differences in the various opinions as to the imminence of the slide and the degree of danger ?' from it. Suffice it to say that the AMS personnel took the warning seriously and went on the 1 alert. Bill Savage and Alan Chleborad (personal communication May 29, 1996) estimated the volume of the landslide as 70,000 cubic meters, Field evidence indicates only ore -third to one-half of the material had released as of May 17, 1996, Mr. Blanning (personal communication May 26, 1996) set some monitoring stations on the head scarp of the slide and said he noted movements of two feet, four feet, and eight feet on successive days (apparently Friday, Saturday, and Sunday) leading up to the Monday event. On May 14, Tuesday, after the Monday event but before the Tuesday afternoon event, many of the people revisited the site, and Art Mears and Jeff Hynes inspected the slide and the channel down to the AMS campus. On May 17, Robin VerSchneider and John Rold visited the slide and spent most of the day mapping, photographing and evaluating it (Figure 3), The landslide represents a typical example L of an alpine landslide which became a debris flow. The rapid snow melt infiltrated the landslide initiating slow movement, cracldng, and bulging for several days. The cracks and dilation allowed additional water to further saturate the slide to the point where it mobilized as a very fluid debris flo w. On the 30° slope, it quickly would have attained a high velocity with considerable erosive power. When it reached the confluence with the Spar Gulch drainage diversion, the additional water provided greater fluidity. Art Mears and Jeff Hynes, who visited the site Tuesday afternoon between the two events, each separately related to WWE their hypothesis of the conversion of the landslide to a debris flow. Wright Water Enginsers/John W. Rold page /1 10 W, AUG 31 ' 9 7 !':22PM L P J =).1 A Each elf that the landslide had slowly oozed downhill to the ;unction of the Spar Gulch drainage channel where it plugged or dammed the channel. T-he additional water then mobilized the landslide, turning it into the debris flow. They actually felt this might be beneficial overall All bec ause the channel water would mobilize small portions of the slide, a little at a time, as it 1 moved down. This would release the material in small, separate surges, thereby avoiding a t larger, more catastrophic event. Based on a detailed site inspection, WWE believes the field evidence Figure 31 belies this interpretation and indicates that the landslide became a debris `flow in essentially its origina! location and was a debris flow before it reached the Spar Gul h diversion channel. ii 1. Ss icier^t water would have been available from the rapid snowrnelt to mobilize the landslide. Considerable snow wcuid also :nave been incorFc:3ted into the landslide and { debris flow, i I The narrow chancel between me landslide site and the ;unction wouid more Aely have been ` caused by the erosion from a debris flow than movement of a landslide Maass. Mud spatters found on trees above the char7ei indicate a high ve!ccity. 3. Materials left �n the channel indicate they were rcn nanta of a debris flow, not a landslide mass. 4. Messrs. Mears and Hynes and others visited the site arc nd *noon Tuesday. The slide mass was then 200 feet to 400 feet above the cenfl.uence with Spar Gulch. In the three to four hours until the : ext event, the material would have to have moved at a rate of 50 feet to 100 feet an hour to Teach the junction, form a darn, and mobilize. At anywhere near that velocity, m the material would have mobilized.. ?i `, Wright Water EngineerTdOhn W. Rold page 12 AUG 31 '91 _` 23FM L F J = F.18 i I anew {A..ein GAnnl nehrle F10 I.A Wfl thick. Only a very few boulders larger than 18 inches across were noted either in the debris flow deposit or the landslide material. CONCLUSIONS 1. The landslide and the debris flow were dominantly a natural event caused by rapid melt of an unusually high spring 1996 snowpack (139 percent of the 20-year average), Z. Field evidence indicates that the landslide had mobiLized into a debris flow before it reached the confluence with the Spar Gulch diversion channel, Therefore, -although the Spar Gulch diversion water may have increased the quidiry of the material, it was not the cause of the landslide or debris flow. j� 3. The occurrence, magnitude, and behavior of the two debris flow events differ little from predictions Art Mears made in 1989 and i 993. I _ 4. Under the adverse conditions that existed, staff of the AMS made a reasonable emergency response to the event. 5. The old mine access road above the landslide head scarp may have exacerbated the problem by concentrating drainage into the landslide area. Material removed from the road cut above the slide may have been dumped over the side and may have exacerbated the landslide process. 6. Approximately one-half to two-thirds of the landslide mass remaiTs uphill in Keno Gulch. Another spring of rapid melt of a larger -than -average snowpack or an intense or prolonged thunderstorm event could trigger additional debris flows similar to, or even somewhat larger Wright Water Engineers/John W !told Page 14 7 HUG 01 '97 lc:=aPM i_ Aspen Skiing Company F.1s July 31, 1997 Assumptions used in the Colorado Ski Country USA 4Y Procedure for estimating runoff due to ski trail clearing and making Study Period Average Tota► Water Used for Snowmaking = 11,000,000 gal Ski Slope = North Aspect Initial Loss is assumed to be 8% due to lack of temperature data during snowmaking Number of acres of snowmaking = 56 Based on Criteria Table - Aspen is similar to Silver Creek in time distribution Winter = October 1 - February 28 Spring = March 1 - June 30 Summer and Fail = July 1 - September 30 Leonard Rice Consulting Water Engineers, Inc. ( Printed 31-Jul-97 ) File: Aspen.WB1 �i W i r z z J' W u W U..- 2 yea z co O0cn a� L W uW a� cc CD V Nth W WLM • Z Q � J riL'!dp � N a c w �j tL CV0�1lN U)04 �tnN y a �, g c;anui aiai0 � � a 99 d ui �o V I a� o to _ Y IM E. G o c � P.20 z W a. Ai U. V z N z z w x W a 3 c� z F cn z 0 w U G O w J - LG 01- ' 97 12: 3)ZPM _ z? .,� _ r g 7 .9 LL �o m U. LL ljrr r v a w Z t� � Q W � OI� � U N ti 0 s1 C a a W y OK t 0 c n I U l— !� H+ W. CP r In ��o �n 0 i0 a Z ui� i 4 a W U Ix 0 ". ! O a 1 Lei a as > W Z CL 4 LL N N ~' '° a w 0I 0 H Gf u ) C AQ 3•(µ m w a AN LL U z N w w z 3 z w cr H J z 8 Cw) m a O w 4UG 71 '97 1Z:32FN _ F 2 S2 Hti O 0O O O O O N�; s 00000 •1 OOOOOc7tD�?Q c�SuQggav��a 0000co�oo 0 0 0 0 0 0 7 N Q I U. U. a� �' ��00000ao OU. T LL W s lu r' A �I 4 a �YQ gU.w ruw..0 y Y20wa! oa�oocooa NCNN NNNNNN IL � J O F� 0zag,uw. K n • ',f THE COLORADO SKI COUNTRY USA WATER MANAG E,�vAENT RESEARCH PROJECT • � HANDBOOK ter' tlk FEBRUARY 1986 UG Q11 '137 1 ------DM L R W _ FIGURE 2 MEN RELATIONSHIP BETWEEN PRECIPITATION AND EVAPOTRANSPIRATION DURING THE WINTER SEASON AT COLORADO SKI AREAS (Reproduced from Figure 111-24, "An Approach to Water Resources Evaluation of Non -Point Sllvi'cultural Sources" Troendle and Leaf, 1980) 0 Z 4 q a IW SEASONAL PRECIPITATION, !NCH£S RELATIONSHIP BETWEEN DURING THE SPRING !I' 5 4 3 2 P FIGURE 3 6 PRECIPITATION AND EVAPOTRANSPIRATION SEASON AT COLORADO SKI AREAS (Reproduced from Figure II;-25, "An Approach Resources Evaluaf7roendle andion of PLeaf oint Sjggp�t"ral 0 2 4 F9 aiv SEASONAL PRECIPITATION, INCHES to water Sources` r PUG 01 '97 1 :34PM L Rt -35- FIGURE 4 RELATIONSHIP BETWEEN PRECIPITATION AT COLORADO SKIIAREAS DURING THE SUMMER AND