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HomeMy WebLinkAboutDRB130095 APPLICATION.pdf RECEIVED Department of Community Development 0 Date: 0 4/0 8/2 013 @ 9 : 0 2pm 75 South Frontage Road 0 TOWN OF mu TOWN OF VAIL ' B Vail,9 CO 81657 Y D. RHOADES Te1: 970-479-2128 www.vailgov.com Development Review Coordinator Application for Design Review Additions - Residential or Commercial General Information: This application is required for all proposals involving the addition of any floor area, including net floor area and/or gross residential floor area (GRFA). This also includes proposals for `residential 250 additions' and 'interior conversions'. Applicable Vail Town Code sections can be found at www.vailgov.com under Vail Information — Town Code Online. All projects requiring design review must receive approval prior to submitting a building permit application. An application for Design Review cannot be accepted until all required information is received by the Community Development Department, as outlined in the submittal requirements. The project may also need to be reviewed by the Town Council and/or the Planning and Environmental Commission. Design review approval expires one year from the date of approval, unless a building permit is issued and construction commences. Fee: $300 V Single Family Duplex Multi-Family Commercial Description of the Request: Remodel and Addition of an existing chalet style house on Sandstone Drive in Vail. Extensive improvements to the exterior facade, railings, and entrance. Expanded patio. 2-story addition. Addition of 1,040 sq ft of GRFA(Residential) or sq ft of net floor area (Commercial/ Office) Physical Address: 1079 Sandstone Drive#W,Vail, CO Parcel Number: 2103-014-12-005 (Contact Eagle Co. Assessor at 970-328-8640 for parcel no.) Property Owner: Nathaniel& Mary Ford Mailing Address: 1900 16th Street, Su. 1400, De r, CO 80202-5255 Phone: Owner's Signature: Primary Contact/O r Representative: John G. Martin,Architect(Martin Manley Architects) Mailing Address: PO Box 4701, Eagle, CO 81631 Phone: 970-328-0592 E-Mail: John @martinmanleyarchitects.com Fax: For Office Use Only: Cash CC: Visa/ MC Last 4 CC# Exp. Date: Auth # Check# 2 514 Fee Paid: $300 . 00 Received From: JOHN G. MARTIN Meeting Date: DRB No.: DRB 13 0 0 9 5 Planner: Project No: PRJ13-0109 Zoning: Land Use: Location of the Proposal: Lot:A-3W Block: Subdivision: LIONS RIDGE TOWN OF VAIL JOINT PROPERTY OWNER WRITTEN APPROVAL LETTER The applicant must submit written joint property owner approval for applications affecting shared ownership properties such as duplex, condominium, and multi-tenant buildings. This form, or similar written correspondence, must be completed by the adjoining duplex unit owner or the authorized agent of the home owner's association in the case of a condominium or multi-tenant building.All completed forms must be submitted with the applicants completed application. f, (print name) 14`Gx eq ez 4 a joint owner, or authority of the association,of property located at 1079 Sandstone Drive#w,va i,CO provide this letter as written approval of the plans dated April 8,2013 which have been submitted to the Town of Vail Community Development Department for the proposed improvements to be completed at the address noted above. I understand that the proposed improvements include: 1,040 sq. ft. 2-story addition on the north (rear)side of the chalet house. Including 2 roof dormers. Exterior improvements include siding materials, railings, entry door&walk, and the addition of a stone wainscot. Existing Vilest Deck(main level)to be expanded to the west. Interior improvements to layouts, finishes, and fixtures throughout. I understand that modifications may be made to the plans over the course of the review process to ensure compliance with the Town's applicable codes and regulations; and that it is the sole responsibility of the applicant to keep the joint property owner apprised of any chan sr and ensure that the changes are acceptable and appropriate. Submittal of an application esuIJq in the applican greZ to this statement. J , f- /1" f�j r -�3 nat Sig Date �V Rita Print IVam Property Information Property Address 1079 Sandstone Drive#W, Vail, CO Parcel# 2103-014-12-005 Legal Description Lions Ridge Filing 1, Lot A-3W Development Site Area sq ft acres 41,129 .94 buildable sq 41,120 ft Zone District/SDD# Residential Cluster(RC) Hazard Zones Snow Avalanche High Severity Moderate Severity r N/A Sections 12-21& 14-7 Debris Flow High Flow Moderate Flow High Avalanche j7 N/A Rock fall High Severity , Medium Severity N/A Excessive Slopes ?30% N/A Floodplain 100 year floodplain Floodway Wetlands N/A Creeks,Streams Gore Creek - on site r adjacent to site v N/A Section 12-14-17 Other tributary: on site adjacent to site N/A Project Information Project Description Remodel and Addition - Facade and railings facelift, 2-story addition in back Development Standards Allowed Existing Proposed Gross Residential Floor Area Primary sq ft 5,611 4,471 +1,040 = 5,511 (maximum) Secondary sq ft Chapter 12-15 EHU sq ft TOTAL sq ft 5,511 250 Addition Interior Conversion Credits: Setbacks(minimum) Front ft 20 Section 14-10-4 Side ft 15 Side ft 15 Rear ft 15 Watercourse ft Site Coverage(maximum) 10,280 2,659 +520 = 3,179 see definition Section 12-2-2 Building Height(maximum) Sloping ft 33 33 33 see definition Section 12-2-2 Flat ft Landscaping Softscape sq ft NA See definition Section 14-2-1 Hardscape sq ft NA Section 14-10-8 TOTAL sq ft NA Driveway Max Curb-cuts NA Sections 14-3-1& 14-3-2 Max Grade @ cen- terline NA Min Width NA Heated drive? Yes No rYes j , No Snow Storage% NA Parking #Enclosed Spaces Sections 12-10&14-5 #Unenclosed 4 + 2 = 6 TOTAL Outdoor Lighting(maximum) #fixtures Section 14-10-7 UTILITY APPROVAL&VERIFICATION