FALL SEASON (Reproduced from Figure 1 1 1-26, 0An Approacn to Water Resources Evaluation ofn-,Point S1980�urot Sources�� Troendle and 6 0 Z 4 0 0 - SEASONAL PRECIPITATION, INCHES PUG 01 7 1!:34PM 37 P.7 FIGURE 5 RELATIONSHIP BETWEEN FOREST COVER DENSITY (Cm) AND EVAPOTRANSPIRATION MODIFIER COEFFICIENT ( ) 1.4 1.3 0 �dTaxld FOREST COVER DENSITY (Cd) NOTE' FOR BETWEENATE HE NORTH —SOUTH LINES. lax ;�UG 01 12'35PMLR CW= +39r /Wf FIGURE 6 RELATIONSHIP BETWEEN INCREASED EVAPOTRANSPIRATION AND OUANTITY OF MAN -MACE SNOW FOR AVERAGE, WET AND DRY YEARS 6 YR. YR. C O 5 io 1 � r.v �.. WATER FEQUIVALENT OF MAN—MADE SNOW('tn.) PUG 01 '97 12:35PM L R r W E a.'3 -43- Table 1 CRITERIA TABLE Guide to reference tables for use in distributing the change of runoff and evapotranspiration due to snowmaking over the time period October 1 to June 30 I� Average Annual Use Reference Table Precipitation ( inches) Location for � 35 West and Snowmass -(Table -5) East Slopes 30-35 East Slope Lake Eldora -{Table-3) 30-35 West Slope Winter Park-(Table-7) or Vail -(Table- 5 ) (Use the one closest to your area) 430 East Slope Conquistador - {"able- 2 ) AUG 01 '91.2 * 3t�PM L R P. i0 a 0 m w W 0 C �+ • �e^+ O p O O e d sn ^• e w IC ��— W A �F' �> s:� O O p p o o� e� d• W r'+ V3 i+�•.r zy r _ r, •• L S O p O O d O d � e7 O '•" ��G 4 a m , m� c d o ac 3 .» g �. 0 0 e e o c a o a rim z I� •c •.- W im •+ i�� •^ o 0 0 o a a N� a SIC �+�= .�' N f. Summary of Snow Surrey Measurements Colorado and New Mexico 1971 — 1977 ,'✓��"!' y r- w9te r '/ .�>tF rri„ TS �� `F �', : 31•?� t ; � •, s r: T li �g..�..��. .���� � ram} � , r.l ,�• r��±��,y ��''ilr�. T -� 'i'. ` y1� �•Y � .r ' fir.. .. � Z� < .w� ��! ' *.. —'F •�i � u' - .. r ,` -^�. �u �'- + �1 f ��^v•�. _ Lit r 'rviN 1;4..• •L"e 1`+;ni . •.may '� ;`.40 i �. . .4•Gs 7 a N n,/^�,.,: ' �r -!M^'"n'p:'�•�:r y'�y,• �' 4. = •7 •� �� .r � ��� •�i"`r y. ....�� r�•�'� P �— �+, � �'l ._�14 .�„ may' - •'ti l .' ,.� � ,=� .`� ����1 Federal -- State ---- Private Cooperative Snow Surveys U.S. Cepariment of Agriculture Soil Conservation Service A +—•iT+Y-.P � AW 01 ' 97 12: 37PM L R ' ' E fti P.12 AUG 01 '�'7 4L2:38PM L R r W E Aspen Skiing Company P. 13 July 30, 1997 I Tadle A Capacity of Summer Ditch As Limited by Its 18" CMP Headwater I to Diameter I Depth at Estimated Ratio Inlet Discharge HW/D (Feet) (CFS) 0.5 0.75 1.8 O.e 0.90 2.5 0.7 1.05 3.3 0.8 1.20 4.1 1.0 1.50 5.9 1.5 2.25 9.0 2.0 3.00 11,2 Assumptions; inlet Control Projecting Inlet 18 Inches, Size of CMF Culvert to Summer Ditch 7 17 121 7 17 121 7 17 121 7 17 121 I 7 17 121 7 17 121 7 17 121 Leonard Rice Consulting Water Engineers, Inc. ( Printed 31-Jul-97 ) File: Snow_RO.WB1 '4jj '..01 ' 97 1c 38PM L R W s _ l �ku`T,�'(r : R 'it:'" *"re; i+�r+' : +P . 144Alw :�� CHART 5 Irao 10,000 8� � � f66 ,000 EXAMPLE 156 6,000 0.16 inches 13.0 tut) 5,000 0.66 etc (3) 144 4,000 N e NW 5, 6, 132 3,000 flat► gr 6, } 6 (1) r.tl S.♦ 1 )205. � 2,000 f11 2.1 t:.3 s (3) 2.2 106 3, 4. d 'Q ill tut 96 1,000 3. 600 3• 84 a 600 P. �— I 500 j 400 _. _ _2... _ . 2. f (A7z ? 300 W rz 60 ti 200 �p��/ ; U) f.S 1 I r 54 J t 1 is 10 0 46 4 go/ G _ zf u 60 4z / T) 50 / r C 4C �` C 1.0 69 0: 30 .• w '� '/ ENTRANCE, �6 p,�3CAE TYPE r r 4 33 6 ;p i' (!1 Mitired to oontorm yaj 6 to flue ; 27 r' 10/ s 24 : r — ._. r _ ._ .7 To use +eelo (;),er (3)`�reject 21� `4 then 6 e>re *freight inelinel Iiee through '6 i •. �, .� 3 () en3 0 +sate+, or rereree oe .5 1.0 .5 ! 12 HEADWATER DEPTH FOR C. M. PIPE CULVERTS WITH INLET CONTROL BUREAU or PUBLIC ROAD$ JAK 1963 1 1 9 9 7 Aspen Mountain Master Plan A ugust 1, 199 7 Topo of Sundeck Area(Attached) Photo of Aspen Mountain circa 1958 courtesy of Apen Historical Society 1 9 9 7 Aspen Mountain blaster Plan August 1, 1997 Sundeck Facility and Operations Photo of Aspen Mountain circa 1958 courtesy of Apen Historical Society Memo To: Brent Gardner -Smith, Planner for Community Affairs From: Bill Kane, Vice President, Planning and Development Date: 08/01 /97 Re: Sundeck Facility Building Program and Operational Description, Additional Infomation Attached please find a revised Aspen Mountain Summit Program generated by Cottle, Graybeal and Yaw. The program has changed since the Aspen Mountain Master Plan was originally submitted, primarily to avoid slopes over 30%. Additional architectural detail will be submitted to the County upon request to aide in the master plan review, however, as Cindy Houben notes in her July 11, 1997 letter, "the Sundeck proposal, to apply for Commercial GMQS, is acceptable." It will be appropriate during the GMQS process to present final architectural detail and to determine at that time, appropriate employee generation mitigation. I do understand, however, that as part of the additional information package submitted to the County on August 1, 1997, there is additional employee generation information based upon the current Sundeck program. In regard to the County's request for more information about night use of the Sundeck and the Silver Queen Gondola, I have had extensive discussions with Eric Calderon, General Manager of the Little Nell, who is responsible for operations at the new Sundeck facility, and have subsequently developed the following information. The program includes a cafeteria or scramble operation that it is the same size as the current facility (225 seats) and will employ the same number of employees. The physical area will be re -designed so it is more efficient from several perspectives, including food preparation, serving and cashiering. In addition to a replacement of the existing cafeteria service, there will be two new dining facilities at the Sundeck. The first is a sit down dining room with 100 seats that is open to the public for both lunch and dinner. The restaurant will be named `Benedict's" in honor of Fritz, Fabi and the Benedict family. 0 Page 1 The second facility is a sit down dining room with 100 seats that is currently being called the "Hayden Room." The Hayden Room will be used as a private lunch room during the day and as a public banquet room during the evening. The Hayden Room will be available for use at lunch only by members of a new club concept that is being planned. The new club will offer its members benefits at a variety of Aspen Skiing Company facilities, such as ski concierge service at The Little Nell and signing privileges at the Snowmass Lodge and Club. Lunch at the Hayden Room is only one aspect of the club concept. Both Benedict's and the Hayden Room will serve lunch in the winter. In the summer, only the Hayden room will serve lunch. Benedict's will be closed. (The summer lunch business is not strong enough to support two sit-down facilities.) Both Benedict's and the Hayden Room will be open for up blic banquet service at night in the winter and in the summer. The Hayden Room, then, is essentially a private lunch facility only and is part of the larger public Sundeck facility in the evening. We are proposing that the gondola and the overall Sundeck facility be allowed to operate for up to 100 nights in the winter season and 100 nights in the summer season. The winter season on Aspen Mountain is now typically 150 days long and the summer season is typically 100 days long. The reason the number of potential nights of operation is the same for both seasons — despite the varying number of days in each — is because summer is a stronger season for group business. The gondola will be operating solely to transport dining patrons in organized groups to the Sundeck facility — the