This form serves to verify that the proposed improvements will not impact any existing or proposed utility services,and also to verify service availability and location for new construction and should be used in conjunction with preparing your utility plan and Schedul- ing installations. A site plan, including grading plan,floor plan, and elevations, shall be submitted to the following utilities for approval and verification. PLEASE ALLOW UP TO 2 WEEKS FOR APPROVAL OR COMMENTS FROM THE UTILITY COMPANIES. If you are unable to obtain comments within that timeframe please contact The Town of Vail. Subject Property Address: 1079 Sandstone Drive#W Lot A-3W Block 1 Subdivision: LOO-Idge Laap Primary Contact/Owner Representative: John G. Martin, Architect Phone: 970-328-0592 Primary Contact/Owner Representative Signature Plans Dated: Authorized Signature Comments Date CENTURY TEL 970.468,6860(tel) 970.468.0672(fax) Contacts: Samuel Tooiey saLnuel.tooley(acenturylink.com XCEL HIGH PRESSURE GAS 970.406.1309 (tel) 970.468.1401 (fax) Contact: Ron Bureta ronnie.j.buretaCc2xcelenergy.com HOLY CROSS ENERGY 970.947.5471 (tel) 970.945.4081 (fax) Contact: Jeff Vroom jvroom@holycross.com XCEL Energy 970.262.4038 (fax) 970.262.4050(tel) Contacts: Louise Timson louise.timson xcelener .corn EAGLE RIVER WATER&SANITA- TION DISTRICT 970.477.5435 (tel) 970.477.5434 (fax) Contact: Tug Birk tbirk@&nmsd.org COMCAST CABLE 970.390.4713 (tel) 970.468.2672 (fax) Contact: Michael Johnson Michael-johnson@cable.comcast.com CDOT(Only in CDOT Right-of-way) 970.683.6284(tel) Contact: Dan Roussin Daniel.roussin @dot.state.co.us 1. Utility locations must be obtained before digging. NOTES: 2. A Revocable Right-of-Way Permit may be required for any improvements within a street right-of-way. Contact the Public Works Department for verification 970.479.2198. 3. It is the responsibility of the utility company and the applicant to resolve problems identified above. 4. The Primary Contact/Owner Representative is required to submit any revised drawings to the above agencies for re-approval &re-verification if the submitted plans are altered in any way after the authorized signature date. UTILITY APPROVAL&VERIFICATION This form sorves to verify that the proposed improvements will not impact any existing or proposed utility services,and also to verify service availability and location for new construction and should be used In conjunction with preparing your utility plan and schedul- ing installations. A site plan,including grading plan,floor plan,and elevations,shall be submitted to the following utilities for approval and verification.PLEASE ALLOW UP TO 2 WEEKS FOR APPROVAL OR COMMENTS FROM THE UTILITY COMPANIES. If you are unable to obtain comments within that timeframe please contact The Town of Vail. Subject Property Address: 7679 Sandstone Drive#W LotA-3W Block 1 Subdivision: Primary Contact/Owner Representative: John G. Martin,Architect phone: 970-328-0592 Plans Dated: 3-6-13 Primary Contact/Owner Representative Signature Authorized Signature Comments Date CENTURY TEL 970.468.6860(tel). 970.468.0672(fax) Contacts: Samuel Tooley samuel.tooley(o�centuiylink.com XCEL HIGH PRESSURE GAS f 40 C.br! �frG (,;r la�s1- yes 970.406.1394(tel) 970.468.1401 (fax) Contact: Ann i r U re�ie,�.E3trrcfi r,e or+ L e HOLY CROSS ENERGY 970.947.5471 (tel) 970.945.4081 (fax) Contact: Jeff Vroom jvroom @holycross.com XCEL Energy 970.262.4038(fax) 970.262,4050(tel) Contacts: Louise Timson louise.timson @xcelenergy.com EAGLE RIVER WATER&SANITA- TION DISTRICT 970.477,5435(tel) 970.477.5434(fax) Contact: Tug Birk tbirk@erwsd.orq COMCAST CABLE 970.390.4713(tel) 970,468.2672(fax) Contact: Michael Johnson Michaeljohnson@cable.comcast.com CDOT(Only in CDOT Right-of-way) 970.683.6284(tel) Contact: Dan Roussin Daniel.roussin @dot.state.co.us NOTES: 1. utility locations must be obtained before digging. 2. . A Revocable Right-of-Way Permit may be required for any improvements within a street right-of-way. Contact the Public Works Department for verification 970.479.2198: 3. It is the responsibility of the utility company and the applicant to resolve problems identified above. 4. The Primary Contact/Owner Representative is required to submit any revised drawings to the above agencies for re-approval &re-verification if the submitted plans are altered in any way after the authorized signature date. UTILITY APPROVAL &VERIFICATION This form serves to verify that the proposed improvements will not impact any existing or proposed utility services, and also to verify service availability and location for new construction and should be used in conjunction with preparing your utility plan and schedul- ing installations. A site plan, including grading plan,floor plan, and elevations, shall be submitted to the following utilities for approval and verification. PLEASE ALLOW UP TO 2 WEEKS FOR APPROVAL OR COMMENTS FROM THE UTILITY COMPANIES. If you are unable to obtain comments within that timeframe please contact The Town of Vail. Subject Property Address: 1079 Sandstone Ddve #W LotA-3W Block 1 Subdivision: "°"s"dge`° Primary Contact I Owner Representative: John G. Martin, Architect Phone: 970-328-0592 Plans Dated: 3-6-13 Primary ContactlOwner Representative Signature Authorized Signature Comments Date CENTURYLINK 970.328.8288(tel) 970.328.8282(fax) Contacts: Barb Davis barb.davis@centurylink.com XCEL HIGH PRESSURE GAS 970.406.1309(tel) 970.468.1401 (fax) Contact: Ron Bureta ronnie.j.bureta xce energy.corn HOLY CROSS ENERGY 970.947.5425 (tel) 970.945.4081 (fax) � / 3/11/13 Contact: Jeff Vroom 'vroom hol cross.com XCEL Energy 970.262.4039 (tel) 970.262.4038 (fax) Contacts: Pam McGuire amela.mc uire xcelener .com EAGLE RIVER WATER&SANITA- TION DISTRICT 970.477.5449 (tel) 970.845.7218 (fax) Contact: Tug Birk tbirk erwsd.or COMCAST CABLE 970.930.4713 (tel) 303.603.1004(fax) Contact: Michael Johnson Michael 'ohnson cable.comcast.com CDOT(Only in CDOT Right-of-way) 970.683.6284(tel) Contact: Dan Roussin Daniel.roussin @dot.state.co.us NOTES: 1. Utility locations must be obtained before digging. 2. A Revocable Right-of-Way Permit may be required for any improvements within a street right-of-way. Contact the Public Works Department for verification 970.479.2198. 3. It is the responsibility of the utility company and the applicant to resolve problems identified above. 4. The Primary Contact/Owner Representative is required to submit any revised drawings to the above agencies for re-approval & re-verification if the submitted plans are altered in any way after the authorized signature date. MART I N M AN LEY ARCHITECTS Memo To: Nate Ford 303-291-2336 nford(@perkinscoie.com From: John G. Martin 970-328-0592 john @martinmanleyarchitects.com Date: April 30, 2012 Re: 1079 Sandstone Drive- East and West Lots Subj: Town of Vail—GRFA Zoning Information Zoning: RESIDENTIAL CLUSTER (RC) DISTRICT 2 HOUSES SHARE SINGLE LOT FOR CALCULATING ZONING LIMITATIONS Site Area: 2 Lots Combined = 41,120 s.f. Buildable Area: 15, 588 s.f. (from old survey indicating 40% slopes) GRFA: Allowed: 5,611 s.f. (max 36% of"buildable area") Existing: 4,471 s.f. (both lots combined 1,975 s.f. + 2,496 s.f.) Available: 1,140 s.f. West House GRFA = 1,975 s.f. (44%) East House GRFA = 2,496 s.f. (56%) Total Existing = 4,471 s.f. Site Coverage: Allowed: 10,280 s.f. (max 25% of total site area) Existing: 2,659 s.f. (both lots combined) Available: 7,621 s.f. Landscape and Site Development: Allowed: 24,672 s.f. (min 60% of total site area) Existing: Not Known Parking: No change. Height: 33 feet (conforming) —FFWW97032&5151 martinmanleyarchitects.com • 0 Box 1587 Lagle, Colorado N 0 Nti MARTIN MANLE 'Y ARC"ITECTS Nate Ford Renovation + Addition—Vail Colorado Material & Color Board 4-3-13 �..,� Roofing: Cedar Wood Shingles 74, 'r r � �^ to match existing Roofing: Standing Seam Metal 4 Drex Metal—Lowest Reflective Finish Coating 323 MANSARD BROWN* Color: "323 Masard Brown" Wood Siding: Horizontal Ship Lap 4 Color: Sherwin Williams Solid Stain Yankee Barn 5W 3505 "SW 3505 Yankee Barn" Trim, Beams, Posts, Exposed Rafters, Soffit, &Railings: 4—Color: Sherwin Williams Solid Stain fi SW 3507 Riverwood" Riverwood SW 3567 Q Stucco Siding: Color: Match El Rey Standard Color 121 Sandalwood" z Q Stone Veneer: Random Ashlar Pattern Match Gallegos Stone Pattern: #54 Highlands Beaver Creek Blend Window Clad Color: To match existing cool grey 4 March 18, 2013 Trent Hubbard, Contractor, on behalf of Nate Ford, Owner 1079 Sandstone Drive Vail CO 81657 Re: Rockfall Potential, Proposed Addition to 1079 Sandstone Drive, Vail, Colorado, Dear Mr Hubbard: At your request, I have examined the area that is a concern for potential rockfall damage and/or injury to your proposed house addition. Following are my results and conclusions. SUMMARY There is a small potential for damaging and/or personally injurious rockfall at the subject site. Although the magnitude of potential damage from a single falling rock could be large, the sources of potential falling rock are minor. Rockfall events are sporadic over time, and it is not possible to predict any times of occurrence or the specific paths of any future rockfall events. If a greater level of assurance is desired, the uphill portion of the addition may be designed for the potential rockfall loadings. SOURCES OF INFORMATION The site was investigated using USGS maps, other published literature, Google Earth images, visual examination and photography, and by computer modeling of the most likely potential rockfall events. SITE LOCATION The site lies at the northern edge of Vail Village, and the lot lies entirely within a designated zone of high rockfall hazard potential. The potential source of rockfall is the hillside to the north of the lot. The proposed addition would be on the northern, uphill side of the house, and would therefore be the most likely portion of the house to suffer first impact from a future rockfall event. The addition covers 29 feet of the 52 foot width of the house. Proposed addition and house are both of standard residential wood frame construction. Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 2 of 10 The portion of the hill that is of principal concern as a potential source of falling rock is the portion that lies directly up the slope from the addition, perpendicular to elevation contours. It extends in a narrow zone (less than 30 feet wide) approximately 1100 feet horizontally to the northwest and approximately 535 feet vertically up the hill from the addition. It comprises slightly less than % of an acre. TOPOGRAPHY Topographic information was principally obtained from the USGS Vail West 7.5 minute topographic quadrangle map. A small amount of the topographic data was taken from a recent lot survey by Eagle Valley Surveying, Inc. A plan view with composite contours follows. The overall mountain rises to about 10,325 feet elevation, but the portion directly uphill subpeaks at a ridge at 8825 elevation. The grade adjacent to the proposed dwelling addition would lie at an elevation of approximately 8290 feet. The average slope gradient from the house site at the valley bottom to the top of the zone of interest, about 535 feet up, is about 49%, or about 260 . POTENTIAL ROCKFALL PATH The most likely potential path for falling rocks to follow in arriving at the dwelling is defined by the perpendiculars to the slope contours, since the reaction of the slope against the falling boulders tends to push them out in that perpendicular direction. Contours from the USGS topographic map that were