only planned activity at the summit. There are no meetings or conference services planned. There are no other night time activities planned for the summit than banquet -style dining. Dining at the Sundeck will be primarily for organized group banquet -style dining. The average size of a group that books one of the three rooms available for group functions - the Sundeck, Benedict and Hayden rooms - is expected to be between 75 and 100 people. However, there may one large banquet group on any given night — up to 400 people — but no more than that. While there are 425 seats in the total planned facility, the kitchen facility will be designed to handle no more than 400 dinners at one time. If a group of 400 does book the facility, they will be accommodated between the three different rooms. It should be noted, that while architectural work is still ongoing, it is likely that the Sundeck Restaurant and Benedict's will be adjoining rooms separated be a removable wall. If this is the case, it would provide the opportunity to handle group banquets of between 225 and 325 people in one room. On any given night, there may also be three smaller groups that book the different rooms available for banquets — the Sundeck Restaurant, Benedict's and the Hayden Room. This is a 0 Page 2 far more likely scenario than one large group booking the facility given our experience to date with banquet business at the Sundeck. It is not anticipated, however, that either during the 100 night summer season or the 100 night winter season window of operations, that all three function rooms would be booked on any given night. Indeed, the current business plan for the group banquet facility on top of Aspen Mountain calls for the Sundeck Restaurant to be in use for 45 nights during the summer and 30 nights during the winter, for Benedict's to be in use for 25 nights during the summer and 30 nights during the winter, and for the Hayden Room to be in use for 30 nights in summer and 40 nights in winter. The 100 night "window" for planned operations in both winter and summer is just that. Actual use may be less than a total of 200 nights but will not exceed that. It is important to provide a large window in order to provide flexibility in scheduling of banquet business and to provide flexibility for weather -related shutdowns. It will be the sole discretion of the ski patrol team on duty to make a "go/no-go" call each by 5:00 p.m. as to whether or not their will be night operations based on weather and operating conditions. We anticipate that within the 100 day operating window in the winter, there may be as many as 20 nights, or more, when the patrol makes a "no-go" call. The patrol will have complete authority to make this decision based on storms in progress or forecast. There may be evenings, especially on Saturdays (travel day) in the winter, when there is no group business available for evening banquets. It is anticipated, then, that on about 20% of available evenings, it would be advantageous to be able to offer to the local community the opportunity to experience evening dining on top of Aspen Mountain. The function of the banquet -style operation would not change. Patrons would make reservations, would travel up the gondola in the same manner as a previously organized group, and would be served from a fixed menu at the same time, just as if they were a formal group. The advantages to banquet -style public dining at the Sundeck facility over an a al carte type of normal restaurant operation is that is provides for a fixed arrival and departure time on the gondola, eliminates the need for the gondola to be running during the entire evening period of operations, provides for a cleaner decision to be made regarding cancellation of dinner due to inclement weather, and allows for more efficient dinner service during the necessary fixed - time for dinner unique to this type of operation. It is proposed then that there will be one seating for dinner at approximately 7:00 p.m. Patrons must use the gondola between 5:00 p.m. and 7:00 p.m. to access the Sundeck facility. The gondola will cease operation until 9:00 p.m. and will then resume operations to download patrons between 9:00 and 11:00 p.m. The last ride down the gondola will be at 10:30 p.m. During the evening hours of operation, all necessary mountain operations staff will be provided, including lift operators, lift maintenance personnel and lift evacuation personnel. There will be no uploading of ski equipment during the evening hours and no skiing or snowboarding allowed down the mountain at night. No backcountry functions, such as cross- 0 Page 3 country skiing, are planned during night time operations. No one will be allowed to access the gondola at night who is not having dinner or working at the Sundeck facility. The banquet facilities will not be utilized during the day or the evening for business meetings or conferences. The facilities are for banquet functions only. 0 Page 4 1 9 9 7 Aspen Mountain 11aster Plan Au or u s t 1, 199 7 Employee Generation Analysis Photo of Aspen Mountain circa 1958 courtesy of Apen Historical Society Memorandum To: Brent Gardner -Smith, Planner for Community Affairs From: Chris Kiley, Transportation and Housing Planner Date: Friday, August 1, 1997 Re: ANDa Employee Generation Per the County's request, I have amended the employment figures for the 1997 Aspen Mountain Master Plan to include Bonnie's, La Baita, ACES, and the current and proposed Sundeck. I have also conducted an FTE analysis for the proposed Sundeck facility. I concur with your recommendation that we meet with Housing Director Dave Tolen to review these analyses in order to fully agree on all assumptions and calculations. 1996-97 AMen Mountain Employment — Current Conditions Aspen Skiing Company Mountain Operations Employees - Current Department Employees Full -Time. Part:: Time Lift Operations 70 62 8 Ski Patrol 31 31 0 Ticket Sales 28 14 14 Guest Services 21 13 8 Lift Maintenance 10 10 0 Snowmaking 7 7 0 Winter Trails 14 14 0 Vehicle Shop 3 3 0 Ski School 125 100 25 Ski School Admin 4 4 0 Gondola Store 4 2 2 La Baita Retail 2 1 1 Mountain Photo 30 14 16 Performance Center 5 5 0 Racing 5 3 2 Powder Tours 15 13 2 Administrative 3 2 1 Sundeck Restaurant- Winter-O 34 14 20 Sundeck Restaurant- Summer 17 7 10 Summer Operations 11 11 0 Total 439 330 109 1 Aspen Skiing Company typically uses 32 hours per week for full-time and 20 hours per week for part-time. Departments, unless noted, operate 150 days out of the year. 2 250 days per year 3 250 days per year 4 250 days per year 5 260 days per year 6 Based on 150 days of operation. Sundeck full-time shifts are 8 hours and part-time shifts are 4 hours. 7 Based on 100 days of operation. 8 4 lift ops, 3 rangers, 2 lift maintenance, 2 ticket sellers. Non -Aspen Skiing Company Mountain Operations Employees- Current The employees listed below work on Aspen Mountain for non -Aspen Skiing Company operations. Company Employees Full Time Part -Time La Badd 40 20 20 Bonnie's 54 2 52 ACES- Winter 4 2 2 ACES- Summer 2 2 0 Total 100 26 74 9 La Baita considers 40 hours per week as Fr and 20 hours as PT. 10 Bonnie's employees working 32 hours per week are considered Fr and 20 hours PT. 11 ACES full-time employees work 30 hours per week and part-time employees work 12 hours. Aspen Mountain Employment — Proposed Conditions Aspen Skiing Company Mountain Operations Employees - Proposed Department Employees Full -Time Part -Time Lift Operations 74 66 8 Ski Patrol 31 31 0 Ticket Sales 30 16 14 Guest Services 21 13 8 Lift Maintenance 12 12 0 Snowmaking 9 9 0 Winter Trails 12 12 0 Vehicle Shop 3 3 0 Ski School 125 100 25 Ski School Admin 4 4 0 Gondola Store 4 2 2 La Baita Retail 2 1 1 Mountain Photo 30 14 16 Performance Center 5 5 0 Racing 5 3 2 Powder Tours 15 13 2 Administrative 3 2 1 Backcountry Portal 2 1 1 Sundeck Rest.- Winter Day 34 14 20 Sundeck Rest. - Summer Day 17 7 10 Sundeck Rest. - Night 24 14 10 Mt Hayden Day 17 7 10 Mt. Hayden NighF 12 7 5 Benedict's Day 16 6 10 Benedict's Night` 11 6 5 Gondola Ops-Nigh 8 8 0 Summer Ops 23 19 15 4 Total 545 391 154 12 Aspen Skiing Company typically uses 32 hours per week for full-time and 20 hours per week for part-time. Departments operate 150 days per year unless noted 13 250 days per year 14 250 days per year 15 250 days per year 16 260 days per year 17 Based on 150 days of operation. Sundeck Restaurant full-time shifts are 8 hours and part-time shifts are 4 hours. 18 Based on 100 days of operation. 19 Based on a total of 75 nights of operation in summer and winter. 20 Based on 250 days of operation in summer and winter. Shift lengths are same as Sundeck Restaurant. 21 Based on 70 nights of operation in summer and winter. 22 Based on 150 days of operation in winter only. Shift lengths are same as Sundeck Restaurant 23 Based on 55 nights of operation in summer and winter. 24 Includes 4 lift ops, 2 lift maintenance, and 2 rangers for every night event at the Sundeck (200 nights). Non -Aspen Skiing Company Mountain Operations Employees - Proposed There is no change between existing and proposed employment levels for non -Aspen Skiing Company mountain operations employees. Company Employees Full -Time Part -Time La Baita 215 40 20 20 Bonnie 's 54 2 52 ACES- Winte78 4 2 2 ACES- Summer 2 2 0 Total 100 26 74 25 Includes 3 lift ops, 2 rangers, and 1 rental employee from proposed mountain bike program 26 La Baita considers 40 hours per week as FT and 20 hours as PT. 27 Bonnie's employees working 32 hours per week are considered Fr and 20 hours PT. 28 ACES full-time employees work 30 hours per week and part-time employees works 12 hours. Sundeck Expansion: Employee Generation Analysis Part One: Sundeck Facility Program and Operations Schedule The existing 1000 s.f. kitchen serves the Sundeck only. The proposed 4000 s.f. kitchen will be shared by all three and is allocated based on ratio of seats (1/2 to Sundeck, 1/4 Benedicts, 1/4 Mt Hayden) Winter Summer Lunch Dinner Lunch Dinner Existing: Sundeck Rest 150 0 100 0 Proposed: Sundeck Rest 150 30 100 45 Benedicts 150 30 0 25 Mt Hayden 150 40 100 30 100 100 Part Two: Labor Hours Per Event Shift Hours Meal Facility Position Employees Length Worked Exisitiniz Winter Lunch Sundeck Rest. Service 20 4 80 Kitchen 12 8 96 Managers 2 8 16 192 Hours/Meal Summer Lunch Sundeck Rest. Service 10 4 40 Kitchen 5 8 40 Managers 2 8 16 96 Hours/Meal NO ►• -4 Winter Lunch Sundeck Rest. Service 20 4 80 Kitchen 12 8 96 Managers 2 8 16 192 Hours/Meal Benedicts Service 10 4 40 Kitchen 4 8 32 Managers 2 8 16 88 Hours/Meal Mt. Hayden Service 10 4 40 Kitchen 4 8 32 Managers 3 8 24 96 Hours/Meal Summer Lunch Sundeck Rest. Service 10 4 40 Kitchen 5 8 40 Managers 2 8 16 96 Hours/Meal Benedicts Service 0 4 0 Kitchen 0 8 0 Managers 0 8 0 0 Hours/Meal Mt. Hayden Service 5 4 20 Kitchen 4 8 32 Managers 3 8 24 76 Hours/Meal Event Facility Shift Hours/ Position Employees (Hours) Position Winter Dinner Sundeck Rest. Service Kitchen Managers Benedicts Service Kitchen Managers Mt. Hayden Service Kitchen Managers Summer Dinner Sundeck Rest. Service Kitchen Managers Benedicts Service Kitchen Managers Mt. Hayden Service Kitchen Managers 10 4 40 12 8 96 2 8 16 152 Hours/Meal 5 4 20 4 8 32 2 8 16 68 Hours/Meal 5 4 20 4 8 32 3 8 24 76 Hours/Meal 10 4 40 12 8 96 2 8 16 152 Hours/Meal 5 4 20 4 8 32 2 8 16 68 Hours/Meal 5 4 20 4 8 32 3 8 24 76 Hours/Meal Part Three: Labor Hours By Event Schedule Hours/ Meals/ Hours/ Meal (1) Year (2) Year Existine Winter Lunch Sundeck Rest. 192 150 28,800 Summer Lunch Sundeck Rest. 96 100 9,600 38,400 Existing Hours/ Year Winter Lunch Sundeck Rest. 192 150 28,800 Benedicts 88 150 13,200 Mt. Hayden 96 150 14,400 Winter Dinner Sundeck Rest. 152 30 4,560 Benedicts 68 30 2,040 Mt. Hayden 76 40 3,040 Summer Lunch Sundeck Rest. 96 100 9,600 Benedicts 0 0 - Mt. Hayden 76 100 7,600 Summer Dinner Sundeck Rest. 152 45 6,840 Benedicts 68 25 1,700 Mt. Hayden 76 30 2,280 94,060 Proposed Hours/Year Proposed Hours/ Year 94,060 - Existing Hours/ Year 38,400 55,660 New Net Hours New Net Hours 55,660 / FTE Hours Per Year 2,080 26.76 FTE's (1) From Part One (2) From Sundeck Event Schedule 1 9 9 7 Aspen Alountain Master Plan August 1, 199 7 Traffic Analysis Photo of Aspen Mountain circa 1958 courtesy of Apen Historical Society AUG 21 '97 14:08 =R FHU 707 721 0872 TO 197092?4875 P.02%07 F E L S 8 U R G HOLT & U L L E V I GI August 1, 1997 Mr. Brent Gardner -Smith Planner for Community Affairs Aspen Skiing Company 5131 Owl Creek Road 5nowmass Village, Colorado 81615 RE: Aspen Mountain Master Plan FHU Project # 95 017 Dear Mr. Gardner-Snitti: As you requestec, we have reviewed the potential transportation and oarking 1:'rtpacts which might result from implementation of the Aspen Mountain Master Pfan_ Our repor. is attachec. We have determined that -he reconstruction of the Sundeck Restaurant and summer mountain hiking activit•Y would have *.he mo:,,t :)etential for changing patterns of use at the base of ,^a mountain and have therefore concentrated our analysis on these activitles. 3iiicir klfy, FELSBURG HOLT & ULLEVIU r� David E_ Hattan, P F. Associate S7eo:ah_mg n T:arsJG'iatlorl ar1C. Civ:l Er.cjineenrq 5299 DTC Boulevard , Suite 100 Engle•s,00d Colorado 301111 (303) 721-11.10 ni oo,? AUG 71 '97 14:08 FP FHU -03 721 a832 TO 13709234875 P. a3%©7 ASPEN MOUNTAIN MASTER PLAN OVERVIEW OF TRANSPORTATION AND PARKING IMPACTS FROM SUNDECK RESTAURANT RENOVATION, NIGHTTIME OPERATIONS, AND SUMMER ACTIVITIES The 1997 Aspen Mountain Master Plan, prepared by the Aspen Skiing Company and released in May 1997 proposes a number of improvements, almost all of which are upgrades to existing facilities. Infrastructure improvements are necessary to replace facilities which are reaching their design life or are becoming functionally obsolete. In addition; the ski area must stay competitive with other resorts in order to maintain its standing as a world -class facility. It is important to note that the Master Plan does not involve a change in the basic operations or capacity of the ski area. In fact, one of the goals contained in the Master Plan is to "improve the skiing and guest experience on Aspen Mountain without a significant increase in mountain capacity beyond the existing rated capacity of 4,300 skiers per day". Thus, it is felt that any impacts to transportation and parking systems at the base of the mountain will be limited. In reviewing the proposed Master Plan and its effect on transportation and parking, it is also important to point out that Aspen Mountain is unique. It is one of the few ski areas in the United States that doesn't have a large parking lot for vehicles at its base. Aspen Mountain adjoins the commercial area of downtown aspen, and there are numerous residences (hotels, lodges, condominiums, and single family residences) within convenient walking distance or the base area lifts. Since Aspen Mountain opened in 11946, it has become part cf the fabric of the City of Aspen. Because Aspen Mountain is so intimately