used to define the travel path have been superimposed on a satellite image to illustrate the rockfall area in an overhead plan view Site Plan, next page. The zone directly above the dwelling that provides direct perpendicular travel paths to the dwelling has been outlined in red. Irregularly shaped blocks may bounce in irregular ways as they impact the slope at odd angles, and local irregularities in the ground surface may cause the same effect. These irregularities allow blocks originating within the defined travel path to bounce elsewhere, and they also allow blocks originating elsewhere to bounce into the defined travel path. Nevertheless, most travel will be guided along the perpendicular direction, deviations will be relatively random, and boulders travelling into the defined path should approximately compensate for boulders travelling out and away from the path. Analysis of the direct travel path above the dwelling is therefore reasonable. In the Site Plan, a heavy blue line down the approximate center of the travel path has been used to profile the slope and to provide an input geometry for a computer analysis of potential Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 3 of 10 + Y a j ,;� � • �- ear` � � , a f+� �� ., . .. ir • , �F f a s, �' a � ��i • '�. i r 'J a . a ino. W,.4 �,. r. l . . t •, _ ` 11EN11AL �= ti + - X 40. '♦ " tor 4 J!w� a r.r �� d C [ � • . o " t--=i • 0 zoo X00 5CAI� 1" - 200' COVOT, IN11FpVA- 40' ALL �LIUu r PLC 5ITF, FLAN LoaJville, Col area Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 4 of 10 rockfall dynamics. The profile along this line is shown on a Slope Profile drawing, which has been appended as an oversize sheet on Page 10 following the report text. GEOLOGY The hillside at this site has been mapped by the US Geological Survey as a layered sequence of sedimentary rocks, with an overlying veneer of glacial till in some lower areas. Even within USGS publications, some of the data is conflicting, and no field study has been undertaken to resolve any conflicts. Some of the spatial data, in particular, should therefore be taken to be approximate. The only bedrock unit of interest for rockfall at this site is the Pennsylvanian Minturn Formation, which underlies the entire inferred source area for potential falling rocks and dips north-northwest at about 18°. The Minturn is a sequence of dirty sandstones with lenses and layers of limestone and carbonate-rich sands. The sandstone, siltstone and mudstone layers generally weather to smaller fragments and contribute fewer boulders to the hillside, while the carbonates possess more integrity and forms more of the boulders. The topmost unit of the Minturn here is the Jacque Mountain Limestone Member, a thin (40 to 50 foot thick) unit which coincidentally marks the ridgeline just above the extreme top of the potential rockfall zone, at approximate elevation 8825. It is one of the principal boulder- forming units on the hillside, but appears to be either completely above the subject rockfall zone or else so limited in the intersection of its basal units with the rockfall path that its contribution to the rockfall zone should be minor. The glacial till mantle in the lower half of the rockfall zone provides a soil mantle that retains moisture and supports a significant aspen forest. This forest has developed a more mature soil with fewer boulders, and the trees and undergrowth probably also inhibit smaller boulders from gaining momentum. The forest extends for a way uphill from the glacial till as well. COMPUTER MODELING OF POTENTIAL FOR DAMAGE FROM ROCKFALL EVENTS The Colorado Rockfall Simulation Program was used to model the potential for occurrence of rockfall damage on this site. This program was first developed in 1984 through 1989 as funded research at the Colorado School of Mines to deal with the numerous rockfall design problems facing CDOT. Since then it has been expanded and updated, validated and verified by field testing, and used from California and Oregon to Switzerland. The program has been extensively reviewed and tested and calibrated to field data, and is used by mines and public road agencies. The principal input for this site is the profile of the hillside that was created from the topographic map. Randomly generated rockfall events are initiated by the program on the profiled hillside and their progress falling down the hillside is calculated by the program. The Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 5 of 10 slope was divided into 19 segments based on varying steepness and hardness of the rock or soil or degree of vegetative cover. Other program input parameters include starting zone, rock size, rock shape, rock density, surface roughness, tangential coefficient of friction, and normal coefficient of restitution. Output results include velocities, bounce heights, kinetic energies, and where the rocks stop rolling. Specific points may be selected for analysis of output data. Rock sizes of 2 to 4 foot diameter were selected for analysis, based on rocks observed at the site. Most of the boulder-forming units have boulders of that size available. Rock density was set to 165 Ibs/cu ft, which is an intermediate value for a carbonate rich layer. The remaining factors have been mostly empirically derived from comparison to actual rockfall behaviors at other sites. Surface roughness factor reflects a mixture of both slope roughness and boulder irregularity. The worst case, a roughly spherical boulder is assumed. Surface roughness here was set to 3 to 6 inches for the 2 foot boulders and 6 to 12 inches for the 4 foot boulders, to account for irregularities in the slopes and in the shapes of the boulders. The surface roughness parameter was set to the lower value for the lower portion of the path where a boulder may have lost some of its asperities. Tangential friction and normal restitution were set to a reasonable range of values, as typical of bedrock, firm soil or forest soil slopes at other sites. Each bounce of a boulder tends to slow it down or stop it, unless the slope is sufficiently steep to overcome the soil damping and accelerate it further along on its way. Boulders will fairly quickly roll to a stop on flat ground. A series of runs were done, for upper and lower boulder source segments, to check the potential for hazards from the various rock zones along the profile. This showed that 2 foot diameter boulders from the top boulder zone at 8800+feet were unlikely to travel to slope bottom. About 4% of the larger boulders in the top zone would be expected reach the addition, with the great majority being stopped by the damping from forest soils. After struggling through the forest, the few survivors quickly build speed again in the bare lower slope area. The lower source was capable of delivering any well-rounded boulders to the slope bottom and on into the dwelling. These lower source boulders could build speed quickly and could be just as damaging as ones from above. The program randomly initiates a thousand boulder movements within an outcrop source zone and then tabulates the ensuing results for all of the boulders into a statistical representation of probable behavior. The upper source runs were analyzed at 3 points: the upper edge of the forested area, the lower exit from the forested area, and the north wall of the addition. It was found for all runs Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 6 of 10 that all boulders that were successfully initiated (about 85%) accelerated rapidly through the upper bare area and into the forest, then were decelerated by the damping effect of soft forest soils. None of the smaller boulders escaped the forest area, but the very few larger boulders that did make it all the way through the forest were rapidly re-accelerated down to the house. The median calculated characteristics of potential rockfall boulders reaching the slope at bottom of forest and reaching the north wall of the addition are tabulated below: Elevation Diameter Percent Percent Mean Mean Mean of of Rock Arriving Arriving Velocity Bounce Height Kinetic Energy Origin (feet) Bottom at House (fps) (feet) (foot-pounds) 8825 2 0 0 -- -- -- 8825 3 4 4 43 1 91,000 8825 4 5 5 40 1 185,000 8375 3 -- 85 38 1 74,000 The calculated energy levels in the boulders that do reach the house are probably sufficient to penetrate standard wood frame walls or knock them down and structurally damage the house. If a rock were to hit at a critical load support location, much of the structure might collapse. The house walls would probably not significantly alter the progress of the boulder unless it were to hit a major structural impediment. SITE SPECIFIC OBSERVATIONS The slope above the addition is convex in overall horizontal plan. This geometry reduces the width of the potential rockfall path as it is traced up the hillside, from 29 feet wide at the bottom to zero width at some point near the top. Boulders that roll down the hillside outside of that path will tend to roll elsewhere. The path traverses areas of sparse vegetation and relatively thin soil cover at top and bottom, but the middle area, comprising about 47% of its length, is forested to varying degrees. The lower portion of the forested area has a thicker organic soil layer developed on glacial moraine, and many of its aspen reach diameters of 9 or 10 inches. While the larger aspen are too sparse to impede most rockfalls, the thicker, softer soil in which they thrive, along with the locally slightly shallower slope angle, are effective dampers to rockfall progress. The path maintains an overall average gradient of about 49%, which is an angle of about 26 degrees, a slope that is sufficiently steep for carrying and accelerating rockfalls if the soils are firm or thin or absent and the surface is relatively uniform. It is not, however, sufficiently steep to propagate rockfalls if the soil is thick and relatively soft. Forest vegetation is a further decelerating factor. At this relatively shallow slope angle, with fairly smooth slopes and short available acceleration distances that are sparse of forest soil and vegetation, the boulders Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 7 of 10 would tend to stay close to the ground and roll as much as bounce in their descents. Few bounces are expected to exceed 2 or 3 feet in height. This particular potential rockfall path has two principal rockfall sources, and the available width of each source outcrop is small. The horizontal outcrop width between rocks suitable for rolling downhill is generally much greater than the path width. Slope areas vertically in-between the two sources do not appear to produce significant boulder-forming outcrops. The top source (at 8825 elevation) may not be capable of providing any boulders to the rockfall path at all, since map analysis indicates the rockfall path goes to zero width at its intersection with that upper rock source bed. The combination of almost no upper source material and a very low success rate for rocks reaching the bottom makes this a relatively low-risk source. The bottom outcrop source (at elevation 8375) is only about 200 feet uphill from the proposed addition. Although any spherical boulder that originates at the lower source would almost certainly reach the house, a careful look at that source layer has identified only one boulder that seems threatening at present. There are quite a few slabby boulders that are lying at the ground surface in this lower zone, but they lack the mobility to roll and bounce. There could possibly be