tied into the fabric of downtown Aspen, it is difficult to separate out the impacts of current skier activity 4rom normal/commercial activity in the surrounding area. In order to begin to address the potentiai impacts of the proposed Master Plan improvements, this memorandum will address qualitative aspects of the concerns. More detailed, quantitative information will become available during the 1997 998 season as the Aspen Skiing Company will conduct an "origin -destination" survey of Aspen Mountain Skiers. The Master Plan proposes several changes which may have some affect on the transportation and parking systems in downtown Aspen, and these are the primary focus of this analysis. These improvements include reconstruction and expansion of the Sundeck Restaurant; evening use of the Silver Queen Gondola, Sundeck Restaurant, and La Baita Restaurant; and expansion of the terrain available for mountain biking activities in the summer. This review has oeen divided into five sections: Proposed Improvements Being Analyzed, Background and Current Conditions, Winter Daytime Operations, Winter and Summer Nighttime Operations, and Summer Daytime Operations. AUG 01 '97 14:09 FIR =HU �-0Z 721 3832 -70 197092-34875 =.04%07 PROPOSED IMPROVEMENTS BEING ANALYZED As mentioned previously, the improvements included in the Master Plan are not intended to increase the capacity of the ski area and thus will have no adverse impacts on the transportation and parking systems ir. Aspen for the most part. The following Master Plan improvements are expected to change operations to some degree and are therefore the subject of this memorandum: • Reconstruction and E4oansion of the Sundeck Restaurant - The Sundeck Restaurant is one of three restaurants at the ski area and is located at the top of Aspen Mountain. It was originally constructed in 1957 and currently includes a 7,700 square feet building. The building has a maximum seating rapacity 275 people indoors (although the practical seating is only 240) with an additional 80 people on the deck. Expansion of the restaurant to approximately 20,000 square feet was approvea in 1987. The current plan is to save part of the original building and expand it to 21,700 square feet. There would be three dining areas: a cafeteria with the capacity of 225 seats, a public sit down dining room with 100 seats, and a private sit down dining room with 100 seats. The private roam would be oparated at midday as a "lunch club" for members only. The cafeteria would serve food all day, but daytime activity at .he two dining rooms would be concentrated between 1 1 :00 a.m. and 2:00 p.m. The Master Plan envisions -hat the new building could also be used at night for group banquet service ana individual banquet style dining. Any of the three rooms .ould be reserved for grouo events. There ivouid be a moveable wail between the cafeteria and one of the dining rooms so that larger groups could be accommodated. The kitchen facilities for meal ?reparation will lir-it the maximum number of people who can be accommodated to approximately 400 diners. However, the average size of group is expected to be 75 to 100 guests. Nighttime Operation of the Silver Queen Gondola - The Siiver Queen 3ondoia would transport guests up and down the mountain rvhen there is an event at the Sundeck Restaurant. On these nights, the gondola would run from approximately 5:00 p.m. to 7:00 r.m. to bring guests up the mountain. The gondola would then run from approximately 9:00 p.m. until 1 1 :00 p.m. to bring them back down the mountain. It is expected that everyone would leave the Sundeck by 10:30 p,m. in order to be down by 11.00 p.m. Banquets could be scheduled any night of the week during the winter and summer seasons, but there would be a maximum to the total number of nights allowed during the season, as discussed In -following sections. • Nighttime Use of the La Baits Restaurant - The Master Plan includes a request to use the La Baita restaurant for a total of 10 evenings in each winter season. This will primarily consist of catering private functions and parties. The maximum guest seating capacity at La Baita is 100 people. The guests would be transported to the restaurant via snowcats. Arrival and departure times would be standardized, and guests would meet the snowcats at the Shadow Mountain Lift at standard preset times. The operation of snowcats is already occurring at these hours during full grooming operations. 2 Summer Meurtain Bike Program - Lift -served mountain biking has been conducted on Aspen Mountain or a limited, experimental basis during the summers of 1995 and 1996. Sikes were transported up the Silver Queen Gondola, and riders were encouraged to use routes along Richmond Hill or down to Castle Creek Road as opposed to using the front side of Aspen 'Mountain, The Master Alan proposes a coordinated program of lift and trail use on A.spsn Mountain during the summer with an emphasis on using new trails on the fror:t side of the mountain. ;n addition to the Silver Queen Gondola, Ajax Express and other lifts (as deemed appropriate) would be used to transport mountain bikes. A }op -to -bottom network of trails would be develooed to serve intermediate and expert ,mountain bikers. Lower mountain facilities, ;;soh as Sonn;e's Restaurant, may operatea ;n conjunction with 'he mountain biking program. BACKGROUND AND CURRENT CONDITIONS A3 mertioned previously, Aspen Mountain has a unique transportation and parking system because o' it close proximity to the City of Aspen and -hd downrowr commercial area and nearby residential areas. Parking at the base of the s{i area is very limited so Aspen Skiing Company 'ASC) inighly encourages use of alternative transportatior. ASC contributed $1,216,461 to the Roaring Fork Transit Agency ;RFTA) during the ", 995-1996 ski season for operation of the free skier shuttle. Buses run continually during, the season to Rubey Park and trarsport skiers from Snowmass Village ano, Buttermilk inn at Aspen) to downtown Aspen. Whiie many of the users of the skier shuttle are based in Aspen and use the buses to get to ana from Asper. Highlands, Buttermilk, Two Creeks at Snowmass, and the Snowmass Mail, The skier shuttles also move a significant number of skiers to Aspen Mountain. Skiers staying within the City of Aspen can also use the regular transit service which iS free on routes "rfithin the city.. '_ocal iodges also operate private vans and small buses which^ shuttle guests and groups to ana from the ski area. Taxis and limousines are also available to Aspen Mountain. skiers. =inally, there is a large `Jed base which is within walking distance of the mountain base. ASC encourages the use of mass transit by ail employees. ASC employees are able to purchase a t40 RFTA punch pass for $5 through the company, and recent surveys indicate that approximately 4011A of ASC employees regularly use transit. The number of Aspen Mountain employees using mass transit and walking to access their workplace is likely to be higher given that many live in Aspen. With regard to parking at Aspen Mountain, ASC controls two parking areas: the Aspen Street parking lot and The Little Nell Hotel parking garage. There is a 30-space parking lot on Aspen Street near the Shadow Mountain (Lift #1A) base area which is free for employees and guests on a first -come, first -serve basis. The Little Nell Hotel has an underground parking garage with 150 parking spaces: 43 spaces are currently available to skiers on a daily, monthly, and