some small potential for slabby or tabular rocks to break free during the winter season and slide along an icy snow layer and down into the addition. A low berm or wall could be an effective structural mitigation against this possibility. One specific 3 foot boulder in the lower source outcrop that is within the potential rockfall path does seem somewhat threatening. It has weathered to a roughly spherical shape and requires relatively little additional weathering around its base to break free. It could remain stable for centuries or it could become unstable next season. If it were to bounce downhill it might either roll into the addition, or it might instead break apart along its several deeply-weathered fractures into several slabs that won't roll or bounce. It does represent a potential threat, and it seems to be the principal predictable threat on the hillside. It is also readily accessible for proactive mitigation, which is recommended. PREDICTION OF FUTURE ROCKFALL EVENTS Some change in state is required to initiate a rockfall event. Rockfall events are usually triggered either by a mechanical stimulus of some sort, or by gradual loss of strength or restraint at the support point of a boulder. Loss of strength due to weathering is a continual process that progresses at a geological rate, over thousands of years, as the hillside gradually erodes and falls away. One characteristic of these dirty sandstones of the Minturn Formation is that the boulders themselves weather smaller with time, and that only the more resistant layers contribute boulders which can outlive the slope erosion process and therefore need to tumble downhill. This is a very slow, very sporadic, and unpredictable process. Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 8 of 10 Heavy rains may contribute to instability in several ways. They may reduce the effective strength of the supporting material by increasing the water pressures in the ground, they may erode the underlying supporting material, they may build up water pressures that tend to push a boulder out from the slope, and they may wash material into a crevice that works to wedge a boulder outwards from the slope. Periods during and after heavy rains are notable on highways throughout the state for the rockfalls that litter the highways. Periods of heavy, monsoon-type rain are therefore statistically much more prone to rockfall events, but are seldom predictive of specific rockfall events. Snowmelt seasons contribute to rockfall initiation in two ways. One is through the daily meltwater influx that affects the boulders as indicated in the previous paragraph. Another is through the nightly/daily freeze/thaw that incrementally pushes boulders out from the slope, since ice is 10% lower in density than water and expands 10% as it freezes. Snowmelt season is another statistically important rockfall season, but once again it is seldom predictive of specific events. Seismic acceleration is the initiating factor in many rockfall events. Magnitude 4 is the level at which many people begin to personally experience the sensation of shaking during an earthquake, and that also corresponds approximately to the lowest levels at which seismic- induced rockfalls have been documented. The region surrounding the site has been mostly free of recent faulting or recent significant earthquake activity. Although there have been many smaller ones, there has not been a recorded earthquake of magnitude 4 or larger within 50 miles of the site during the 40 year period of sensitive seismograph measurements in Colorado. In summary, there is no way to predict the occurrence of any specific rockfall event in the future. The only certainties are: 1) that the highest potential for individual rockfalls will occur during spring snowmelt and summer monsoon rains, 2) that rockfall could be initiated at this site during a rare major seismic event, and 3) that eventually, sooner or later over the long term, all of the boulders on this hillside will either weather away or fall or slide downhill. The expectation is that some rockfall will occur, but that it will probably be extremely infrequent on a human time scale. CONCLUSION This review was limited to establishing whether a significant degree of rockfall risk exists. It is not possible to predict when or if any specific rockfall would occur, and it is not possible to definitely rule out the possibility of a damaging rockfall. This is a common problem for rockfall zones worldwide. In my opinion, except for the single noted boulder, there is a very low expectation for a damaging rockfall to occur at this site during the life of the addition. However, this site does fit the minimum criteria observed at rockfall sites worldwide, and computer calculation of the Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 9 of 10 kinetic energy involved indicates that damage could be significant if a rockfall does occur and if structurally critical support points or people were to be impacted. This definite potential should be understood and accepted by owners in their use of this property, and designed for accordingly if this small risk is not acceptable. Thank you for the opportunity to work on this project. Please call if you have any questions. Sincerely, William Klauber, PE 34906, Colorado Box 909 Leadville CO 80461 719-486-5780 Rockfall Potential, Nate Ford Residence, 1079 Sandstone Drive, Vail Page 10 of 10 � uMRroMurw. raasaaC 8800 8700 8700 8600 � � i 8600 F � na� r� FaWsrzv Mn 8500 3 �R 8500 8900 n� � 8400 8300 � r 8300 8200 rornnar� 8200 ILL a,:uPFr- LI p1AfE FOW W5112NCT.0 1019 5AN125fOW WK., VNI. 5WM PROFU I LION - S RID GE S UBDIVISION A RES UBDIVISION OF L 0 T A 3.9 BLOCK A TOWN OF VAIL EAGLE COUNTY .9 COLORADO CERTIFICATE OF DEDICATION AND OWNERSHIP SURVEYOR'S CERTIFICATE Know all men by these presents that Walter Regal, being sgle I dq hereby certify that I am a registered Sri owner in fee simple, of all that real property s'ltuated In the under. the taws o the State of Colorado, th�it Town of Vail, Ea g Y le County, Colorado, described as followst correct and complete as laid out, platted, r hereon, that such plat was Trade from an acc , Lot -3, Block 'A', Lion 's Ridge Subdivision, according to, the property by r�,e and-under my. supervision. ands- plat thereof recorded in the office 'of the Eagle County, location and dimensions of the lots, easeme Colorado, Clerk and Recorder, containing 0,944 acres, more or sale subdivision''as the same are staked upon 4 less, compliance with applicable regutations goner'A, of land, has by these presents toid out, platted and subdivided the same SET PIN & CAF into lots and tracts as shown on this final plat under the name In witness thereof I have set my hand and set ' ,---' L.S. 26598 and style of ', Lion 's Ridge Subdivision, A Resubd i v i s I on Of Lot A,D. , 199_, -3, Block A ', a Sudivlsian In the Town of Vail, Eagle County, Colorado' and does hereby accept the responsibility for the f=1 2a Cpl completion of required improvements) and does hereby dedicate and �� ` set apart alt of the public roads and other public Improvements R=1 001 . 4 ��� / '1' and places as shown on the accompany I ng plat to the use of the Stan-Hogfe ldt L= 295.04 public forever) and does hereby dedicate those portions o said Colorado Hda PLS 2 T= 1 j rent property wh Ich are Indicated as easement on the aecort anyIng LO=2 ��' -lip plat a easements for the purpose shown hereon) and does hereby CB=S 57'4 grant the right to install and maintain necessary structures to \ ® the entity responsib.te for prov(ding the services for 'whlch the NOTESs easements are established, (1) The purpose of this plat is to subdivide` � J�/• / � :�,,,, FOUND 21 WITNESS COINER t parcels as shown , 1 Executed this _____ day o A. 199_. C2) Date of .Surye t January, s / y No. 5 REBAR & TAG " Y -------------------------- b i 9 @5. `.' L'/ • ` L.S. 4043 t ) Bearings ire ased on l n con n ect I n g . arking the' wes+erly and southerly corn .' N _ '•,` i' 4 �,. \` O E + - --- being S44`37'06SE (see drawing) , Walter Regal -_ _________ C ) Monumentatlon as shown hereon , ` f 13275 W. urlelgh Road (5) Street Addresst ..Lot A-3E - ----- Sandstdl SCALE: 1" = 20' f,r n /f \ 1.0 Brookfield, WI 53005 - • Lot 3W - --_ an -i�r t A- S ds '� (6) Protective Covenants recorded in Book / BUILDING , . 2Q / /°f _----` ''' 20 0 40 60 F et `� � ✓/.- . .. _. . OUTLINE kfEN / STATE ®F_------ -_ --- .- __ EASE - PLAT RESTRICTION COUNTY OF _ o.o Z For zoning purposes, the two lots created by'*1 � i /,. / ✓ The foregoing instrument was acknowledged before me this __ are to be treated as one entity with no morel r' --- Y day of ____-____-e_____, A,D , l99__ by Walter Rega t. residences all owed on. the combined area of t! Allowable gross residential floor area :for. tK y Commission explresi ___ ___ res.I den ces wilt be caIcutated based on the c` W i to ess my hand and seal . two Lots. --- r �f ____________________________ 0.4719 ACRES �' � Notary Public ZONING ADMINISTRATOR CERTIFICATE SANDSTONE DRIVE �;f' �� Address�---_-__-- _______________ / S / _________ _______________ sr�® i�' This final plat is hereby approved by the Tome: p Administrator this day of 10.0 2®6.50 r l �,ri poi ,, Attest t FOUND No. 4 REBAR & WASHER , -� t�, ��/ J L.S. 1511 - - - - - - - -- ----------- TITLE CERTIFICATE Town-Clerk - - ---- Zoning AdmInIst*% - Town of Valk, Colorado Town of Va i l, _______________________ _____ does hereby certify that the title / ! to all lands shown upon this final plat has been examined and is BUILDING I' ! / vested I n L. :T A--3 ____________ _j____ ________________® ------------- ____ _ '' OUTLINE ',,/ / // � _____ CERTIFICATE DE TAXES PAID t EASEMENT 0 4719 ACRES // / ,� // and that title to such lands I s free and_clear of all t lens-an SANDSTONE DRIVE f ' / encumbrances, except as follows! I, the undersigned, do hereby certify that the \ / �� ✓ ,� ----------------------------- __ ______________ --_____________ taxes due and payable as of _ _ �__----- ------------------------__--------------------------------------- parcels of real estate descrI bed on thIs�fInaA ----------------------- ----------------- -- --------------- full , --- - NOTES: ------------------------------ ----------------- ___ . __________ Dated this . - day of -----_______________, F ' 1 THE PURPOSE of THiS PLAT .IS TO. SUBDIVIDE 1_OT A-3 INTO TWO LOTS. _ � ,f� if/ f f 2: DA OF SURVEY- JANUARY, 1995. -------------------------- ___----------------- _-_____®_____-- Treasurer of Eq l / EET DR LOT.A-3 E - SANDSTONE DRIVE. 10.0 \ / {, LOT A-3 W SANDSTONE DRIVE. y '� �,, Dated this day of ________________________, A.D, , 19__ 4. ONUENTATiON SHOWN ON DRAWING. °___ Q 5. IS OF ELEVATION IS A LINE CONNECTING FOUND MONUMENTS AT THE CLERK AND RECORDERS CERTIFICATE / WESTERLY AND SOUTHERLY CORNEPS OF LOT.A-3 BEING - S 44-37-OT E. (SEE DRAWING) ---®__ _____________ ____________ This final plat was filed for record in the oCr 6.) PROTECTIVE COVE RECORDED iN BOOK AT PAGE (T i t l e Company) , on this!s____- day of � \ /� �} Address t and Recorder ---------�. __________________________ 199 at _-___o'clock __ M, Recorded under Rete --------- --------------- -----------In Book --- - at Page ----- Byl LOT , `\ �� �/ SET No. 4 REBAR & ALUMINUM CAP CS i gnature)_ ----------------- • \ f LS. 26598 . Clerk ana Rec®r>~ A® O `� _______________________________ Eagle Count, Co=t - ----- ----- -- -- -------- f'� (Print name and title)- B / �, • ,ys�s �` y Dy___ eput 01- NOTICE: According to Colorado law you must commence any legal action based ( 1® 1 21' upon any defect in this survey within three years after you first t i discover such defect. In no event, may any action based ,upon any FOUND No. 5 REBAR & PLASTIC GAP 4116.93 defect in this survey be commenced more than ten years from the. ALPINE ENGINEERING L= .04 date of the certification shown hereon. T-- 49.02 C13=1 S ' ® 98.04 41199 HIGHWAY 6 & 24, EAGLE-VAIL P.O. BOX 1230 EDWARDS. CO. 81632 303 949-1406 2/7/95 PATRICK FILIJETTAZ LION'S RIDGE SUBDIVISION A RE.SrUBDIVI,S"ION OF LOT A-3, BLOCK A X 1079 Sandstone Houses - Vail Co X TOWN OF VAIL, EAGLE COUNTY, COLORADO x N CO WEST HOUSE EAST HOUSE o� arm,ww .