seasonal basis. In addition, day -skier public parking is available at the Rio Grande garage. There are 340 spaces in the garage at a cost of $5 per day. There is a free shuttle through downtown Aspen which provides service between the Rio Grande garage and the Silver Queen Gondola. The Galena Street Shuttle runs during the winter and summer seasons between 8:15 a.m. and 515 p.m. The two vehicies provide five to sever, minute headways along the route. AUG 01 '97 14:10 =R r=Hlf 003 721 083c TO 1?709234875 R.06%y7 Finally, there are appruxiniaLeiy 370 publiu paikiiiy SNacca uii the -Heel: ur Juwciluwn Aspen. There is a two-hour maximum time limit and a charge of $1 per hour. Paid parking hours are between 7:00 a.m. and b:00 p.m. A tew streets have overnight restrictions tar snow plowing. WINTER DAYTIME OPERATIONS The reconstruction and expansion of the Sundeck Restaurant is unlikely to have a noticeable effect On daytime transportation and parking in .aspen. The improvements are intended to replace outdated facilities, to reduce peak period llunchtimel congestion at the restaurant, and to provide guests with a better dining 3xperience (particularly at the Two sit down dining rooms) with faster service. It is not expected that additional skiers will visit .aspen Mountain because of the renovation. The Silver Queen Gongola currently tarries a limited number of "foot" passengers. These are people wno are not skiing and use the lift "or other reasons. Statistics for March 1 997 show that this amounts to approximately four percent of the total uphill activity at the ski area, it is oossible that the new Sundeck Restaurant will increase the foot traffic passengers because of the new sit down dining rooms. However, it is felt that this increase would be relatively minor, particularly in comparison with the large number of skiers using the mountain. 11 is also possible that any initial increase may taper off after peepie lave done it once er twice - depending on how unique the food and dining experience are. WINTER AND SUMMER NIGHTTIME OPERATIONS As descrioed previously, ASC is proposing that nighttime uGe of the Sundeck Restaurant would !oe Ilmlted ,.o banquets style events. ASC is requesting to be allowed -o use the Sundeck `or up to 100 nights during the winter and up to 100 nights during the summer. In addition, there is a request for up to 10 events at La Bata during the winter on y. ASC s estimating that up to 80 of the nights for the Sundeck Restaurant would be group banquet service. It is expected that there might be approximately 20 large events (up to tha 400 guest maximum - although ;t is exnPcten that the maximum ,-could be reached only once or twice a saasnn) and Fri small events (up to 10C guests). The other 20 nights would occur when no organized groups have reserved the restournnt. On these nights, service would conuist of individual banquet -style dining. It would operated much like a oanquet in that here would be a fixed menu and a set time for dining, but each small group would make individual reservations. There might be approximately 50 guests on these nights. If there are not sufficient reservations for an evening, the restaurant would not open. With regard to nighttime transportation and parking at the base of the Silver Queen Gondola, it is anticipated that a number of the larger groups could ha cnrrnrate meetinCs being held at the Ritz -Carlton, which is the largest hotel in Aspen. The Ritz -Carlton is located two blocks west of the gondola and would be within easy walking distance. For othcr.; not ztaying within walking distance of the Gondola, a number would probably avail themselves of shuttle vans operated by their lodge or use RFTA buses at Rubey Park. People driving uais wuukd Ua aUle to use on -street parking since the two-hour limit is not applicable after 6:00 P.M. However, on -street parking is currently well utilized during the winter, particularly during peak holiday periods. There are no comparable statistics available to estimate how many guests might use 4 r �L.7 J1 = -- rlJ ...__ _- L_= ll I V7G r"w I- r .V II c. each mode Uf lydnsputtai.iu+i. A ccnservati•ve estimate of the number of car3 which might require parking for the Sundeck ranges between 20 ana 80 as a maximum. Compared to the amount of parking available and the level of nighttime activity in downtown Aspen, nighttime events at the Sundeck Restaurant are expected to have only a reiatively minor impact. The 10 events requested for La Baita have already been described. the 30 parking spaces at the base of the Shadow Mountain Lift would be available for use by the guests. The remainder are expect to walk to the lift or be dropped of by shuttle vans from their Iodge. SUMMER DAYTIME OPERATIONS the primary daytime use proposed in the "Aaster Plan 4or the Summer season is expanrec mountain biking. ;appendix 6 of the Master Alan is a detailed report of mountain biking activity during the summer of 1996. 't s estimated that a total of 2.317 mountain bikes used the Silver Queen Gondola to access the mountain. ThprF %Nas an average of 42 bikes per cay with peak summer weeKends 'paving an average cr 71. The three largest days saw ' 60, 120, and a5 bikes on the gondola, reapectively. :t is reasonable to expect that Increasing the amount of terrain avoildule fur mQuiii.dirt bikiny and opening the front side of Aspen Mountain will increase the level of activity. However, no forecast of specific activity ;eveis has been developed. The new traiis on Asper Mountain are expected to serve intermediate and expert mountain bikers. Uniike skiers vvhc are relatively immobile because of ski boots, these mountain bicyclists are much more mobile and are able to ride to -ger distances to ar..r.ess trr mnitnmin. Mnst .iser. who live or are staying within _he city Would oe expected to ride t^eir "bike 'o the gondola. Others might use Ri= : A. buses, which are Cp,uipped with bike racko :wring ;'-,c spring, o-unimer, .and fall (except for routee within, .he City of Aspen) . 'hese have proved to be very popuiar with bike riders. The mai„ transit stop in Aspen at Rubey ParK is very Convenient tU the yuilduid. Otliti fIjjeIJ iiviny `urilidl awlay who drive a car would be able to parK at the Rio Grande and ,hen ride their bikes to .he gondola. On -street ,,arking would probably not be Greatly used because of the two-hour time limit. If the IAVp.i nt activity doubles. -"rem that experienced on the peak day during 1996, :t is ccnservativeiy estimated that 40 vehicles might be parked in ;he Rio Grande garage. Thus, it is cxpcotcd that day*i;ne impacts to downtown ,aspen and 'ts transportation and parking systems during the summer Niil be relatively minor, CONCLUSIONS Because the Master Plan does not involve a change in the basic operations or capacity of the Ski area, it is 'eft that any impacts to transportation and parking systems at the -base of the mountain will be limited. Specific reviews of the new Sundeck Restaurant, nighttime operations, and the summer mountain biking program also reveal that traffic and parking impacts in dcwnTovvn Aspen are expected to be relatively minor. 