�.awe. v.o.nb m co 2 -aC51'3Y d R-eppa.64 r-a4e:s�a ` ,pa�n IXCEPTEO w u h..yn°mY°mait°'.r4Oew. �, f e.Ys.e.ep 'T' 39"C� �fi 5we wno wad o M O SGYE 1'�.2ff n c{, Maaceiv MawiMrxaw.in wd` Z n.w o-•0'�o nnr....a r�.s,.q. 0-2 Mr. Mr. LU °'°` muw anlnosvrara arKk.� = p r;m ...r. r� LOT A-3 W l M su!wu,c or ram uar ,r✓/ / i .YrrM a en jai, .w t .,,..ei M R - � �Oj� iY./'F ]�u.�4wa.ea p..w•on iry nre,w LOT e` r'!!f� fa A-2 ',fir �1 `: cw co..r.c. �Y 0 w 5 4,10, _ _ (s•4118.93 W-S4r5~w- AREA CALCS (WEST AREA CALCS (EAST)-. WEST HOUSE-SITE COVERAGE= 1,192 S.F. EAST HOUSE-SITE COVERAGE= 1,467 S.F. > WEST HOUSE-GRFA CALCULATIONS: EAST HOUSE-GRFA CALCULATIONS: TOWN OF VAIL ZONING REGULATIONS TOWN OF VAIL ZONING REGULATIONS �_ O 0 J BASEMENT PERCENTAGE CALCULATIONS: BASEMENT PERCENTAGE CALCULATIONS: 4—j[ )f WALL SURFACE= 1,454 S.F. TOTAL WALL SURFACE= 1,407 S.F. 0- O TOTAL UNEXPOSED WALL SURFACE=533 S.F. TOTAL UNEXPOSED WALL SURFACE=555 S.F. U) PERCENTAGE OF PERCENTAGE OF S UNEXPOSED WALL SURFACE=37% UNEXPOSED WALL SURFACE=40% m (n BASEMENT LIVING AREA =618 S.F. BASEMENT LIVING AREA =618 S.F. �/'� p') GARAGE AREA = 479 S.F. GARAGE AREA = 479 S.F. �+) rl- -TOTAL LOWEST LEVEL = 1,097 S.F. TOTAL LOWEST LEVEL = 1,097 S.F. O BASEMENT DEDUCTION (37%) = -405 S.F. BASEMENT DEDUCTION(40%) =-438 S.F. _ ✓ BASEMENT SUB-TOTAL =692 S.F. BASEMENT SUB-TOTAL =659 S.F. 0 GARAGE EXEMPTION =-479 S.F. GARAGE EXEMPTION =-479 S.F. BASEMENT GRFA TOTAL =213 S.F. BASEMENT GRFA TOTAL =180 S.F. MAIN LEVEL AREA = 1,192 S.F. MAIN LEVEL AREA = 1,467 S.F. MAIN LEVEL GRFA TOTAL =1,192 S.F. MAIN LEVEL GRFA TOTAL =1,467 S.F. a_ o_ ;N N UPPER LEVEL AREA =570 S.F. UPPER LEVEL AREA =849 S.F. N N UPPER LEVEL GRFA TOTAL =570 S.F. UPPER LEVEL GRFA TOTAL =849 S.F. O N I TOTAL GRFA =1,975 S.F. TOTAL GRFA =2,496 S.F. o N The deduction shall be applied to all horizontal areas on The deduction shall be applied to all horizontal areas the lowest level of a structure,including garages. on the lowest level of a structure,including garages. X X X X N 00 16'-5" 16'-5" N !_ C U N (0 0 d ADDITION: ADDITION: 279 S.F. 275 S.F. ° T W 0 a E Z M O p U 0 °;u 4+�l U 016 6 J 7 u ■ _ W C I co O e0 O UPPER LEVEL. MAIN LEVEL/,>< ¢ a a 3 -- — -570 S.F.-- — 1,192 S.F., N I CAI 521-0. n W/� VJ O � 52'-0" KXA EAST HOUSE: GRFA CALCS. 21 .31,2 Q D Ljj 4-a (L) AREAS FROM FLOOR DIAGRAMS THIS SHEET: 0 / O LIVING AREAS(BEFORE ADDITION) =2,380 S.F. �, _0 U) ADDITION ONLY =554 S.F. GARAGE: LOWER LEVEL:, TOTAL LIVING AREA =2,934 S.F. N 479 S.F. 618 S.F. N (n GARAGE AREA: =479 S.F. N " V � ) O AREAS FROM TOWN OF VAIL ZONE CHECK 9-15-2006: 23'-2° 2'-10° s'-o° 18'-0 " Q� LIVING AREA =2,481 S.F. o ADDITION AREA =576 S.F. N Q TOTAL LIVING AREA =3,057 S.F. r 0_ FLOOR PLANS EAST N 1 if = 10'-0" N_ O N X X X X N r L I � Q E UPPER LEVEL: " 570 S.F. o a W 0 J a E Z m i; 0 Y aqA u 9U m ■ 7 w E z U 3 E x M �d n of 0 a A 52'-0" ` MAIN LEVEL:' :1,192 S.F. '�rn/� N V/ O TO c) WEST HOUSE: GRFA CALCS. O CID AREA FROM FLOOR DIAGRAMS THIS SHEET: LIVING AREAS =2,380 S.F. J LI -1-0 N x� X GARAGE AREA =479 S.F. s2'-0^ a O AREA FROM TOWN OF VAIL ZONE CHECK 9-15-2006: LIVING AREA =2,461 S.F. 21'-31/2" A/Z� k \�/ � LOWER LEVEL: GARAGE: � �♦ 479 S.F. N X � 18'-0" 8'-0.1 2'-10" 23'-2" 0 (V G FLOOR PLANS WEST 1" = 10'-0" U N 0) N_ O N 00 r ._— L 00 V52'_�„ s_ _- 7 21:-5" - (� v' L co 2 ERtk'r 7 p rl EL $art- I r. W o rlra.. o E % I Z © M O O 0 U a oL _ ' • °� > W.T II I •Zu �r N,QRTI-WEST F EVATKDN SCALE for-r~v_ - - NC)RTHEA T ELEVATION TOTAL BASEMENT WALL:483 S.F. , r 'ryr<r. ekr.p =7 •u': "� `' ''°' TOTAL BASEMENT WALL: 166 S.F. "�� ° p a UNEXPOSED WALL:424 S.F. � �. " ,� ;,�� UNEXPOSED WALL:94 S.F. _ t_ r a - a_ h t J�.� 1T � � kWe_-_ 'FMtiI +•+r.Y� t� ,Kj� lJ9 lW i ,..",u, i<:-N.t — _. - s ° 1 FkW EL fie' Flfi f I i 1 •-'n _ _•il — ° I ..p- °q,fp"q.' --h'+ - ,r--a T� - - -_.c , r•.r _ ' - -0 i ! '� E I x w+*N hN - - era - - _ x • 11 x - O ZT,, p.Fermi 6W at OR-I W-91 1&27v--I� � I � � I -c m�- +i-rid,+ak Fr&m ed — — I 14 — - - - - - - ---- -I = r I I I s I T qtr r. �, =T I BASEMENT WALL SUMMARY(EASTI: TOTAL BASEMENT WALL:260 S.F. TOTAL BASEMENT WALL: 498 S.F. a TOTAL BASEMENT WALL = 1,407 S.F. co TOTAL UNEXPOSED WALL=555 S.F.(40%) UNEXPOSED WALL:37 S.F. N cy TOTAL EXPOSED WALL =921 S.F. (60%) � M �q I I , U) � N_ O N 2 ELEVATIONS EAST 00 1 11 = 101-011 °' 52'-0" 21'-5" X � X 00 —I r I r I � 1 I E 1 co III rerst Fm,t-F7 mar r° - #wIXiYdE W — O N CO" O U 2 I� U r _ w AF = r n W7 z o J: ■ x 7 Nr � o � TOTAL BASEMENT WALL:470 S.F. I �6195 m IV(lF�Ei411'I T E',_ES1�6TIi)h; _ ,"i� ",`� UNEXPOSED WALL:386 S.F. -NORTHEAST MA-27 �' �+° a o a TOTAL BASEMENT WALL:257 S.F. 211.51 521-011 V! Fo z _ O - - .. y �: I , i.yn W _ ✓1I " N uj _ I _ p , I k, • 1 I 1C!'� I'�!' � �1 ' _ . 0 F I } -0 . _ sT FL e�;l ,, , 1 ,1 1 6 M J 1 k as.e° k` 1 1" C/) I LpYf[n IJVM JbLNMAr F -IdE► ., 1'LL J'7iY4f`ST ELEwI€A1€}M -W)&rW-AST ELEVATIONI�� � ■ c Y1 BASEMENT WALL SUMMARY(WEST): co TOTAL BASEMENT WALL: 257 S.F. TOTAL BASEMENT WALL = 1,454 S.F. TOTAL BASEMENT WALL:470 S.F. TOTAL UNEXPOSED WALL=533 S.F. (37%) � w UNEXPOSED WALL: 147 S.F. TOTAL EXPOSED WALL =921 S.F.(63%) U) N_ O N 1 ELEVATIONS WEST 00 1 11 = 101-011 °'