5 ** TOT,-L PnGE. 07 WW 1 9 9 7 Aspen Mountain Vaster Plan AU ;uSt 1, 199 i Lighting Analysis Photo of Aspen Mountain circa 1958 courtesy of Apen Historical Society 2340 Plaza Gel Amo Suite 125 Torrance California 90501 PATRICK QUIGLEY + ASSOCIATES July 29, 1997 Mr. Brent Gardner -Smith Aspen Skiing Company 5131 Owl Creek Road Snowmass Village, CO 81615 Re: The Sundeck Restaurant and Upper Gondola Terminal Buildings Lighting - Preliminary Environmental Impact Study of Existing Structures and Mitigating Measures Dear Brent: Patrick B. Quigley + Associates (PBQA) was summoned by the Aspen Skiing Company as professional lighting designers to review the environmental impact of existing and future ;fighting on the local environment. 310 533-6064 Fax 370 320-3482 The following report outlines the Sundeck Restaurant & Upper Gondola Terminal Buildings environmental setting, existing lighting systems and how these systems are used as currently operated. This section is followed by both specific, recommended mitigation measures for the existing structures, as well as general design criteria for any future nighttime use of these or other structures at this location. EXISTING CONDITIONS A. Environmental Setting - The upper Gondola Terminal Building, Sundeck Restaurant and their smaller support structures are located on the top of Aspen Mountain, in the Rocky Mountains of Colorado. The general area is characterized by low level "night sky illumination" (light pollution/light trespass) immediately surrounding the City of Aspen, fading to "black sky" conditions in the mountains past the ridge lines adjacent to the City of Aspen. There are light fixtures existing today on Aspen Mountain and they have been there for ten years, facilitating maintenance, security and low level use of both the Gondola Terminal and Sundeck Restaurant. B. Environmental Impact - The mountain top facilities can be seen at night from off -site viewpoints at isolated roads and homes around the Aspen area. Those impacted specifically include portions of; road and trail north of Hunter Creek (6 miles approx.); road north of Lenado, Larkspur Mountain and ridge between Woody Creek and the Frying Pan (10 miles approx.); Red barn on East Owl Creek Road and adjoining subdivision (6 miles approx.); Snowmass Golf Course at area of Meadow Road and intersection of Brush Creek Road and Melton Aspen Sundeck Environ. Impact 29 July, 1997 Page 1 of 7 .., Architectural Lighting Consultants 2340 Plaza Del Amo Suite 125 Torrance California 90501 310 533-6064 Fax 310 320-3482 PATRICK QUIGLEY ASSOCIATES Ranch Subdivision (subdivision north of golf course) 8 miles approx.; Hidden Meadows Subdivision north of Krabloonik Road (10 miles approx. one home visible); Conundrum Creek Trail small section visible (3.5 miles approx.� Nye house on Little Annie (.5 miles approx.). Likewise, the site can not be seen from; the Town of Aspen, Highway 82 up - valley, Highway 82 down -valley, the airport, Woody Creek, the base of Buttermilk Mountain, the base of Aspen Highlands, Ashcroft, Castle Creek Road, Maroon Creek Road and area campgrounds. If they are in the higher elevations, recreational users of the surrounding mountains such as hikers and cross country skiers may also experence a nighttime views of these facilities. Though these views are extremely limited, they are of significance due to the area's historic preference for an uninterrupted silhouette of the mountain ridges against the night sky. The minimal use of exterior fixtures means that these buildings' contribution to the night sky illumination is nominal. Any such contribution is overwhelmed by the street and facade lighting of Aspen City below. II. CURRENT OPERATIONS AND SPECIFIC MITIGATION A. The Gondola Terminal Building Current operations at the Gondola Terminal Building include nighttime security and maintenance activities, as well as transporting patrons to the restaurant. Existing illumination systems and recommended mitigation include: Gondola Building Exterior: a) A single high intensity discharge (HID) "wall pack" type fixture mounted on the west facade, overlooking the public entry portal. This fixture type is characterized by high glare and indiscriminate light distribution toward the horizontal ground plane, the sky, and everything in between. Mitigation calls for this fixture's replacement by a well shielded unit that directs its light toward the ground plane only. b) The vehicle maintenance facility at the east end of the structure has a large roofed, open sided staging area. The area is now used at night in the winter. Mitigate by using shielded fixtures that limit illumination to the ground plane, such as a "long barreled" ceiling mounted down light. Aspen Sundeck Environ. Impact 29 July, 1997 Page 2 of 7 Architectural Lighting Consultants 1340 Plaza Del Arno Suite 115 Torrance California 90501 310 533-6064 Fax 310 310-3481 <'cn PATRICK QUIGLEY + ASSOCIATES 2. Gondola Building Interior: a) The building interior lighting is made up entirely of non -shielded fixtures including bare fluorescent strips and incandescents in the office and tunnel (where cabins first enter the facility), and HID "wall packs" in the loading room and gondola storage areas. While the cumulative systems provide an appropriate level of work light, their use also results in a very high level of interior glow as seen from outside the structure. Specific mitigation measures should include mechanized shading devices in the loading area located along the south facades window wall. The same technique should be used at any window exposed to an off site view, such as the office. These shading devices should be controlled bya photo cell or timer device. b) Eight of the HID wall packs in the loading area are left on all night for security purposes and provide a reasonable level of light. The mitigation noted above will negate the current impact of this all night system. 3. Additional Illumination of Gondola Cabs: If night use is approved, then additional illumination should be provided between the Gondola Terminal Building and the last tower for operators to see whether the cabs are swinging due to high winds. Mount an HID, low wattage, narrow flood at tunnels' north exterior facade. Equip fixture with louver and/or other glare mitigation device. Alternative location is under the arrival portal, on the wall, to uplight incoming cabs. B. The Sundeck Restaurant Current operations include dining for individual groups on an extremely limited, special permit basis. All lighting systems stay on for clean-up followed by a late night security setting. In the winter, kitchen and snack bar lighting along with selected circuits facilitating access, are used by the prep cooks who often work until late into the evening. Sundeck Restaurant Exteriors: Aspen Sundeck Environ. Impact 29 July, 1997 Page 3 of 7 Architectural Lighting Consultants 2340 Plaza Del Amo Suite 12 5 rorrance California 90501 310 533-6064 Fax 310 320-3482 PA TRICK aUIGLEY + ASSOCIATES a) "Jelly jar" incandescent fixtures are mounted on the walls adjacent to the south and southwest facing sundecks. Though low wattage, these fixtures are similar to "wall packs" in their omni-directional light distribution and indiscriminate glare. These units are among the most visible fixtures from off -site views and are currently left on ail night. These fixtures should be either shielded or replaced with new, glare controlled down lights resulting in illumination of the horizontal plane of the deck only. b) Ceiling mounted wail pack at north covered stairway is baffled from exterior view except at flanking windows. Mitigate by supplying a shielding collar. c) Tents - Currently large tent structures are available for banquets during the summer only. Use of these tents is extremely limited by the same special use permit requirement that governs the restaurant. The restaurant and tent seating is not used concurrently. The impact of the tent(s) at night can be effectively mitigated through proper siting based on offsite views and through opaque flaps hung on sides visible from off site. 2. Sundeck Restaurant Interiors: a) The two levels of interior seating are lit primarily by adjustable, incandescent ceiling mounted "mono point" fixtures. They are arranged in two, octagonal donuts in plain view at approximately 6' and 12' from the perimeter wall. Some of the fixtures are currently aimed such that direct lamp glare is seen from outside. The obvious mitigation for this system is to aim these fixtures universally away from the windows and toward the room's interior. This alone, however, leaves the perimeter tables against the window unlit. PBQA recommends adding an additional donut of fixtures immediately adjacent to the perimeter wall. These fixtures should be aimed away from the glass while still being able to illuminate these tables. The new fixtures will provide an added daytime benefit - - helping skiers adjust from the intnse sunlight outside to the relative darkness of the restaurant. b) The innermost of the interior octagon forms is currently lit by soffit mounted up lights. Due to the exterior visibility of the lit ceiling plane, we advise: a) Dimming this CKT down significantly, or b) Replacing with a new system of low voltage down lights that illuminate the inside faces of the columns, as well as the columns at the fireplace. The two systems Aspen Sundeck Environ. Impact 29 July, 1997 Page 4 of 7 Architectural Lighting Consultants 2340 Plaza Del Amo Suite 115 Torrance California 90501 310 533-6064 Fax 310 320-3482 In PATRICK QUIGLEY + ASSOCIATES could be used together. c) "Wrap around" lensed fluorescent fixtures, ceiling mounted over slack bar is a source of high glare. Install a wood frame around the fixture and equip with 1/2"xl/2"x1/2" white acrylic "eggcrate" louver. FUTURE OPERATIONS AND ACCOMPANYING LIGHTING MITIGATION CRITERIA PBQA's understanding of future operations as proposed by the Aspen Skiing Company is for a year round banquet dining facility, open up to seven nights a week with the last down mountain Gondola cab at 10:30 P.M. The facility would be booked on demand. If all of the specific mitigation measures listed in previous sections of this report are acted on, the result will be a significantly reduced impact to the nighttime view corridors toward the structures. Whether the operating hours are extended or not, the direct glare of lamps and interior glow at night will be greatly reduced from current levels. In addition, sky illumination should be the same or less than existing levels due to properly shielded fixtures. Besides the mitigation previously mentioned, we believe the following items represent important additional design criteria. Regardless of what agreement the Aspen Skiing Company and the Community may come to, these criteria will help ensure a sensitive nighttime treatment of this delicate environment. A. The lowest applicable Illuminating Engineering Society's (IES) recommended footcarxdle (FC) levels should be provided, -walkway and decks at .2 FC with illumination uniformity ratios of 4:1 to 6:1 (average to minimum). B. Wherever possible, screening features such as trees, berms, walls, topographic features and architectural elements should be utilized to hide fixtures from view and trap light at the ground plane. C. To minimize the lighting's impact, the fixtures used will feature the following characteristics: Low levels of lighting provided by "warm" toned (2,500 to 3,000 degrees Kelvin temperature) lamps. 2. Physical characteristics of lighting equipment shall be forms, materials and finishes that are compatible with the adjacent surroundings (i.e. wood posts, earth tone finishes, stone). Aspen Sundeck Environ. Impact 29 July, 1997 Page 5 of 7 Architectural Lighting Consultants 2340 Plaza Del Amo Suite 12 5 Torrance California 90501 PATRICK QU/GLEY ASSOCIATES 3. Fixtures shall have distribution types and cut-off characteristics thatlimit spill light onto vertical surfaces such as plants and buildings that can be seen from off -site. The fixtures used shall typically be of a shielded downlight variety. To prevent glare, fixtures shall have optical control based on proper placement of light source within fixture and proper design of reflector and lenses. Glare mitigation devices such as baffles, louvers and shields will be used as required. D. Fixtures shall be oriented to minimize off -site impact (i.e. the maximum candlepower shall be aimed away from the off -site viewer and the physical unit shall be located on the shielded side of visual barriers, such as trees and walls). E. Exterior and interior building materials shall be non -reflective and use natural, subdued tones. 3 1 0 533- 6064 F. Lighting of signage shall be kept to the minimum practical footcandle level required for F a x 3 1 0 31 0 - 3 4 81 successful identification of destinations. All sign lighting, , if required at all, shall utilize non -glare down light fixtures. No neon or self -illuminated signage shall be permitted. G. Other than signage, no direct vertical illumination, such as facade washes or landscape accent lighting, shall be allowed within the off -site view condors into the project. H. Impacts from night -lighting on wildlife in neighboring habitats shall be resolved through shielding, directing lights away from adjacent open space, using lower -intensity lights, and using automated controls to limit light usage to those times it's needed for guest use and maintenance, followed by lower levels needed for late night safety and security. Though a lower overall impact can be expected on nocturnal wildlife if all mitigations are followed, PBQA's lack of familiarity with local species precludes us from commenting on this subject in an authoritative manner. IV. CONCLUSION As the two facilities exist today, little, if any glare or night sky illumination mitigation exists. The fixtures are bright and have some impact on distant views and nocturnal wildlife. Even so, the view corridors into the project are extremely limited and, in most cases, quite remote. We are comfortable saying that if the specific glare mitigations and design criteria are followed off site views to the projects will be reduced. The views that remain will be noticeably and positively impacted by significant glare reduction. Whether the restaurant hours are extended or not, the cumulative mountain top facilities will have a reduced environmental impact from the existing conditions. Indeed, if the Gondola Terminal and Sundeck are used for nighttime operations and the recommended mitigations are implemented, the likely impact will be less Aspen Sundeck Environ. Impact 29 July, 1997 Page 6 of 7 Architectural Lighting Consultants 2340 Plaza Oei Amo Suite 125 'orrance California 90501 310 533-6064 Fax 310 320-3482 PATRICK QUIGLEY + ASSOCIATES than currently exists. PBQA anticipates lower levels of night sky illumination if these measures are adopted and the operations stay the same. Or about the same level as exists today if operations are expanded as described by the Aspen Skiing Company, and noted in this report. Respec Ily submitted, Patrick Quigley Aspen Sundeck Environ. Impact 29 July, 1997 Page 7 of 7 Architectural Lighting Consultants 1 9 9 7 Aspen Mountain faster Plan August 1, 1997 Surveyor's Report Photo of Aspen Mountain circa 1958 courtesy of Apen Historical Society